Sustainability/environmental

A post in need of a Curator(s) Coffee, Fitzrovia

espresso Curators

A deliciously intense and fruity espresso from the ‘specials’ menu at Curators Coffee.

Curators Coffee in Margaret St in Fitzrovia has been there for years. A great location just off of Oxford St, with plenty of seating and good coffee, and so it is perfect to pop into, unless you are like me and avoid the Oxford St area as much as possible. Which perhaps explains the rarity of my visits. I first popped into Curators Coffee a couple of years back (before the laws on allergen information came in) when I remember enjoying a lovely long black but couldn’t have a cake because the people behind the counter that day couldn’t tell me which (if any) cakes contained nuts. At the time, I sat upstairs and noticed the graphene type arrangement of hexagons around the back of the space and the Bramah’s 300 years of coffee makers book in a rack at the back. I had wanted to return to properly cafe-physics review the place at a later date (and try the cake) but circumstances (and Oxford St avoidance) meant that I never got round to it. Until very recently.

This time, I noticed that there were three single origin coffees available to try as espresso. Glancing at the tasting notes it was a fairly quick decision: “chocolate”. And although this time I had just had lunch and so passed on the cake, it appears that the espresso choices regularly rotate, offering an incentive to come back again and try something new. Although the café is quite large, with plenty of seating, it seems that it is also very popular. And so there were no spaces remaining upstairs. Fortunately, there were more seats downstairs and so, taking our table number with us, we made our way down the stairs and found a table at the window, as if it was waiting for us.

UFO in Curators Coffee Fitzrovia

A UFO reflected in the window? Why? What? Why (again)? It is small details such as this that reward you as you put down your smart phone and notice your surroundings.

Perhaps it is obvious that a café called Curators should have art work adorning the walls. That, and the spotlights that highlighted the work immediately caught our interest, (although it was odd to see that one of the rows of spotlights was almost devoid of bulbs). The exhibition downstairs seemed to have a tilt towards street art and a couple of decorated aerosol cans were on the windowsill priced at £15 each. Was this the time to consider why an aerosol gets cooler as you spray the walls with it?

Outside the window, a staircase leading up to the street outside had railings in straight lines leading up towards a blue sky. Inside, a space craft was reflected in the window.

Indeed, on checking again, there was a spacecraft, like a cartoon of a stereotypical little UFO, drawn onto the wall behind my accomplice’s head and reflected in the window next to it. What could it mean? Regardless of whether some UFO incidents are associated with visitors from other planets, there are a large number of scientific thought trains we can take when considering a UFO reflected in a window. To start with, how likely is it that we are alone in the universe or that there are many other intelligent life forms in other planetary systems?

The question has been answered on the basis of probability for many years. But recently, we have been finding more planets orbiting stars and crucially, more planets that are in the ‘habitable’ zone around other stars. Assuming that life elsewhere needs similar conditions to the earth’s in order to thrive, the idea of life elsewhere is becoming increasingly real.

canali Curators Coffee

If you see straight lines such as this, it is fairly sensible to infer that they were built by an intelligent life-form. Can you see canals on Mars?

Closer to home, there were even suggestions that Mars may support flowing water, thought to be a host for bacteria based life. And although these interpretations of the flow patterns observed on the Martian surface have more recently been contested (could they instead be flowing sand?), we continue to send probes (such as the Insight probe that landed recently) to the red planet to investigate its geology. Did Mars once host life?  Mars of course has a resonance in science fiction for being the planet hosting extra-terrestrial life. HG Wells imagined the Martians landing just south of London, and eventually being killed off by exposure to bacteria on earth that they had not experienced in their Martian habitat. Could life on Mars suggest a (tenuous) further link to this café on Margaret St?

Perhaps one reason that people started to imagine (intelligent) life on Mars came about because of an interesting mistranslation of an astronomical observation. While gazing at Mars in 1877, Schiaparelli noted ‘canali’ on the Martian surface. The correct translation of this in this context into English is “channels” but what the observation came to be known as was “canals”. Canals imply an intelligent builder, and hence life on Mars. Later observers also saw these ‘canals’ and a popular myth was born. It is a useful lesson for us all, sometimes how we see something can be influenced by the language we use to describe it.

soya hot chocolate, Curators

We photograph our coffee, and share it with our online friends. But would putting down our phone in a cafe be worth something for the planet as well as for ourselves? How many batteries do we need?

And then one final thought train, prompted by photographing the cafe with my mobile phone. The whole probability argument rests on two assumptions. The first is that there are other planetary systems (which we are finding). The second is that life is fairly easy to start, or at least, that the chances of producing life are not restricted to one planet a short distance away from the Sun; we are not unique. As yet we don’t know whether this assumption is justified but discoveries such as the deep sea hydrothermal vents challenge our preconceptions about the requirements for life and suggest that life could start more than once, and so could very well start on other planets, not just ours. In these vents, bacteria are known to convert what we think of as toxic chemicals into energy in a process known as chemosynthesis without the need of sunlight or other ingredients that we had thought essential to life. Could similar hydrothermal vents on other planets host new life forms?

And in a related way, what is going on with these vents? Is new life being created even now in the deep sea? In which case, what do we think about deep sea mining? If our aim is to reduce our carbon dioxide emissions by using more re-usable objects and renewable energy sources, we will require more batteries and batteries require (among other things) cobalt. If we are all to keep using mobile phones to photograph cafés, we too need the batteries which rely on these elements. A number of companies have realised that there is a vast untapped resource under the sea if only we could dredge it up. This may be easier or ultimately cheaper than recycling the old batteries. It may destroy a few hydrothermal vents or stir up the sea bed but what concern is that to us if we can gain access to more cobalt to allow us to have more batteries to allow us to all be ‘greener’.

