Categories
General Home experiments Observations Science history slow Sustainability/environmental Tea

Coffee and the world

Welcome to the first post of 2018, Happy New Year! But before embracing 2018, perhaps let’s take a moment to remember those things that we discovered in 2017 that connect your coffee cup (or brewing device) with the physics of what occurs in the wider universe. Here are some of the highlights for me this year, if you want to share your highlight, please comment in the section below.

latte art, flat white art
A properly made latte. But what if you add hot espresso to the milk instead of the other way around?

1) Latte layering

In mid-December a study was published in Nature Communications that explored the complex, but elegant, physics involved in making lattes (ok, not quite by the technique that you would hopefully find in your neighbourhood café but keep with this…). When a hot, low density, liquid (espresso) was poured into a hot higher density liquid (milk) contained within a cold mug, the competition between the density gradients of the liquid (vertical) and the temperature gradient from the cup wall to the liquids (horizontal) produced multiple layers of varying coffee/milk concentration in the cup. Too late for a 2017 Daily Grind article, this looks to be too good an experiment to pass by, hopefully it will appear on the Daily Grind in early 2018.

 

science in a V60
Could this V60 mystery now be solved?

2) Bouncing drops

November 2017 saw research published about what happens when a cold droplet falls onto a hot liquid (think milk and coffee). The temperature difference causes currents to be established within the droplet (and in the main liquid) that in turn create air flows between the droplet and the liquid bath that prevent the droplet from merging with the bath. The research can explain why it is that you can sometimes see raindrops staying as spheres of water on the top of puddles. It may also explain a puzzling phenomenon that I have seen while brewing coffee in a V60.

 

Vortex rings get everywhere.

3) Vortex rings in coffee

June 2017 and it is again about adding milk to coffee (why do I drink coffee black?). When one liquid (such as milk) is dripped into another (such as coffee), it is very likely that you will observe the milk to form “vortex rings”. These rings are related to smoke rings and have, in the past, been proposed as an atomic model. This year however it was suggested that these vortex rings could form as a type of magnetic nanostructure. Mathematically impressive, beautiful, perhaps quite useful and mathematically similar to something you can find in your coffee.

 

bloom on a v60
How do craters form?

4) Crater shapes

April 2017. What happens while brewing a pour over? As you drip water onto a granular bed (or, in coffee terms, ground coffee in a V60 filter), each drop will create a crater. The size and shape of the crater will depend on the density of the granular bed (espresso puck or loose grounds in a filter) and the velocity of the falling drop. Fast frame photography revealed how the shape of the crater changed with time for different scenarios.

 

Coffee bag genuinely home compostable
How it started.
The Roasting House bag before it went into the worm composter.

5) A home experiment

Perhaps not quite in the theme of the other four stories but this is an experiment that you can do at home. Some have proposed compostable coffee cups as a more environmentally conscious alternative to ordinary, disposable, coffee cups. But how “compostable” are compostable cups and compostable packaging? Between May and September 2017, #howlongtocompost looked at how long it took the Natureflex packaging (used by the coffee roasting company Roasting House for their ground coffee) to compost in a worm composting bin. This one worked quite well. Within 17 weeks, it had been eaten by the worms. In comparison, the “completely compostable” take away coffee cup is still in the worm bin (although considerably degraded) 37 weeks after the start of the experiment. If you are interested, you can follow #willitcompost on twitter. Will it finally compost? I’ll leave you to place your bets but you may decide that a link to Brian’s coffee spot guide to re-usable cups will be helpful.

 

What will 2018 bring? Certainly there will be more composting experiments as I have a coffee bean bag from Amoret coffee, 3 different compostable cups and a compostable “glass” to try with the worms. But in terms of the science? We’ll have to wait. Meanwhile, if you have a coffee-science highlight from 2017, please do share it either here in the comments section, on Twitter or on Facebook. Happy New Year to you all.

 

 

 

 

 

Categories
General slow Sustainability/environmental Tea

Coffee cup recycling

a take away cup
It is recyclable, but not easily so.

That old subject again, the recyclability of take-away coffee cups. But before you groan about our disposable culture, there has recently been some great news, at least as far as the university sector is concerned. Regular readers may know of the Bean Thinking list of Top UK Universities for Coffee Cup Recycling. You may also be aware of just how short that list has been. Now though, there are signs of change. Perhaps because it is the start of the academic year, several universities including Oxford Brookes and the University of Bedfordshire have announced new schemes for recycling their cups with Simply Cups.

Owing to the way the cups are made it is extremely difficult to recycle them; although they are technically recyclable, very few companies have the capabilities. Consequently, the majority of the cups that we use for our take-away are just thrown-away, taking many decades to break down.

compostable, coffee cup, disposable culture
Using compostables can be a step in the right direction.

It is often our universities that do the research showing just how environmentally damaging our disposable culture can be. Nonetheless many university catering departments continue to serve coffee in “disposable” cups without putting in place any scheme to recycle them. Over a year ago I started a list of the UK’s top universities for coffee cup recycling. It would be thought that it should be extremely easy to be listed here. To be listed, all a university has to do is take a responsible attitude to it’s take away coffee cup use. Preferably, they would discourage take-away coffee cup use altogether. As Loughborough University recognises, slowing down, talking with colleagues over a stay-in (washable cup) coffee can be far more productive than scurrying away with your non-degradable cup.

However, often we feel that we don’t have time to sit down for a coffee and need to take-away. At this point, to be listed on the guide, all that a university would have to do is either invest in compostable cups (despite the caveats*, this is at least a step in the right direction) or institute a scheme to collect and recycle their coffee cups (as has been done at the University of Bath, Bedfordshire, Kent, Loughborough, Manchester Metropoliton and  Oxford Brookes University).

As may be apparent from the fact that the universities can be listed within this short article, the current list is woefully short. Even after the recent good news from Oxford Brookes and the University of Bedfordshire. Most universities, including my own are sadly still not on it. So, what can you do if your university is not listed here?

  1. If you think it should be listed but hasn’t been it is very highly likely that I just don’t know about it yet, please let me know by contacting me through email, Twitter or Facebook.
  2. If your university is doing very little to discourage disposable cup use: Write to the catering department and waste management department of your university to let them know your concerns. When writing, be aware of the fact that they have probably considered this problem before and are aware of the issues but have concerns/limitations that have prevented them from implementing a policy. Consumer pressure can help to change their minds but there may be (what appear to them to be) valid reasons that they have not yet done so.
  3. Use a re-usable cup. Even if your university does not charge extra for using a disposable cup/give a discount for using a re-usable (thereby encouraging the use of re-usables), systemic change starts with individuals. Be the start of the change you want to see. You can find a review of various re-usable coffee cups here.
  4. Refuse to buy your stay-in coffee if you are served it in a take-away cup. Good coffee deserves to be enjoyed in appropriate cups and poor coffee should be avoided anyway.

You can find the list of the UK’s top universities for responsible take-away coffee cup use here.

 

*The word ‘compostable’ does not necessarily mean that it will compost in a home-composting environment. For this situation to be preferable to the ordinary disposable cup, it would be necessary to have some form of industrial composting facility in place.

Categories
Coffee Roasters General Home experiments Observations slow Sustainability/environmental

How compostable is compostable?

the cup before the worm bin
“Completely compostable”
But how compostable is it?

So we’re trying to do our bit for the environment and ensure that we always get a compostable cup for our take-away coffee. But have you ever stopped to wonder, just how compostable is compostable?

It is a sad fact that most items that are described as ‘compostable’ do not compost as you or I may expect. Throw a ‘compostable’ cup in a compost bin (or wormery) and you may be surprised at how long it takes to disappear. The reason is that the legal definition of compostable generally refers to industrial composting conditions. In contrast to the worm bin, or the home-compost heap, an industrial composting facility is kept at (58±2)ºC. In these conditions, something defined as ‘compostable’ by the EU regulation EN 13432 or the US based ASTM D6400 needs to have completely disappeared within 6 months but have 90% disintegrated to fragments smaller than 2mm by 12 weeks.

Perhaps it is not hard to see why the legal criteria are defined this way. How would you define common criteria for home composting? Although there is a (Belgian led) certification called “OK compost” by Vinçotte, there are as yet no widely agreed definitions for home composting. However, some companies do try to seek out truly home-compostable packaging. In the case of coffee specifically, one coffee roaster trying to keep their environmental impact to a minimum is the Nottingham based Roasting House. Although most of their packaging is paper, (recycled and recyclable), they needed something less permeable for transporting pre-ground coffee by post. Apparently this took quite a search as many bags that said they were home-compostable turned out not to be. Eventually however they chose Natureflex, a packaging that provided a good moisture and air barrier to protect the coffee but that also broke down in a home composting environment.

But how quickly would it disappear in a worm-composter? On the 6th May 2017 my coffee from Roasting House arrived double packed. First in a Natureflex compostable bag and then in the standard (recyclable) paper bag/envelope. It was ready to be placed in the worm bin on the 8th of May 2017.

See the video below for how long it took to be eaten by the worms:

Seventeen weeks later, on 4th September, it was time to declare the bag composted. After 17 weeks, the bag had started to become indistinguishable from other items in the worm bin (such as garlic skin) and when I picked up what bits seemed to remain, they quickly disintegrated in my hand. It seemed time to declare it over for the bag. A truly home-compostable bag, but how does it compare to the ‘OK Compost’ label of Vinçotte.

Coffee bag genuinely home compostable
How it started.
The Roasting House bag before it went into the worm composter.

The definition used by Vinçotte is not for a worm-composting bin but a standard home-compost heap. Ignoring this fact for the time being, the certification requires that a compostable item disintegrates to pieces less than 2mm within 26 weeks and has fully gone within 365 days when held (in a compost bin) between 20-30ºC. Within these criteria, the packaging from Roasting House is certainly “home compostable” as determined by the worms. Although there were bits of greater than 2mm after 17 weeks, just handling them reduced their size to bits in the mm range. And that was only after 17 weeks, well within the 26 specified by the criteria used by Vinçotte.

So now we’re just waiting for the coffee cup. That went into the worm bin on the 20th April 2017 and is still going, 21 weeks later. Will it be home-compostable? Will the lining that’s needed to keep the coffee from leaking out prevent the worms from breaking it down? You’ll find out here! Make sure you sign up to the BeanThinking newsletter or follow @thinking_bean on Twitter or Facebook to be one of the first to find out when the coffee cup has finally gone.

In the meanwhile, if you’re looking for an environmental solution to your take-away coffee cup habit, it is worth investing in a re-usable cup. Most councils at the moment do not provide industrial composting facilities. Moreover, it is not safe to assume that compostable items will eventually compost in a landfill as modern landfills are water-tight and air-tight. As they say here, the modern land fill is not designed to mulch as much as to mummify. So,if you want to avoid green-washing, you may want to invest in a re-usable cup, for a review of these see Brian’s coffee spot here.

 

 

Categories
Coffee review Observations slow Sustainability/environmental

A need for religion at Continental Stores, Russell Square

exterior of Continental Stores
Ghosts of shops past! Continental Stores on Tavistock Place

Many years ago Tavistock Place, now home to Continental Stores, was on my cycle route home. I can no longer remember whether the sign “Continental Stores” was visible then or whether it had a second sign over it. However, the faded red backdrop, the vintage font and the whole feel of the frontage does make “Continental Stores” (the café) stand out a bit from the crowd. Continental Stores is run by the same people who run Store St Espresso on Store St. but much of the original decoration of the café has been kept from the old shop that previously occupied this space. And although this ‘new’ branch is now more than three years old, for various reasons I’ve never quite got to visit until a couple of weeks ago.

We arrived fairly late, just half an hour before closing, and managed to get a long black before the espresso machine (which was apparently having a bad day) finally packed up. Although filter coffee was available, this is not the case when you arrive so close to closing. The coffee was however very drinkable and the window seat provided a great place to watch people pass by. Bubbles formed around the edge of the coffee, reflecting the light streaming through the window in this airy café. White mists skitted over the surface of the drink. There was plenty to consider in the café too, from the oil paintings on the wall to the subtle green colour of the glass separating the interior of the café from the bar area (for more on glass colours click here). A large amount of science in a cosy place. However today’s train of thought took a somewhat different direction. That day, sitting in the café, prompted a thought train to develop in a more introspective direction: what does climate change denial have to do with personal integrity and the need for a continuing dialogue between science and religion? And what does that have to do with coffee drinkers?