Indeed, of what concern is that to us?

Curators Coffee is at 51 Margaret St, W1W 8SG

A Story with many layers, Clapham Junction

Story Coffee St John's Hill Clapham

The doorway to Story, or a story depending on how you look at it.

A “ghost sign” above the door to Story Coffee on St John’s Hill ensures that you know that you have arrived at the correct place. “Peterkin Custard, Self-Raising Flour – Corn Flour, can be obtained here”, only now it is coffee rather than custard that is sold in the shop beneath. The sign is an indicator to the many tales that could be discerned while exploring the coffee within. I had had a couple of attempts to visit Story Coffee (thwarted for a variety of reasons) before Brian’s Coffee Spot’s review appeared a couple of days after one of my attempted visits. Suitably re-motivated, another trip was attempted (address checked, closing times checked) and this time we were in luck. Although a pour over is listed on the menu, sadly this was not available on our visit and so I enjoyed a lovely long black instead (Red Brick, Square Mile) while looking at the cakes on offer. There was plenty of seating in which to shelter from the rain outside and many things to notice in this friendly café. In addition to the cakes and lunch menu, a box on the counter housed “eat grub” protein bars, protein bars made of cricket powder. Are insects the future for humans to eat protein sustainably?

glass jar at Story

Through a glass darkly?
The distortions produced by the refractive indices of air, water and glass and the shape of the glass produces interesting effects on our view through it.

The tables were well arranged for people to sit chatting while enjoying their beverages and it is always an excellent thing (from a personal point of view) to encounter a café with a no laptop (or tablet) at the tables policy. Complementary tap water was available in jugs placed on each table while it was also nice to note that Story branded re-usable cups were on sale from the counter. Many things we noted can be seen in the gallery pictures in the review on Brian’s Coffee Spot: the funky fans, the egg shaped light shades, the light introduced by the large glass window panes (though it was a much fairer day on Brian’s visit than on ours). Each had its contribution to a thought train, the way the glass water jar bent the light coming through, the concept of a Prandtl boundary layer in fluids (and its connection to both fans and coffee cups). Moreover there were hexagons, which for someone who has worked on the periphery of the graphene craze, are always thought provoking.

Apart from hexagons decorating the top of the stools, there were hexagons lining the counter made of cut logs, each showing the rings from the tree that was felled. Rather than a flat surface, these hexagons were made to be different thicknesses on the wall, rather like the hexagonal columns of the Giant’s Causeway. It is a subtle thing that may have implications for the space that is otherwise surrounded by flat, solid, walls. Such spaces can become echo-y and yet, the music and conversation in Story was not overly distracting presumably because features such as the uneven hexagonal wall reflected the sound waves such that they destructively interfered rather than echoed around the room.

every tree tells a story, but which story

A macroscopic crystal of hexagonally cut logs forms the side of the counter.

Each log in the hexagonal decoration was cut with its cross-section showing a number of tree rings. We know that we can age a tree by counting the rings (though each of these would be underestimated as they have been trimmed into hexagons post-drying), but what more do the tree rings, and the trees themselves have to tell us? The rings are caused by the rapid growth of large cells during spring followed by a slower growth of smaller cells as the year progresses. But this method of growth means that the cut logs have more to tell us than just their age. The spacing between the rings can tell of the weather the tree experienced during that year, were there many years of drought for example? Such clues, from the relative density of the tree rings, can help researchers learn about the climate in previous centuries, but conversely, reading the climate report in the rings can indicate in which year a tree was felled and so the age of a building for example.

coffee at Story

Many stories start with a coffee.

And then there is more, trees will grow at an average rate per year so that, as a rough guide, the circumference of a mature (but not old) tree increases by 2.5cm per year¹. There is therefore something in the idea that you can have a good guess at how old a tree is by hugging it. But this assumes that the tree is growing in its optimum conditions, far enough from any neighbouring trees so as not to be crowded into growing more slowly. So the absolute density of tree rings must also give a clue as to whether this tree was in a dense forest or an open clearing. Which is reminiscent of something else that living trees can tell you if you listen to them closely enough: trees will grow so that their leaves are exposed to the maximum amount of light. For us in the UK, this means that the crown of a tree will frequently tip towards the south (where the Sun is most often) and there will be more leaf growth (and consequently more branches) in a southerly direction². But again, we only see this if the tree has room to grow on its own, without the crowding, and competition, of too many neighbours. A solitary tree helps us to know which direction we are walking in.

empty coffee cup Story St John's Hill

While many coffees could also tell a story. It depends on how you read them.

Which all points to the idea that there are many stories being told all around us all of the time, the ones we hear depend on what we choose to pay attention to. So what about the story behind the ghost sign above the door? The Peterkin custard company was a venture by J. Arthur Rank in an attempt to start a milling company in the mould of his father’s (Rank Hovis McDougall, later bought by Premier Foods). The company failed and Rank went on to form the Rank Organisation that was responsible for many films made throughout the 40s and 50s as well as running a chain of cinemas around the UK. Truly a sign concealing many stories.

 

Story Coffee is at 115 St John’s Hill, SW11 1SZ

¹Collins complete guide to British Trees, Collins, 2007

²The Walker’s Guide to Outdoor Clues and Signs, Tristan Gooley, Hodder and Stoughton, 2014

 

 

 

 

Air raising

Small waves seen from Lindisfarne

How do clouds form? How does temperature vary with altitude, and what does coffee have to do with any of it?

You put a drop of alcohol on your hand and feel your hand get cooler as the alcohol evaporates, but what has this to do with coffee, climate and physics?