Incredibly, it started with a map.

glass and map interior Continental Stores
So much to contemplate! From glass to the map.

On the wall in the main area of the café, behind the counter, is a map depicting the world. Although there is a photo on this page, there is a far better one in Brian’s Coffee Spot review of Continental Stores which can be found here (scroll through the gallery to find it). Also on the map are two circular depictions of the Polar regions. That fact, that the poles are illustrated separately and that the map is a rectangular impression of our spherical home impressed on me the knowledge that it is extremely difficult to truly represent our globe on a flat piece of paper. All maps are projections and the one at Continental Stores is the familiar cylindrical projection where you imagine a cylinder of paper wrapped around the equator of the Earth and then project the profile of the countries around onto it.

A few years ago a Malaysian-Chinese lady, now in her 70s told me a story about growing up in Malaysia (then Malaya) under British colonial rule. At school it was always impressed upon her how much larger Britain was than Malaysia, you could see it just from looking at the maps (which were always of the cylindrical projection as displayed at Continental Stores). It was only later that she realised the importance of map projections. Although Malaysia, at the equator, was fairly well represented by the cylindrical representation, Britain, being relatively closer to the poles, was stretched and so appeared much larger. Britain is in fact larger than the Western Malaysia peninsular but not to the extent that it appeared from the map. Had the map projection been used as a subtle political tool justifying Britain’s rule over Malaya*?

Similar thoughts occurred to me recently with some of the comments that have followed hurricane Harvey in the US (and the floods in south Asia that have killed more than 1200 people but have sadly been far less reported here in the UK). Was the intensity of the hurricane, and the fact that we are experiencing similarly intense storms more frequently, a consequence of climate change?

message inside Continental Stores
From the table to our planet. A message with resonances.

Although that’s an interesting question, it’s not the one that I would like to consider today. Instead, it’s the response on social media generated by data about the frequency of the hurricanes and their strength. “Why are you only showing weather information for the past X years, if you look back further/look more recently…” etc. It is the same with graphs showing global temperatures as a function of time. People ask “Why are they plotted that way, if we looked back further/zoomed in a bit more….” It seems that there is an accusation behind many of the questions; there is doubt about the integrity of the scientist who circulated the graph. What is at the root of this?

When writing a scientific paper (even on a relatively uncontroversial topic like magnetism), there is frequently a lot of discussion about exactly how to present the data. The graphs need to be clear enough and on a scale that the ‘message’ of the paper is delivered quickly. But equally in a way that does not misrepresent the data. Then, different authors have different ideas on aesthetics. The final graph is a balance between these. So why is there such distrust of similar graphs presented on subjects such as climate change? Are we so used to being sold messages in adverts that we immediately suspect the scientists of an evil motive, trying to persuade us to ‘buy’ an ideology?

Clearly there are occasions on which data is presented in a manner to impress rather than to reveal, as was the case with the map. Though even with the map, there is some ambiguity. Some cylindrical projections can be helpful for navigators as lines of latitude and longitude cross perpendicularly. There are times when such a representation would be useful. So when we generate, share or read such  graphs, we need to ask ourselves questions about our reaction to them. Are we representing the data truthfully? Are we trying to make the data fit into opinions that we already hold? These questions apply equally whether we are creating the graph or if we are seeing it on social media and reacting to it.

black coffee Continental Stores
Bringing it back to the coffee. The bubbles reflect the light from the windows. Taking time to contemplate the drink gives us space to reflect.

These considerations generate questions of their own. What do we think science is? Do we believe in the existence of truth? What is truth anyway? What are my motives in sharing/reading this piece of information; am I trying to understand the world or manipulate it to my advantage?

Which is just one reason (of many) that a respectful dialogue between science and the humanities, between scientists and theologians is desperately needed. Religions and philosophies have been asking questions about the nature of being, questions of truth and motive for millennia. Tools such as the examination of conscience have been developed by religious traditions to allow us to interrogate our own motives and to start to understand our own behaviour. In a week when it was revealed that more than 50% of people in the UK describe themselves as having ‘no religion’ it seems to me that, whether we believe in a religion or not, many of us would benefit from such an examination of conscience before we hit ‘retweet’, ‘like’ or ‘share’. Questioning our motives before creating, sharing or commenting. But such tools require space and the time taken to slow down, perhaps in a café, to deliberate on our own attitudes. Time that is needed to help us to see if it is our behaviour that needs amending before we question the integrity of others.

Such deliberations often don’t have conclusions but instead open up more questions. The fortunate consequence of which is that it becomes imperative that we spend more time contemplating our coffee in quiet, welcoming and thought provoking environments such as that found at Continental Stores.

Continental Stores can be found at 54 Tavistock Place, WC1H 9RG.

*I have kept the name of the country Malaysia as it is now known apart from when referring to the time when Britain had colonised it and called it “Malaya”.

 

Categories
Coffee review Observations Sustainability/environmental Tea

Breathing underwater at the London Particular

table and inside of the LP
Inside the London Particular

Tucked out of the way in New Cross, the London Particular has always been just that little bit far away to travel to, but always so tempting, a siren calling towards New Cross. The reviews of the food and the place were intriguing, while the coffee is roasted by HR Higgins, a roaster with a café that always seems closed when I get the opportunity to pass by (which is usually Sundays). So it was with some relief that I finally managed to get to the “LP” a couple of weeks ago. Towards the end of a row of shops, the space outside the café has plenty of seats where you can enjoy a spot of lunch and/or a coffee on a warm day. Inside feels more cosy. A bar on the left of the entrance forms a corridor with the wall that you walk through to get to a room with communal table at the back. In addition to the communal table, there are a series of individual high chairs along the wall. At the back of the café is a window with an old device sitting on it. “An old digital multi-meter” I said before being corrected by my sometime companion in these reviews, it has a dial, it must be an “analogue multi-meter” then! It did seem to be able to measure current and resistance and it did have a dial to indicate the value measured. Quite why it was sitting, unconnected, on the windowsill is anyone’s guess.

AMM, LP, NC
An Analogue multi-meter. But why was this sitting on the windowsill at the back of the cafe?

The lunch menu is good. Enough items there to provide choice, few enough that each can be done well. Significantly, the true London Particular, the pea soup, was not on the menu on the day we were there. We had a light bite of lunch, a black coffee and shared the jug of mint infused tap water that was placed on our section of the table. At the other end of the table, another customer was enjoying her lunch. So although communal, the table gave us enough room to be private and have our own conversation. A mirror along the wall above the table reflected the blackboard menu between the table and the bar. Thinking about mirror writing reminded me of Dr Florence Hensey and his letters of lemon juice ink. Back in the eighteenth century he had operated as a spy out of coffee houses on the Strand and in St Martin’s Lane¹. Spying on England for France, his letters, written in lemon juice (invisible ink) passed without detection before the frequency of correspondence drew suspicions. Times move on. Spies would surely no longer write in lemon juice or even mirror writing to avoid detection.

Lunch on a week day was a very good time to experience this café. It must get quite crowded at weekends or brunch times. So it was good to be able to sit back and contemplate our surroundings from the back of the café. In the foreground of our view though was the water jug. With fresh mint leaves stacked inside, it was evident that air had become trapped under some of the leaves forming tiny bubbles. How had the air got stuck there? Was it merely that the leaf was blocking the air bubble from rising through the water? Could there be slightly more to it?

Coffee and mint water in New Cross
Coffee and mint water at the LP

There is a popular expression “like water off a duck’s back”. Perhaps it arose because the duck’s back is often thought one of the most waterproof surfaces we know. But what makes the duck so waterproof? Why does water just form drops and then fall off the back of the duck? It is not because the feathers are oily. We sometimes ‘wax’ our waterproofs with a grease to make them resistant to getting wet and so perhaps we have thought that the duck’s back was just a bit greasy? And yet a study done back in 1944 showed that mere oil could not account for the waterproofing of the duck’s back.

Before delving into why the duck’s back is such a waterproof surface, it’s helpful to know how to quantify ‘waterproof-ness’ in the first place. To measure how waterproof something is, we use what is known as the contact angle, which is the angle that the drop makes with the surface on which it is sitting. Surfaces that are not waterproof (technically we call them “wettable” or hydrophilic), have very low contact angles, the ‘droplets’ of water on the surface are flattened. Waterproof surfaces on the other hand (imaginatively called hydrophobic), have contact angles which are much greater than 90º (it may be helpful here to have a look at the cartoon illustrating this point). Droplets that formed on a duck’s back had contact angles much greater than 90º, indeed, they formed almost spherical drops of water. What could be going on?

artemisdraws cartoon, contact angle, wettability
How ‘wettable’ a surface is can be defined by the contact angle that the drop makes with the surface. Image thanks to artemisworks.

The answer is in the details of the feather. The feather is not a flat surface but a material that has irregular protrusions and structure at the micro and nano-scale (one thousand and one million times smaller than mm scale respectively). These protrusions trap air within the feather and so effectively suspend the drop above the feather surface. The droplet does not have a flat surface on which to spread out. The structure means that the contact angles of the drops of water on a feather can be even higher than 150º; the droplets are held up almost as if they are spheres of water.

mint infused water at the LP New Cross
A breath of fresh air under water. Air bubbles trapped under mint leaves.

Another creature that uses the irregular protrusions on the hairs on its legs for waterproofing is the spider. The hairs on the legs of a spider mean that, just as the duck’s back, the spider’s legs are extremely waterproof. But it also means that air is trapped under the droplets. Consequently, if a spider finds itself submerged under water, the air under the droplets forms little bubbles similar to those under the mint leaf in the London Particular. And this allows a drowning spider the air it needs to breathe. Nanostructure helping the duck to dive and the spider to survive. And the mint water to be particularly refreshing on a warm day in a very pleasant place for a spot of lunch and a coffee.

 

 

 

The London Particular can be found at 399 New Cross Road, SE14 6LA

¹London Coffee Houses, Bryant Lillywhite, Pub 1963

Categories
Coffee review Observations Science history Sustainability/environmental Tea

Looking under the surface at Mughead coffee

Mughead Coffee, Coffee in New Cross
Set back from the busy A2, Mughead Coffee offers a space to unwind.

A new café has just opened in New Cross. Mughead Coffee opened in July 2017 and sits fronting the A2, part of an old Roman road connecting London to Dover. The large pedestrianised space outside the café provides plenty of room for a few tables together with some further chairs arranged along the café window. It also means that the cafe is set-back far enough from the road that it is possible to sit outside and enjoy the surroundings. Inside, there were plentiful seats but, sadly equally plentiful numbers of occupants relaxing in this new cafe. Clearly this new coffee place in New Cross is proving popular. And why not! Just down the road from the London Particular, Mughead Coffee serves Square Mile in a friendly atmosphere. It is easy to see this becoming a popular local haunt. The usual array of coffees were on offer together with a filter option but as we arrived shortly after lunch, the cake/edible option appeared a little depleted. The interior of the café is quite light and airy with comfortable chairs at the back and more regular seating towards the front. We ordered a long black and a ginger beer and then adjourned to a table outside to await our drinks.

The tables outside are arranged on a sloping pavement. This is not really a big deal, but did remind me of a comment made by the lecturer who was trying to instil experimental design into us as undergraduates: The only stable table is a three legged one. However there was not much time to reflect on that as very soon both coffee and ginger beer arrived with a glass of ice. The natural light revealed the oils on the surface of the coffee as they moved with convection. Different convection zones moving in the coffee just as air parcels do in the sky to form mackerel skies or hot lava moves to form different rock formations, both on Earth and elsewhere.

coffee and ice in New Cross on a wooden table
Coffee and ice at Mughead Coffee. Note the reflections on the coffee surface.