Erasmus Darwin (1731-1802) was the grandfather of Charles of “Origin of the Species” fame. As a member of the Lunar Society (so-called because the members used to meet on evenings on which there was a full moon so that they could continue their discussions into the night and still see their way home) he would conduct all sorts of scientific experiments and propose various imaginative inventions. Other members of the Lunar Society included Matthew Boulton, Josiah Wedgwood and Joseph Priestley. The society was a great example of what can happen when a group of people who are interested in how things work get together and investigate things, partly just for the sake of it.

One of the things that Darwin had noticed was that when ether* evaporates from your hand, it cools it down, just as alcohol does. Darwin considered that in order to evaporate, the ether (or alcohol or even water) needed the heat that was provided by his hand, hence his hand started to feel cooler. But then he considered the corollary, if water (ether or alcohol) were to condense, would it not give off heat? He started to form an explanation of how clouds form: As moist air rises, it cools and expands until the moisture in the air starts to condense into droplets, clouds.

hole in water alcohol

There are several cool things you can notice with evaporating alcohol. Here a hole has been created in a thin layer of coffee by evaporating some gin. You can see the video of the effect here.

As with many such ideas, we can do a ‘back of the envelope’ calculation to see if Darwin could be correct, which is where we could also bring in coffee. The arabica growing regions are in the “bean belt” between 25 °N and 30 °S. In the sub-tropical region of that belt, between about 16-24°, the arabica is best grown at an altitude between 550-1100 m (1800-3600 ft). In the more equatorial regions (< 10º), the arabica is grown between 1100-1920m (3600-6300 ft). It makes sense that in the hotter, equatorial regions, the arabica needs to be grown at higher altitude so that the air is cooler, but can we calculate how much cooler it should be and then compare to how much cooler it is?

We do this by assuming that we can define a parcel of air that we will allow to rise (in our rough calculation of what is going on)¹. We assume that the parcel stays intact as it rises but that its temperature and pressure can vary as they would for an ideal gas. Assuming that the air parcel does not encounter friction as it rises (so we have a reversible process), what we are left with is that the rate of change of temperature with height (dT/dz) is given by the ratio of the gravitational acceleration (g) to the specific heat of the air at constant pressure (Cp) or, to express it mathematically:

dT/dz = -g/Cp = Γa

Γa is known as the adiabatic lapse rate and because it only depends on the gravitational acceleration and the specific heat of the gas at constant pressure (which we know/can measure), we can calculate it exactly. For dry air, the rate of change of temperature with height for an air parcel is -9.8 Kelvin/Km.

contrail, sunset

Contrails are caused by condensing water droplets behind aeroplanes.

So, a difference in mountain height of 1000 m would lead to a temperature drop of 9.8 ºC. Does this explain why coffee grows in the hills of Mexico at around 1000 m but the mountains of Columbia at around 1900 m? Not really. If you take the mountains of Columbia as an example, the average temperature at 1000 m is about 24ºC all year, but climb to 2000 m and the temperature only drops to 17-22ºC. How can we reconcile this with our calculation?

Firstly of course we have not considered microclimate and the heating effects of the sides or plateaus of the mountains together with the local weather patterns that will form in different regions of the world. But we have also missed something slightly more fundamental in our calculation, and something that will take us back to Erasmus Darwin: the air is not dry.

Specific heat is the amount of energy that is required to increase the temperature of a substance by one degree. Dry air has a different specific heat to that of air containing water vapour and so the adiabatic lapse rate (g/Cp) will be different. Additionally however we have Erasmus Darwin’s deduction from his ether: water vapour that condenses into water droplets will release heat. Condensing water vapour out of moist air will therefore affect the adiabatic lapse rate and, because there are now droplets of water in our air parcel, there will be clouds. When we calculate the temperature variation with height for water-saturated air, it is as low as 0.5 ºC/100 m (or 5 K/Km), more in keeping with the variations that we observe in the coffee growing regions†.

We have gone from having our head in the clouds and arrived back at our observations of evaporating liquids. It is fascinating what Erasmus Darwin was able to deduce about the way the world worked from what he noticed in his every-day life. Ideas that he could then either calculate, or experiment with to test. We have very varied lives and very varied approaches to coffee brewing. What will you notice? What will you deduce? How can you test it?

 

*ether could refer to a number of chemicals but given that Erasmus Darwin was a medical doctor, is it possible that the ether he refers to was the ether that is used as an anaesthetic?

†Though actually we still haven’t accounted for microclimate/weather patterns and so it is still very much a ‘rough’ calculation. The calculation would be far better tested by using weather balloons etc. as indeed it has been.

¹The calculation can be found in “Introduction to Atmospheric Physics”, David Andrews, Cambridge University Press

 

 

Time out

Perhaps an unusual post but there is so much opportunity to stop, think and notice at the moment. Whether it is relaxing in a café with a cold brew or sipping a take-away in a park. There is time to slow down and ponder. Here are three points that have been puzzling recently. What do you think? Perhaps you have other things that you ponder while sitting in a café? Let me know either in the comments section below, on twitter or on Facebook.

oat milk, kone, filtering

Oat milk filtering through the Kone filter – but what does oat milk tell us about Brownian motion, molecular ‘reality’ and the nature of a scientific theory?

Molecules, the atmosphere and oat milk.

On pouring home-made oat milk into a cup of black tea, it is noticeable that a large part of the oat milk is dense and falls to the bottom of the cup (before being stirred by the turbulence in the tea). A similar phenomenon is found in the rarefaction of gases through the height of the atmosphere and in the distribution of dye in water paint. This latter effect was used to establish the existence of molecules back in 1910. The idea that Brownian motion was caused by molecules had been problematic because there was no way to see molecules in a liquid producing the Brownian motion. The theory linking the two was only developed properly in the early twentieth century. What makes a scientific theory? Is it legitimate to postulate something that cannot currently be observed experimentally?