Once the ginger beer was poured into the glass, the ice cubes floated upwards with just a fraction of them bobbing above the surface, the majority of the ice cube beneath. A glance around our surroundings revealed other hints of sub-surface structures. A drain cover nearby indicated, together with some tiling along the pedestrianised zone, the line of the rain sewer running along the road. A public telephone box had no wires obviously leading from it meaning that all the wiring for the communication had to be subterranean. And a raised flower bed, full of thriving plants, had a little drainage hole right at the bottom in order that heavy rain storms did not drown the plants.

This last feature reminded me of a documentary I’d recently seen concerning climate change. Often we tend to think of climate change as involving things that we can see: the melting of glaciers or the disappearance of sea-ice, or freaky rain storms that cause local flooding. However there is another aspect, a sub-surface aspect, that has perhaps been far more visually alarming than even the break-off of the Larson A, B and C ice shelves. If only we could see it. The problem is that, as it happens below the surface of the sea, few of us see it, it is hidden from view and therefore easily hidden from our conscience. It is the drastic effect that rising sea water temperatures are having on a particularly unusual plant-animal combination, the coral reefs. Coral reefs such as the Great Barrier Reef just off Australia, are animals that exist in a symbiotic relationship with a particular type of algae called zooxanthellae. Although the ‘mouths’ of the coral eat passing zoo plankton at night, during the day, they get other nutrients from the photosynthesis products produced by the zooxanthellae that live within their skeletons. These plants give the corals those amazing colours (as well as food). In return, the coral provides the plant life with shelter (they live within the coral itself) and extra carbon dioxide.

Outside Mughead Coffee New Cross
Indications of a hidden architecture. Can you see the drainage hole at the bottom of the planter at the back of the photo?

As the sea temperature rises, the zooxanthellae become less efficient at photosynthesising and so of less use to the coral. If the temperature stays high, the coral ejects the plant life from its body causing the coral to lose all its colour, it has bleached. What sort of high temperatures are needed? It seems that if the temperature of the water is about 1-2°C above the usual seasonal maximum, the coral are ok for a few weeks. But if the temperature rise is 3-4°C (or higher) above the usual seasonal maximum, the damage can occur in just 2 days¹. Coral bleaching does not necessarily lead to coral death but if the bleaching is sustained vast areas of coral reefs can die and get destroyed, with significant impact to the local ecosystem. As corals host “nearly one-third of the world’s marine fish species…”² this impact will be far reaching and affect the livelihoods of millions of people³.

Although small scale coral bleaching has been documented since 1979¹, the first global scale coral bleaching occurred in 1998. It was 12 years until the next global bleaching event occurred in 2010. Following that, we have just had the third global bleaching event in 2015-16. In the latest episode, it is estimated that 29% of the Great Barrier Reef’s coral died (as in actually died, not just bleached). These temperature increases can be associated with global warming caused by increased greenhouse gases in the atmosphere (for more info click here (opens as pdf) or refer to [4]).

The frequency of these events, together with the fact that there were no global bleaching events prior to 1998 should be a dramatic warning siren calling on us to do something to arrest climate change. But what can be done and is it already too late? Well, it is not yet too late to do something. The plants, thriving in the box in front of Mughead can emphasise to us the importance of maintaining our local environment and by extension our global one. Taking time to slow down and take stock of what is beautiful in our environment, and the habits we need to develop to keep this for future generations, these are things that we can do. If you eat fish, was it caught sustainably? Some fishing methods can kill the coral reefs, check before you eat. This is not going to be hard to do. After all, we already do this with coffee. Many coffee drinkers (and roasters) will check how the coffee is grown and processed for both environmental cost and the conditions experienced by the farmers. Many such small actions can cumulatively build to an effort to stop climate change.

Which brings us, in a sense, back to the surroundings at Mughead Coffee. Sitting down and taking time to enjoy that coffee while appreciating our surroundings, the visible and the hidden, the busy road and the mini-oasis of plants in the planter, may help us to see that connectedness that pushes us to accept our responsibility to our common home. Contemplating the history of the road in front of us, will our planet still be beautiful in another 2000 years? With an offer of “gourmet sandwiches” on the menu (if only we’d got there early enough), there’s plenty of reason to head along to the old road in New Cross and sample the coffee while pondering our own impact on this interesting location.

 

¹ Life and Death of Coral Reefs, Charles Birkeland (Ed), Chapman & Hall, 1997

² Coral Reef Conservation, Ed Isabelle M Côté and John D Reynolds, Cambridge University Press, 2006

³ Chasing Coral, Netflix Documentary, 2017 (see trailer below)

4 Climate and the Oceans, Geoffrey K Vallis, Princeton University Press, 2012

Chasing Coral Trailer:

 

 

Categories
Coffee review Coffee Roasters Observations slow Sustainability/environmental Tea

Cobwebs, Crows & Coleman Coffee, Lower Marsh

filter, Brazilian or Guatemalan, V60, rainbow, glass, Coleman Coffee, Lower Marsh, Waterloo
There’s a lot of physics in this glass cup of coffee, enjoyed at Coleman Coffee, Lower Marsh.

Coleman Coffee on Lower Marsh, Waterloo, is a surprisingly relaxing place. Surprising because the frontage gives little away. A door with windows on either side revealing a small wooden bench on the right and a larger table on the left. A food menu is on the left, the coffee menu in front of you (above the counter) and a note about how the coffee is roasted on a black board on your right. The space feels open and welcoming but it is the garden at the back that I think shifts Coleman Coffee from being a lovely little café to a great spot at which to just spend time and notice things.

My first visit was on an incredibly hot day in early July. For some reason I didn’t see the filter coffee option on the menu and so chose a long black to enjoy outside. The shade of the trees was a welcome respite to the hot Sun and the contrast created by the light provided much to dwell on with the inadequacies of my phone’s camera. Berries had formed on the tree growing up the wall of the café. After my visit I read the review of the café on Brian’s Coffee Spot and realised that these berries were mulberries. The other trees providing the shade were a Jasmine and a Pomegranate. I also found that I had missed the filter option and so a return visit was obligatory! How easy it is not to notice things.

ditch the plastic straw, enjoy a paper one
Chocolate milk and a paper straw.