Packing value

Why does roasted coffee often come in plastic packaging that is unrecyclable and not very reusable? What could prompt a move to a more circular economy. Would it be possible to recycle plastic bottles into coffee ‘boxes’ with an air valve at the bottle top (see pictures). This would increase the recyclability without seeming to affect the taste of the coffee?

bottle, coffee bottle, coffee box, coffee packaging

An idea for a circular economy suitable coffee packaging? Recycled plastic bottles as airtight coffee containers.

Related to that, what are your coffee values? Do you favour taste and aroma, traceability, sustainability? Does the packaging that your coffee arrives in feature? Which of these is more important to you? Does the way you drink coffee reflect this?

Footfall past a café

How many people are walking past the café you are sitting in each minute? How many does that translate to per day (accounting for differences in day/night footfall)? Assuming the paving stones remain the same, how long would it be until the successive footprints of all these people caused erosion of the pavement surface? What are the implications of this for the geological features near you?

Whatever you think about in a café or while drinking a coffee, enjoy your time taken out to think. Perhaps you will notice something (or realise something) very interesting or noteworthy and if you have any thoughts on any of the above do let me know either in the comments, on Twitter or on Facebook.

 

Bee-ing positive at the Sugar Pot, Kennington

coffee and cake Kennington

Banana bread and coffee with a sugar pot in the background at Sugar Pot, Kennington

What is it that makes a great café? A space to slow down and think? Good coffee and cakes? A local business that forms part of its local community and gives back to that community in different ways? As I was looking around for a new café to try, I was reminded of Sugar Pot in Kennington. Their website suggested that it ticked all of these boxes and so I was eager to try it (so eager in fact that I didn’t note the opening times, they close at 3 on week-days which is a problem when you arrive at about 2.55). So a second attempt at trying Sugar Pot was arranged, this time safely before lunch. This time, in the morning, there were quite a few chairs and tables outside the café in a roped off area of the street. (We hadn’t noticed this on the first occasion we visited as they had all been piled up inside the shop by the time we arrived). Most of these tables were occupied indicating that it is clearly an attractive place for locals to meet and chat over coffee. Fortunately there were also a fair number of tables inside which suited us as a café often offers more to ponder inside than out (though outside offers a different perspective particularly for people watching).

Inside, each table has an individual character and one in particular offered several points to think about both in terms of physics and aesthetics (you will have to visit to understand). However, it was elsewhere that my attention was drawn that day. Coffee is roasted locally by Cable Bakery while the cakes are from John the Baker of the Kennington Bakery. Sugar Pot definitely gets a tick in the “allergy friendly” box because they answered confidently (and with required caveats about traces) my dreaded question “does it contain nuts?” So I was able to enjoy a lovely slice of banana bread with my coffee. Most of the usual espresso based drinks are available (but not listed on the menu) together with a French Press coffee for those who prefer a non-espresso brew.

Interior Sugar Pot, Kennington

Noticeboard, magazines and coffee counter at Sugar Pot in Kennington

The community feel of the café was immediately apparent with a notice board adjacent to the counter being packed with notices of different activities happening around the locality and within Kennington Park which is just opposite. Underneath the counter were books and magazines and an advert for volunteering with the local bee keeping and urban farming organisation Bee Urban. This is indeed another way that Sugar pot gets involved in its local community. The coffee grounds are donated to Bee Urban for use in their Kennington Park based composting facility. Bees of course have an Albert Einstein link with physics as he is alleged to have said

“If the bee disappeared off the surface of the globe, then man would have only four years of life left. No more bees, no more pollinators, no more plants, no more animals, no more man.”

I do not know if he really did say this but it is a sad reflection on our society that rather than address our environmental crimes we are researching pollinating with drones. However, it turns out the the bee has a much more exciting, almost shocking, link with physics and one that I only discovered thanks to the excellent book “Storm in a Teacup” by Helen Czerski¹. The bee is indeed a very positive creature.

ultra violet, bee, bumble bee

The world looks very different to a bee. Image © www.gardensafari.net

Whether or not they have a happy disposition, it seems that 94% of bees are, electrically speaking, positively charged². They pick up a static charge while flying through the air in a similar way to a balloon being rubbed on your hair. Flowers meanwhile have a negative charge meaning that in addition to colour, shape, scent and pattern, bees can recognise flowers by their electric fields. These fields in turn mean that pollen from the flower ‘jumps off’ and adheres to the bees fur before the bee has even landed, increasing the efficiency of the bee as a pollinator. But it turns out that there is much more to it. When the positive bee lands on the negative flower, there is a charge transfer that results in a change of the electric field around the flower for a duration of 100 seconds or so. By constructing artificial flowers held at different voltages containing either a sugar reward or a bitter centre, researchers at Bristol university found that bees could learn to recognise which ‘flowers’ contained the sugar and which were too bitter to be visited by sensing the electric field around the ‘flower’. It suggests that the changing electric field of real flowers provides a mechanism by which the bee can recognise if a flower has been recently visited by another bee and so been recently pollenated. This would mean that by ‘feeling’ the electric field of the flower, the bee may decide that it would be more rewarding to carry on to a differently charged flower. You can read more about the research in the paper here.