A second visit sadly revealed the restricted opening hours of Coleman Coffee. Arriving at about 2.58pm, we were told it was take-away only as they were closing at 3pm. However the third visit was worth the wait. By this time the weather had turned and it had been raining, but the garden was still calling. The filter coffee on offer (V60) was either a Brazilian or a Guatemalan. Opting for the nuttier of the two (an allergy to actual tree nuts does not prevent my enjoying nuttiness in coffee!), we took a couple of glasses of water through to the back and awaited our drinks. When they arrived, it was interesting to find that the nutty coffee was truly nutty. A lovely flavour and mouthfeel to enjoy. It was also great to notice that the straw in the chocolate milk seemed to be an old-fashioned paper straw (rather than the environmentally problematic plastic straws). As it had rained, the stools outside were a little wet, even though they had been largely sheltered by the same trees above the garden. This time, the mulberry tree seemed mulberry-less, apart from the one berry lying sorrowfully on the floor. The red of the berry being squished (accidentally) underfoot leaving it lying and injured in the style of Pyramus and Thisbe. Across the other (wetter) side of the garden, three spiders were busy weaving new webs, ready to catch whatever flies came their way. It would have been easy to watch those spiders for hours but I think a good café can linger in the memory long after your visit has ended and so the spiders are still spinning their webs in my mind now.

garden spider at Coleman Coffee Waterloo
Spider on the table. What could be better than time spent contemplating their webs?

Photos of spiders webs glittering with dew drops are common place but somehow strangely attractive. Beads of dew gather at various points on the web leading to descriptions of cobwebs as being laden with jewels. A few years ago, a scientist contemplating spider’s webs asked why it was that water collected like jewels on the webs? Why didn’t it collect similarly on your hair? (You can read more about his story here). The team looked at the webs of one particular spider with an electron microscope. Electron microscopes can magnify things far more than optical microscopes (for images of coffee under an electron microscope click here) and so the scientists were able to observe how the hydrophilic (wet-able) fibres in the web turned from ‘puffs’ to ‘knots’ as they got wet. Water falling on the web was then attracted to these knots, partly due to an effect caused by the knot shape and partly due to the surface tension gradient of the water along the fibres. The results of the study can be found here.

Although it took five years of investigation after the initial contemplation, this study of spider’s webs could lead to tools that could be used for water collection or in devices to aid chemical reactions. Which brings us to the other ‘C’ of the title: crows. Sadly there were no crows in the garden on either of my visits to Coleman Coffee. Nonetheless there is a link. My first visit had been cut a little short as I was headed to the Royal Society Summer Science Exhibition. Apart from the fact that it was baking hot inside the Royal Society, this science outreach event had a good mix of science/experiments for adults and for kids, it was great to wander around and learn a large number of new things. So many exhibits caught my eye but the one that connects with Coleman’s and cobwebs was the exhibit on tool making crows.

Spider and web, Coleman
Spider building a web at Coleman Coffee

Crows have been shown to be great tool users. Particularly the New Caledonian Crow which has been shown to even make hooks out of twigs in order to fish out insects from their hiding places. While thinking about what it was that led to this species of crow becoming adept at tool use (and therefore perhaps an explanation of human tool use), it became apparent that the two particularly good tool using crow species lived on remote islands without predators. Not only did they have the physical ability to create tools (a straight beak for crows, a thumb for humans), they lived in a place where they could have time to explore and to create, to develop tools to enable them to get the most tasty bug.

Just as the scientists had needed time to watch, to investigate and to think about spiders webs in order to create new tools, so crows may have needed that time to explore their tool use. Perhaps it’s worth pushing the analogy to inner-city London (or indeed wherever you are). The more we spend time out, contemplating and enjoying nature, the more productive we can be. But to develop, we need to slow down, to think, to contemplate, and to enjoy great coffee in surroundings as special as at Coleman Coffee.

Coleman Coffee is at 20 Lower Marsh, SE1 7RJ

Categories
Coffee Roasters slow Sustainability/environmental

Good news on coffee bag recycling & re-using air valves

air valve, plastic, environmental coffee packaging
Air valves and metallised plastic are common packaging materials for freshly roasted coffee.

Hopefully we’re all trying to reduce our environmental impact but there are things that we can’t seem to avoid. There is the saying “reduce-reuse-recycle”, but how do we do that with coffee bags? Can we reduce? How would we reuse? And recycling has, until now, seemed impossible.

The problem is that in order to keep freshly roasted (and particularly freshly ground) coffee fresh, it is packed in metallised plastic bags normally with an air valve. Metallised plastic is not recyclable in the general waste stream and so the air valve, even if it is made of a technically recyclable plastic material, is unlikely to be practically recycled.

There are questions as to whether it is necessary to package coffee in this way. A blind taste test by the Nottingham based coffee roaster Roasting House showed that, if your coffee was freshly roasted, a (recycled and recyclable) paper bag was a good option for packaging. Although the flavour profile was different for coffee stored in a bag with an air valve compared with the paper bag after 1 week of storage, the benefit to the taste did not seem to be worth the environmental cost if the coffee is delivered fresh to the customer (within 24 hours or so).

However, perhaps the roaster that you buy coffee from prefers to use the traditional metallised bags with air valves. What can be done there? Fortunately, there has recently been some great news on this front. Has Bean coffee have teamed up with TerraCycle to offer recycling of Has Bean coffee bags. TerraCycle are a company that specialise in recycling (or reusing or up-cycling) hard to recycle materials, such as coffee bags and coffee capsules. TerraCycle takes materials such as coffee bags and either repurposes them (TerraCycle’s website mentions repurposing juice pouches by sewing them together to make rucksacks) or pelletising them to be made into other plastic products.

Earth from space, South America, coffee
Our common home. Can we keep our coffee habit while keeping our home safe for future generations?
The Blue Marble, Credit, NASA: Image created by Reto Stockli with the help of Alan Nelson, under the leadership of Fritz Hasler

Sadly (but understandably), to take advantage of Has Bean’s offer to recycle your coffee bags you have to be a Has Bean customer. However, all is not lost. If you are not a Has Bean customer you can purchase your own recycling box from TerraCycle for coffee bags (prices start from £73*) or coffee capsules (prices start from £72.36*). Perhaps it is something out of the range of the general consumer but it may be something that smallish coffee roasters with a network of cafés could consider stocking? Do you regularly buy your coffee from a cafe? Why not ask them if they will consider TerraCycle? If you drink coffee from larger companies such as, Tassimo, L’OR and Kenco, there are (free) collection points for their packaging nationwide.

However, what if you don’t buy coffee from either Roasting House or Has Bean nor have easy access to a TerraCycle recycling box? There is one more option in the 3-r’s: re-use. To consider this question, I’ve been experimenting recently with a coffee bag with an air-valve (left over from Roasting House’s experiment that they were happy to send me, thanks Roasting House). Could the air valve be re-used as a valve for fermentation?

Lacto-Fermentation has been in the news a lot recently for the health benefits that it may have. However it is also an interesting and easy way of preserving almost any vegetable. The idea is simple. Mix the vegetables to be preserved in some salt water, store them in a jar and leave them for a few days. That’s it. The salt kills the harmful bacteria while allowing the bacteria that is good for us, the lactobacillus, to thrive. These lactobacillus also produce lactic acid that preserves the vegetables for many weeks while giving them that slightly sour taste of sauerkraut and kimchi.

lacto fermentation, airvalve, air valve, reduce reuse recycle
Can you use coffee bag air valves as one-way lids for fermenting vegetables?

A problem with fermentation seems to be that if you tightly seal the vegetables in a jar, the build up of gas during the fermentation process could mean that the mix explodes. If you open the jar every day to let the gas escape, you may well end up with mouldy cabbage rather than delightfully acidic sauerkraut. This is where the coffee bag air valve comes in. Could you replace the lid with a coffee air-valve and so allow the gas to escape while not having to open the lid every day?

Replacing the glass lid of a Kilner Jar with a lid made from a ring of cardboard (lined with the coffee packaging) and then the coffee bag with air valve seemed to work at first. As had been predicted, my first attempt at fermented spring greens (where I opened the lid each day) had resulted in mouldy cabbage. Successful fermentation came when the glass lid was replaced with the air-valve construction. Could there be a re-use for the air valve?

fermented cabbage
Fermented spring greens. These vegetables have been fermented with salt.

To check whether the valve worked as planned, I used it as a lid for a jar containing bicarbonate of soda and vinegar. As anyone who has played with these substances for making rockets or model volcanoes will know, combining these two substances produces a lot of gas. Again, nothing exploded. However, sadly (?) nothing exploded either when I sealed the air valve with sellotape and repeated the bicarbonate of soda/vinegar experiment. A quick inspection revealed air-gaps between the cardboard ring and the air valve lid and while these could be sealed quite easily, the air valve never seemed to be the primary outlet valve for this set-up.

So, a failure? A null result? Perhaps, but perhaps not. The air valve structure did mean that I was confident that I didn’t have to open the lid on the fermenting cabbage and the cabbage did not turn mouldy before it fermented. Unfortunately, it is hard for me to eat enough fermented cabbage to justify having repeated this experiment enough times yet to be certain! So this is where you come in. Why not have a go at making your own sauerkraut, kimchi or indeed any pickled vegetable (apart from potatoes apparently). Re-use that air valve while reducing food waste. If you do so, please do let me know your design and how it worked (and of course any good fermented vegetable recipes). Alternatively, if you have found another use for those old air valves, or know another coffee roasting company that is recycling its packaging or making efforts to move to  more sustainable packaging, please do let me know in the comment section below, on Twitter or on Facebook.

Enjoy your coffee and your lactobacillus.

*prices correct at time of writing (18th July 2017). Please check TerraCycle’s website for most recent prices. If you are outside the UK, the international website of TerraCycle can be found here.

Categories
General Sustainability/environmental Tea

Would you like plastic in that?

Straws with viscous liquid (milkshake) in them
Do you need that straw?

Plastic Free July starts in just a few days time. Each year this initiative encourages us to eliminate, or at least reduce, our use of single use plastic throughout the month of July. It is a great way to increase our awareness of our plastic use by attempting not to use any.

There are numerous reasons that we may want to reduce our plastic consumption. In addition to the problems of litter associated with plastic waste, there are problems for wildlife caused by ingesting our rubbish. Even if we dispose of it responsibly, plastic takes a long time to degrade. It is thought provoking to consider that the take-away cup that we discarded yesterday may still be lying in some landfill site years after we have forgotten about drinking that coffee. So what can be done about it and what are the specific issues for coffee drinkers?

air valve, plastic, environmental coffee packaging
Air valves and metallised plastic are common packaging materials for freshly roasted coffee, but can we avoid them?

One way to start to reduce our dependence on single use plastic is to understand how much we actually use on a day by day basis. Registering for a plastic free July is one way of doing this. As a result of attempting a Plastic Free July last year, I have found some plastic-free habits that have stuck with me all year. Loose leaf tea is one such improvement (teabags can also contain plastic). Although initially it seemed a bit of a pain to use a basket to brew the tea, as I kept with the habit I found it easy to compost the tea leaves after making a brew and the tea tastes better too. Things like shampoo bars and tooth ‘paste’ tablets (from Lush) have also been better and longer lasting than similar products packaged in plastic bottles.  Although some plastic habits are hard to break, living as plastic free as possible for one month did deepen my awareness of the plastic that I take for granted.

But perhaps living plastic free for a month is too daunting? An alternative challenge sadly emphasises just how linked coffee drinking can be to single-use plastic consumption. The Top 4 challenge asks you to eliminate, just for July, the target take-away items. Of these 4, at least 2 (and arguably 3) are linked to coffee drinking or cafés. The top 4 are plastic bags, bottles, take-away coffee cups and straws. Could you avoid these for just one month? Take the challenge.

blue tits, mint water, mint infusion, mint leaves in water
Enjoying a glass of water in a cafe can be better than running with a bottle of water anyway.

If you are ready to go plastic-free in your coffee habits, here’s a list of where we frequently encounter single-use plastic while drinking in cafés or even at home, together with suggestions of how to avoid the plastic where appropriate. Please let me know in the comments section below if you can think of further examples (and how you are avoiding them either in July or more permanently).