It seems to me that learning about how the bee senses its environment reveals even more about the amazing way that nature (and physics) works. And this offers a link back to Sugar Pot. On the shelf behind the counter back at Sugar Pot was a card that had the message “Keep safe, live to be”. What does it mean “live to be”? In the environmental encyclical Laudato Si’, Pope Francis urges everyone to slow down and notice things such as the bee commenting that “If someone has not learned to stop and admire something beautiful, we should not be surprised if he or she treats everything as an object to be used and abused without scruple.” He goes on “… when media and the digital world become omnipresent, their influence can stop people from learning how to live wisely, to think deeply and to love generously… True wisdom, as the fruit of self-examination, dialogue and generous encounter between persons, is not acquired by a mere accumulation of data...”³ Which is one reason that in order to be, we may want to come back and take a closer look at those bees. Taking time to experience our coffee in a relaxing space such as Sugar Pot and to watch and ponder as the bee uses senses of which we are barely aware can never be a waste of our time. Indeed, it is possible that our world may depend on it.

¹Storm in a Teacup, Helen Czerski, Transworld Publishers, 2016

² Clarke et al., “Detection and learning of Floral Electric Fields by Bumblebees”, Science, 340, 6128, 66 (2013).

³The passages quoted are from paragraphs 215 and 225 respectively of Laudato Si which can be read online.

Sugar Pot can be found at 248 Kennington Park Road, SE11 4DA

Half way through…

talesfromthewormbin

What packaging does your coffee come in? Is it paper, compostable? The bits of packaging here are part of an experiment to see how long they will take to break down in a worm composting bin #talesfromthewormbin

The problem is oat milk. If you are having a go at living plastic free (or even reducing your reliance on single use plastic) during Plastic Free July, you have probably encountered at least one sticking point. Something that you are finding a little tricky to let go of. There are things that are too difficult to eliminate right now (meat/fish packaging is one example although there have been efforts to change this in some locations) but these are not necessarily sticking points. No, sticking points are things that seem that they should be easy to eliminate but for some reason are not. For me this is oat milk.

For the past three years, I have been participating in Plastic Free July with the aim of trying to find ways of living that reduce my plastic waste. And for the past three years, the problem has been oat milk. It is becoming a bit of a nemesis. Although proper, dairy based milk is available in glass bottles, this does not appear true for non-dairy based milks. Although some packaging can be recycled, it is a significant contributor to my waste pile. So, how about home made oat milk? It should be easy shouldn’t it?

oat milk, kone, filtering

Oat milk filtering through the Kone filter.

You can find plenty of recipes for oat milk online (a few are here, here and here) but I’ve always found it messy and, well, wasteful. The worms have enjoyed the oats in the past but surely there’s something better that can be done with them? Well, this year, things seem a bit different. And part of that is because of a coffee filter.

Years ago I tried the coffee Kone filter as an attempt to reduce my use of paper filters in the chemex. Sadly, I didn’t get on with the Kone. Unlike a paper filter, some sediment made it through the filter leading to more of an immersion type coffee drink rather than a filter. Consequently it went to the top of a cupboard and lay forgotten for a few years. Until this June when I re-discovered it as a filter for the oat milk. Rather than a muslin bag, the Kone can be cleaned easily and the whole process is significantly less messy (and slightly quicker – stirring the contents of the Kone with a spoon is easier encouragement to get the oat milk through than squeezing the muslin bag). Although there remains significant work before this can start to be a habit rather than just for a month, this July’s oat milk is a lot more promising than previous years. I’ll keep you updated as to whether the oat milk remains being home made in August.

pitch drop oat milk

Preparing your own dairy-free milk also offers new opportunities for watching physics such as the pitch-drop experiment here.

In the meantime, do let me know how you are getting on with your own Plastic Free July. Do you have any sticking points? On the other hand, are you finding that you are enjoying taking your re-usable cup around with you when you get a take-out coffee? Also, if you have any recipes for things that can be done with these left over blended oats. I’d love to hear of your culinary experiments.

In the following recipes, because I do not know how much oat milk you are making, I’ll call the amount of blended oats X g. In my experiments X has been either 115g or ~60g.

 

Oat and Apple Tarts

Xg blended oat left overs

Xg sugar

X/2 g flour

Pinch cinnamon and nutmeg to taste

teaspoon baking powder

Cooking apple (peeled and cut into smallish chunks)

 

Mix the blended oat left overs with the sugar and then stir in the flour, baking powder and spices. Spoon onto a greased baking sheet so that they make circular blobs of about 3cm diameter. Place the apple pieces into the mixture and bake at 180C for about 15 minutes until risen and slightly browned.

 

Sort of Flapjacks

X g blended oat left overs

X g sugar

X/2 g flour (but this isn’t really necessary).

Oat flakes, spelt flakes, sunflower seeds, pumpkin seeds, dried fruit, whatever you would like to put in a flapjack

Mix everything together, spoon into a lined and greased baking tin, bake at 190C for 15 minutes until firm. Keeps in an airtight container for days.

 

Hobnobby biscuits

home made oat biscuits

Not quite there yet. If you have a better recipe or can improve this one, please let me know.

A work in progress – the quantity of oats is not right yet and perhaps they need to be toasted oats or even spelt flakes.

X g blended oat left overs

X g sugar

X/2 g flour

teaspoon baking powder.

X-2X g oats

Mix the blended left overs, sugar, flour and baking powder together. Stir in the oats. Spoon on a lined and greased baking sheet so that you get ‘biscuit sized’ portions. Bake for 25 minutes at 190C or until brown.

 

Creating movement at Kahaila, Brick Lane

coffee Brick Lane, against trafficking, women's project, charity

Kahaila on Brick Lane. A small shop front concealing a large interior.

It’s always great to find an independent café selling good coffee (and cake) while giving something back to the community. It’s a reason to seek out small businesses rather than chains. Kahaila café on Brick Lane absolutely falls into this category. Although I had visited Kahaila previously, on that occasion the beigels (almost) next door were ‘calling’ and I did not give this space the time it deserved. This time however, the beigel shop had come first allowing us plenty of time to sit and ponder in this spacious café.

I had an espresso (toffee notes) together with a raspberry topped vegan chocolate cake (confidently nut free). There were a large variety of alternative cakes on offer at the counter along with cold drinks should you want them in summer. The espresso was a very enjoyable accompaniment to the cake (or should the cake be an accompaniment to the coffee?). The large room at the back of the café offered plenty of seating and was well lit by sunlight streaming through a window built into the roof.

coffee cake, Kahaila, Brick Lane

Raspberry vegan chocolate cake with espresso. The blue cup can affect the way the coffee is experienced.

One thing that immediately makes this café different from many others, is the fact that there is a donation box on the wall. Information cards on the table tops explain that Kahaila works as a charity providing education and support to women prisoners, helping women who have experienced abuse or are vulnerable in other ways to learn skills in a bakery and also offering a safe house for women who have been victim to exploitation and trafficking. All in all a café in which it would be good to spend more time (if only it were closer!). And assuming that the cakes are from the bakery, it forms a giving-circle with some great bakes on offer.

The vegan chocolate cake was a case in point. Beautifully presented, balanced in taste, in a perfectly sized portion to enjoy with a coffee. Ordinarily cakes require butter and eggs, how did the bakers manage it? Of course, a recipe was not given at the counter, nor would it necessarily have been particularly helpful to answer the question. Because the answer, if one exists, is a mix of their experimentation with flavours and textures together with an advancing knowledge of what each cake ingredient does.

sugar in a jar, Kahaila

The way these sugar cubes stacked in the jar and the sugar granules at the bottom reminded me of something. I was not able to put my finger on what it was…

Consider the egg yolk. In addition to adding mouth feel and texture to the cake or biscuit, the yolk contains emulsifying agents, such as lecithin, which act to stabilise suspensions of oil in water¹. With a hydrophobic section at one end of the molecule and a hydrophilic section elsewhere, the presence of lecithin molecules in the mixture prevents droplets of oil from grouping together and coalescing so as to separate into oil/water layers. By experimenting with non-egg based lecithin, a baker can combine different flavours and textures to produce a vegan cake.

A few years ago, a somewhat similar problem was vexing materials scientists: how to remove toxic lead from piezoelectric devices. Piezoelectric devices expand or contract when they are subjected to an electric field. This makes them useful for moving mechanisms such as watches and even as a way to open/close hot water valves in coffee machines. The problem was that one of the best piezoelectric materials we had was lead zirconate titanate (or PZT for short). In order to make the PZT material, the lead had to be sourced in quite large quantities and yet, being toxic and environmentally damaging, it was considered advantageous (even necessary) to remove the lead.

doorway in Kahaila

A painted doorway inside Kahaila in combination with flowers in front suggests a thought train about the way bees see.

However, just like the egg yolk in cookie recipes, you cannot just remove it and produce the same sort of effect in the finished product. You need to understand what role the lead was playing in order to be able to substitute it properly and even then, the effect may not be as good as the original ingredient (without some tweaking elsewhere in the recipe also). Consequently a lot of research has been undertaken in order to find new piezoelectric materials and to understand them so as to optimise the piezoelectric effect. Partly this involves adding the new ingredients slowly to understand their role. Partly it involves changing the growth conditions (somewhat equivalent to the baking temperature) in the crystals that are made. Always it involves experimenting and understanding the role that different ingredients play in our final devices.

Research is still ongoing to find a good substitute for lead in piezoelectric devices. But it goes to show that there are many connections between diverse areas of our experience. Unlike research into piezoelectric materials though, the advantage in experimenting with cakes is that the test of the result is in the eating. Now to experiment with some biscuit recipes…

Kahaila is at 135 Brick Lane, E1 6SB

¹On Food and Cooking, the science and lore of the kitchen, Harold McGee

 

 

 

Paradigm shifts at The Observatory, Marchmont St

lines on a table, parallax

An espresso using coffee from Redemption Roasters and a chocolate brownie. What more could you ask?

Many years ago, there was an aquatics shop on the site of what is now The Observatory, a combined photography gallery and coffee shop. Although there is plenty to see through this glass fronted café, you do not feel that you are in a goldfish bowl so much as that this is a space created for you to slow down and contemplate your surroundings. The large rooms and comfortably spaced tables do, of course, give the opportunity for people watching: when we visited, there were people working with their laptops on some tables while others were having business meetings. Then there are the photographs, currently (though only for a few more days), an exhibition of photographs from the 60s and 70s by John Bulmer.

The coffee is supplied by Redemption Roasters and I enjoyed a dark, toffee like espresso with a very good slice of a chocolate brownie (confidently nut free). Several types of milk are on offer for milk based coffee drinks as well as a selection of cold drinks, together with a wide variety of cakes. It is definitely a place to return to when in the area.

coffee the Observatory, TLR

Cakes on the counter at The Observatory. Note the twin lens reflex “camera” on the shelf behind the counter.

While waiting for my coffee, I noticed the grain of the wood in the table. Dark, almost parallel lines on a lighter wood. You can see it in the photograph. Looking around the café, such parallel lines were everywhere. Planks of wood lined the walls, vertical, parallel lines stretching up to the ceiling. In the room towards the back of the café, the ceiling also had parallel lines on it which, given I was viewing them from a distance, appeared to converge with the effect of perspective. It is difficult to know whether these effects were deliberate in a gallery/café so dedicated to an exploration of the visual but I like to think that the small twin lens reflex camera on a shelf (which sadly turned out to be a pencil sharpener on sale) was a nod to this idea shifting lines of sight and perspective.