  • Disposable take-away coffee cups – get and use a re-usable one. You can find a helpful comparison of different types of re-usable coffee cups on Brian’s Coffee Spot.
  • Tea bags – yes they can contain plastic, see more information here. To avoid them, get hold of a metal tea basket, or even a tea pot and strainer and start investigating loose leaf tea.
  • Water bottles/soft drinks bottles – if in a café, why not enjoy the moment by staying with a glass of water rather than grabbing a bottle? If you are in a hurry though, a flask (such as klean-kanteen) is a great investment. In some parts of London (and perhaps elsewhere?) chilled tap water is available on tap for use in re-usable bottles
  • Air valves on your roasted coffee bag – do you really need these? The Nottingham based coffee roaster, Roasting House, did a taste test on freshly roasted coffee packaged with and without air valves, you can read their results here. If the coffee roaster that you normally purchase coffee from insists on using air-valves, why not write to them to request that they reconsider their packaging or try a more environmentally conscious roasting company to see how their coffee compares?
  • Coffee packaging – What type of material did the last bag of coffee that you purchased come in? Chances are it was metallised plastic, why not find a roaster with alternative packaging? Who knows, you may find another great coffee roaster to add to the ones that you buy from.
  • Straws – why would you use these anyway?
  • Milk bottles – Some companies still supply milk in glass bottles, otherwise you could consider non-dairy milks that can be home-made such as oat or almond. Some cafés also offer home-made non-dairy milks which would be a way of going plastic free while enjoying a latte in a café.
  • Cakes/sandwiches packaging – in larger chains these may come in packaging. However, if they are coming in packaging then they are not likely to be that fresh, find somewhere else with better cakes or sandwiches or make your own!
  • Spoons/cutlery
  • Packaging for sugar etc – ditching the sugar is supposed to be good for you anyway. If you cannot resist sweetening your coffee, try to find a sugar that is packaged in paper rather than plastic.
  • Washing up liquid – switching to a re-fillable washing up liquid reduces (but does not eliminate entirely) plastic waste.

Good luck if you take the challenge. There are still a few days left to plan how you can reduce the plastic in your life before the start of Plastic Free July 2017. Please do let me know how your attempts to be plastic free go and whether you find, as I did last year, that you enjoy your tea (or even coffee) more when you do so.

 

 

Categories
Coffee cup science Observations Sustainability/environmental

Stirring up some climate science

Everything is connected. At least, that is part of the premise of Bean Thinking, where the physics of a coffee cup is used to explore the physics of the wider world. So it was great to stumble upon a new connection that I had not previously appreciated¹.

vortices in coffee
Like the vortices behind a spoon dragged through coffee….

The connection is between climate science and that wonderful pastime of pulling a spoon through coffee and watching the vortices form behind it. Yet the research that revealed this connection was not looking for links between coffee and the atmosphere. Instead the researchers were interested in something seemingly (and hopefully) very far from a coffee cup: rogue waves.

Rogue waves are rare and extremely large waves that have been the subject of mariners tales for many years. Nonetheless, it is only relatively recently that they have become the subject of scientific research, partly because they are so rare and so outside our usual experience that they were thought to be the stuff of myth rather than of science. So it is only now that we are developing an understanding of how it can be that, in amongst a number of smaller waves, a massive wave of 20m height can suddenly appear, apparently out of nowhere. One of the groups looking at this problem investigated the effect of a particular sort of (known) instability on a series of waves in water. However, unlike other research groups, this particular study included the effect of the air above the water as well as the waves themselves.

Small waves seen from Lindisfarne
Rogue waves seem to come out of nowhere. A rogue wave can be 2 or 3 times the height of the other waves in the water at the time. How and why do they form?

Although this sounds a simple idea, modelling water waves in air is actually extremely complex. To do so, the authors of the study had to use a computer simulation of the air-water interface. It is not the sort of problem that can be solved analytically, instead the computer has to crunch through the numerical solutions. In order to start to see what was going on with the rogue waves, the authors had to simulate multiple waves of different amplitudes. Each simulation took weeks to perform. Given that this was only a few years ago (the study was published in 2013), you can start to see why people had previously been approximating water waves as waves in water (without worrying too much about the air interface).

Now here is where the link with coffee comes in. The group modelled waves as a function of steepness and found that, above a critical steepness, the wave breaking caused significant interaction between the air and the water layers. In addition to the bubbles that form when waves break, the movement of the air over the breaking wave formed into a vortex which, when it interacted with the back of the wave created an opposite vortex: a vortex dipole “much like the vortices that form behind a spoon dragged through a cup of coffee“.

Rayleigh Benard cells in clouds
The water droplets that form clouds are often ‘seeded’ by particles of salt or dust, such as the aerosols distributed by the vortices in this wave study. Image shows clouds above the Pacific. Image NASA image by Jeff Schmaltz, LANCE/EOSDIS Rapid Response

Just as with the vortices in the coffee cup, vortices were forming in the air behind the wave crest (which acted as the spoon) and travelled upwards through the atmosphere and away from the waves. As each wave broke, a train of vortex dipoles were produced that twirled off into the sky. Imagine a coffee bath and multiple spoons rather than a coffee cup. The authors suggested that these vortices could carry aerosols from the sea (salt, water droplets etc) into the atmosphere. Travelling within the vortices, these tiny particles could travel far further and far higher than we may have expected otherwise. Such aerosols can be critical for cloud formation and so the effect of these breaking waves could be important for climate modelling.

While an undergraduate, I had an opportunity to study a course in atmospheric physics. I remember the lecturer lamenting that while we (as a community, but not really as the students sitting in the lecture theatre at that time) understood atmospheric modelling quite well and that we understood how to model the oceans fairly well, we got problems when we tried to put the two sets of models together. It was clear that something wasn’t quite right. Years later, it seems that at least past of the reason for that is linked to those vortices that you see as you pull your spoon through your coffee cup.

Everything is connected indeed.

A summary of the study can be found here. The abstract (and link to the pdf) of the published paper can be found here. If you do not have access to the journal through a library, an early, but free, version of the paper is here – note though that this version may not include the amendments included after peer review.

 

¹A quote attributed to Jean-Baptiste Biot (1774-1862), is perhaps relevant here “Nothing is so easy to see than what has been found yesterday, and nothing more difficult than what will be found tomorrow.”