By definition, two parallel lines are lines that will never meet, no matter how far the lines are extended. If they were to meet at any point, they would not be parallel. This offers a way of measuring the distance to stars as well as providing food for thought on our way of seeing our place in the universe. The idea is that of parallax. If you were to measure the relative position of a star against the background of stars at midnight in June, and then go back to measure the same star relative to the same background at midnight six months later in December, you may find that the star seemed to have moved. The amount it moves, its parallax, is determined by how close the star is to the earth (have a look at the diagram).

parallax and coffee

As the point of view moves around the Sun (represented here by a V60), the closest coffee bean appears to shift relative to the background coffee beans.
The lower two diagrams are an attempt to see things from the perspective of the Lego person separated by “6 months” distance.

Take as an example the star Sirius. Located relatively close to us at a mere 8.6 light year distance, Sirius has a parallax of 0.38 arc seconds or, equivalently, about 0.0002 of the angular diameter of the moon viewed from Earth¹. Stars that are further away are going to have an even smaller parallax until the parallax becomes so small as to be difficult to measure. Even for nearby stars such as Sirius, the small size of the effect meant that it wasn’t until 1838 that it was first measured. Which may be part of the reason that the theory of Aristarchus (310-230BCE) never caught on when it was proposed.

Aristarchus was an early proponent of the idea that the Earth went around the Sun (and not the other way around). The Greek’s realised that if Aristarchus was correct, there should be a parallax effect for the stars viewed at different times of the year (every 3 months)¹. Unfortunately, the Greeks also considered that the stars belonged to a thin shell, so effectively all the stars were at the same distance from the Earth. Consequently, the parallax effect that they looked for (if Aristarchus was correct) was for two stars on that shell to move first towards then away from each other as the Earth circled the Sun¹. They never observed this effect and so considered the heliocentric theory “inconsistent with observations”¹. Although we would now say that the fact that they didn’t observe any such shift is consistent with the huge distances to the stars (and therefore small shifts) involved, for the ancient Greeks it was a problem. As Archimedes commented, if Aristarchus’ theory had been true, it would mean that the universe was much bigger than they at that time thought.

Guardini has written about the effect on the human psyche of this changing idea of the universe and our own place in it (from the Greek’s idea of finite and limited, to finite with a God outside, to infinite and back towards finite but incredibly large). Do our ideas, our models, about the universe affect not only how we interpret the experimental evidence we see, but also our way of being, our behaviour towards our fellow humans and our planet?

Viewing things from a different angle, seeing the effect of a change of line of sight, it brings us right back to the photography in the gallery and the twin lens camera on the shelf. There are certainly many things to contemplate while enjoying a coffee at The Observatory. Which means a second espresso should definitely be a possibility.

You can view some street photography, including some photographed with a twin lens Microcord TLR camera on Artemisworks gallery here.

The Observatory is at 64 Marchmont St, WC1N 1AB

¹Astronomy, the evolving universe (6th edition), Michael Zeilik, John Wiley & Sons, 1991

 

Why politicians should drink loose leaf tea

Coffee Corona

Notice the rainbow pattern around the reflected light spot?
The universe is in a cup of coffee but to understand rising sea levels, it’s helpful to look at tea.

The universe is in a glass of wine. So said Richard Feynman. It has been the focus of this website to concentrate instead on the universe in a cup of coffee, partly because it is much easier to contemplate a coffee over breakfast. However there are times when contemplating a cup of tea may be far more illuminating. Such was the case last week: if only a politician had paused for a cup of tea before commenting on rising sea levels.

There are many reasons to drink loose leaf tea rather than tea made with a bag. Some would argue that the taste is significantly improved. Others, that many tea bags contain plastic and so, if you are trying to reduce your reliance on single-use plastic, loose leaf tea is preferable. Until last week though, it had not occurred to me that brewing a cup of tea with a mesh ball tea infuser (or a similar strainer) was a great way to understand the magnitude of our problem with rising sea levels. If a stone were to enter a pond, the pond-level would rise; if a spherical tea strainer (full of loose leaf tea) were to be placed in a cup, the soon-to-be-tea level would rise.

Clearly, because we know our physics, we would not place a strainer of tea into an existing cup of hot water as we know the brewing process relies on diffusion and turbulence, not just diffusion alone. So what we more commonly observe in the cup is actually a tea-level fall as we remove the straining ball. Fortunately, we can calculate the tea level decrease, h:

A schematic of the tea brewing process

My cylindrical tea mug has a radius (d) of 3.5cm. The radius (r) of the mesh ball is 2cm. We’ll assume that the tea leaves completely expand filling the mesh ball so that the ball becomes a non-porous sphere. Clearly this bit is not completely valid and would anyway create a poor cup of tea, but it represents a worst-case scenario and so is good as a first approximation.

Volume of water displaced = volume of mesh ball

πd²h = (4/3)πr³

A bit of re-arrangement means that the height of the tea displaced is given by

h = 4r³/(3d²)

h = 0.87 cm

This answer seems quite high but we have to remember that the mesh ball is not completely filled with tea and so the volume that it occupies is not quite that of the sphere. Moreover, when I check this answer experimentally by making a cup of tea, the value is not unreasonable. Removing the mesh-ball tea strainer does indeed lead to a significant (several mm) reduction in tea level.

Earth from space, South America, coffee

Assuming we are truly interested in discovering more about our common home, we can gain a lot through contemplating our tea.
The Blue Marble, Credit, NASA: Image created by Reto Stockli with the help of Alan Nelson, under the leadership of Fritz Hasler

What does this have to do with politicians? Last week a congressman from Alabama suggested that the observed rising sea levels could be connected with the deposition of silt onto the sea bed from rivers and the erosion of cliffs such as the White Cliffs of Dover. If only he had first contemplated his tea. Using a “back of the envelope” calculation similar to that above, it is possible to check whether this assertion is reasonable. As the surface area of the oceans is known and you can estimate a worst-case value for the volume of the White Cliffs falling into the sea, you can calculate the approximate effect on sea levels (as a clue, in order to have a significant effect, you have to assume that the volume of the White Cliffs is roughly equal to the entire island of Great Britain).

Mr Brooks comments however do have another, slightly more tenuous, connection with coffee. His initial suggestion was that it was the silt from rivers that was responsible for the deposition of material onto the sea bed that was in turn causing the sea level to rise. About 450 years ago, a somewhat similar question was being asked about the water cycle. Could the amount of water in the rivers and springs etc, be accounted for by the amount of rain that fell on the ground? And, a related question, could the amount of rain be explained by the amount of evaporation from the sea?

The initial idea that the answer to both of those questions was “yes” and that together they formed the concept of the “water cycle” was in part due to Bernard Palissy. Palissy is now known for his pottery rather than his science but he is the author of a quote that is very appropriate for this case:

“I have had no other book than the heavens and the earth, which are known to all men, and given to all men to be known and read.”

Reflections on a cup of tea.

Attempts to quantify the problem and see if the idea of the water cycle was ‘reasonable’ were made by Pierre Perrault (1608-80) in Paris and Edmond Halley (1656-1742) in the UK. Perrault conducted a detailed experiment where he measured the rain fall over several years in order to show that the amount of rain could account for the volume of water in the Seine. Halley on the other hand, measured the amount of evaporation from a pan of heated water and used this value to estimate the evaporation rate from the Mediterranean Sea. He then estimated the volume of water flowing into that sea from a comparison to the flow of the water in the Thames at Kingston. Together (but separately) Perrault and Halley established that there was enough water that evaporated to form rain and that this rain then re-supplied the rivers. Both sets of calculations required, in the first place, back of the envelope type calculations, as we did above for the tea-levels, to establish if the hypotheses were reasonable.

If you missed the coffee connection, and it was perhaps quite easy to do so, the question that Halley studied concerned the rate of evaporation as a function of the water’s temperature. This is something that is well known to coffee drinkers. Secondly however, one of Halley’s experiments about the evaporating water was actually performed at a meeting of the Royal Society. It is known that after such meetings, the gathered scientists would frequently adjourn to a coffee house (which may have been the Grecian or, possibly more likely, Garraways). As they enjoyed their coffee would they have discussed Halley’s latest results and contemplated their brew as they did so?

What this shows is that sometimes it is productive to contemplate your coffee or think about your tea. Notice what you observe, see if you can calculate the size of the effect, consider if your ideas about the world are consistent with your observations of it. But in all of it, do pause to slow down and enjoy your tea (or coffee).

Tales from the worm bin

the cup before the worm bin

How it all began.
“Completely compostable”
But how compostable is it?

It is hard to believe but it was one year ago this week that the composting experiment that became #willitcompost started. The idea was to test just how “compostable” a coffee cup described as “completely compostable” really was. The problem is that “compostable” has a legal definition but it is not one that you or I may immediately recognise. Legally for a take-away coffee cup to be described as compostable it has to completely disappear within 6 months in an industrial composting facility. Industrial composting is quite different from home composting. In the former, the temperature is kept at (58±2)ºC while in my composting worm bin, it can get very cold indeed.

As has been written about elsewhere, in the absence of better industrial composting facilities, there is very little virtue involved by swapping a disposable cup for a compostable one, to combat the problem of waste it would be far better to remember your re-usable. However, what if you had a composting bin at home? How long would it take the cup to compost? And even, would it compost?

So every week for the past 52 weeks, I have posted a photo of the cup, composting away, in the worm bin. It seems clear that although it will eventually compost, more than 52 weeks is a long time to wait and not practical if you are drinking multiple take-away coffees.

willitcompost

51 weeks later, the lining and part of the rim of the cup are still in the worm bin. Clearly the worms have better things to eat.

In the meanwhile, other questions have been raised. What about other coffee packaging such as the bags for roasted coffee beans? What about the compostable “glasses”? Can anything be done to speed up the composting of the cup?

Last month, the opportunity came to start a new experiment testing these questions. A compostable coffee roasting bag from Amoret Coffee (which was reviewed on Bean Thinking here) was placed in the second shelf of the worm bin together with a cup, a compostable “glass” and a section of food packaging. The cup and the ‘glass’ were cut in half before being placed in the worm bin. One half of each was left as it was but the other half was soaked in (initially boiling) water for 12 hours. The idea of this was that part of the problem that has slowed the composting of the original cup was the lining that is designed to hold hot liquids without leaking. If we could somehow weaken that lining before placing it in the worm bin, perhaps the composting process would be accelerated?

talesfromthewormbin

A roasted coffee bag, a cup (split in two, see main text), a compostable glass and some food packaging, but will they compost?

Starting in late March provides the best chance of a quick composting process due to a particular aspect of worm behaviour. Although the composting worms will continue to eat the waste put into the composting bin throughout the winter, they do slow down quite a lot. If you have a worm bin, you may notice that the amount of waste that you can put into the bin decreases during the winter months. On the other hand, as the weather improves, the worms seem to eat everything very quickly so, to provide the best conditions for composting, the weather has to be reliably warm (or at least, not freezing).

Rather than once a week, updates will be approximately once per month both on social media and in the Bean Thinking newsletter. So keep your eyes on #talesfromthewormbin on twitter or subscribe to the newsletter. Do we really take our environmental responsibility seriously by using compostable packaging or, ultimately, is a more radical approach to waste, single use packaging and consumerism necessary?