Nitro-brew? Not this week. Coffee and liquid nitrogen at Chin Chin Labs (a nitrogen dewar is on the table behind the coffee grinder).
It is true that Chin Chin Labs is not really a coffee-based café (although it does serve decently prepared, Monmouth roasted, coffee). Nonetheless, there is no question but that it has to be included as a cafe-physics review on Bean Thinking. Why? The answer is in the photo of the coffee grinder, though you may have to look carefully. You see, Chin Chin Labs is offering a different sort of café experience. Not coffee nor tea, but ice cream, indeed, Chin Chin Labs in Camden Lock advertises itself as the ‘future of ice-cream’ and the reason it does so is because here, all the ice cream is made with liquid nitrogen.
There are only 3-4 tables inside Chin Chin Labs which makes it more of a take-away bar than a sit down café. As you enter, a large dewar of liquid nitrogen is on your left, just behind the counter. Arranged behind this large dewar are a set of smaller dewars while on one of the ice cream preparation tables another (small) dewar sits with a pipe in it, ready for the nitrogen to be decanted out. If all these dewars are full, that is a lot of liquid nitrogen. The coffee is decent and prepared in the normal styles (espresso, Americano, cappuccino, latte), though this place is really not about the coffee (one of the staff expressed surprise that I’d ordered a coffee and not an ice cream). Next to the espresso machine were a set of glass beakers and glass containers as you would expect to find in a chemistry set, while the aprons worn by the staff had “Chin Chin Labs” written in a glittery, (futuristic or disco?), font.
Nitrogen, nitrogen everywhere…
There are many fun things that can be done with liquid nitrogen. From creating ice cream, through to shattering flowers and even to a possible solution for the energy storage problem (info here). Not to mention its important use as a coolant in all sorts of physics experiments and for biological storage. I have spent many hours decanting liquid nitrogen into buckets for basic experiments or into the first cooling stage of very strong magnets (such as are used in MRI machines).
However, at -196ºC, liquid nitrogen is not a liquid that can be treated flippantly. Although it can be fun, and handled correctly there is no problem, it can nonetheless be very dangerous. Which is why something else about Chin Chin Labs struck me quite hard. While there were glass beakers and containers that a cartoon may feature as part of a science ‘lab’, there was none of the equipment that you would actually expect to see in a real lab where liquid nitrogen is used. In our lab, oxygen monitors beep (annoyingly) every 60 seconds*, eye goggles and proper cryogenic-suitable gloves are stored in a highly visible position easily accessible to anyone in the lab. Risk assessments are prominently displayed so that everybody is aware of the risk of oxygen depletion (leading to suffocation) were the nitrogen dewars in the lab to fail and suddenly vent all that liquid nitrogen into nitrogen gas in the lab. These things are not fun, but are a necessary part of running a lab in which cryogenic liquids (including liquid nitrogen) are stored and used.
The final result: vanilla nitrogen-ice-cream.
It is this contrast, between what is expected of a lab (glass beakers and complicated looking valves on the dewars) and what is in a lab (safety equipment and complicated looking valves on the dewars) that struck me. What do people, the public, café owners, think a lab looks like? What do they (you?) think a scientist looks like? Do we prefer indulging in our stereotyped ideas of a lab rather than think about the reality of life in a real science lab?
I am sure (or at least I hope) that the safety equipment, oxygen monitors etc. are present, but hidden under the counter, at Chin Chin Labs. It should always be possible to have fun with liquid nitrogen, whether in a lab or a café. And the ice cream is definitely worth trying (according to the person I visited Chin Chin Labs with). But, if you happen to pass by Camden Lock and try some nitrogen ice-cream, please do spend a minute to ask yourself, what you think a scientist, or a lab looks like. And do let me know what you think, I’d be interested to know.
Chin Chin Labs is at 49-50 Camden Lock Place, NW1 8AF
* In the event of the failure of a liquid nitrogen dewar, the oxygen in the room would be displaced. The resulting decrease in oxygen concentration can cause sleepiness, mental confusion or in the case of severe oxygen depletion, coma and death (more info here, opens as pdf). Oxygen monitors check the oxygen level in the room is at a safe level. The beep is annoying but tells us that the monitor still has battery and is checking the oxygen level in the room.
Three billion miles away, on an object formerly known as the planet Pluto (now sadly demoted to the dwarf planet Pluto), there exists a plain of polygonal cells 10-40 km across, extending over a region of about 1200 km diameter. Last year, the New Horizons mission photographed this region and these strange shapes (see photo) as the probe flew past Pluto and its moon Charon. But what could have caused them, and perhaps more importantly for this website, can we see the same thing closer to home and specifically in a cup of coffee? Well, the answer to those questions are yes and probably, so what on Earth is happening on Pluto?
Pluto moves in an highly elliptical orbit with an average distance to the Sun of 5.9 billion km (3.7 billion miles). Each Pluto year is 248 Earth years but one day on Pluto is only 6½ Earth days. As it is so far from the Sun, it is very cold on Pluto’s surface, somewhere between -238 to -218 ºC. The polygons that were photographed by New Horizons are in the ‘Sputnik Planum’ basin where the temperatures are at the lower end of that scale, somewhere around -238 ºC. At this temperature, nitrogen gas (which makes up 78% of the Earth’s own atmosphere) has not just liquified, it has solidified; turned into nitrogen ice. These polygons are made of solid nitrogen.
But solid nitrogen is a very odd type of solid and in fact, at the temperatures on Pluto’s surface, solid nitrogen is expected to flow with a very high viscosity (like an extremely gloopy liquid). And it is this fact that is the clue to the origin of the odd polygons (and the link to fluids like coffee). Pluto is not just a cold dead rock circling the Sun, but instead it has a warm interior, heated by the radioactive decay of elements in the rocks making up Pluto. This means that the base of the nitrogen ice in the Sputnik Planum basin is being heated and, as two groups writing earlier this summer in Natureshowed, this leads to the nitrogen ice in the basin forming convection currents. The warmer nitrogen ‘ice’ at the bottom of the basin flows towards the surface forming convection patterns. It is these nitrogen convection cells that appear as the polygons on the surface of Pluto.
Of course, convection occurs in coffee too, we can see it when we add milk to the coffee and watch the patterns form or by observing the dancing caustics in a cup of tea. So why is it that we see stable polygons of nitrogen on the surface of Pluto but not coffee polygons on the surface of our coffee? The first point to note is the time-scale. Although the polygons on Pluto are moving, they are doing so much more slowly than the liquid movement in a cup of tea or coffee, at a rate of only a few cm per year. But secondly, the type of convection may be different. Although both of the papers in Nature attributed the polygons on Pluto to convection, they differed in the type of convection that they considered was happening. McKinnon et al., suggest that the viscosity of the nitrogen on Pluto is much greater on the surface of the basin than in the warmer interior and so the surface flows far more slowly. This leads to cells that are much wider than they are deep. We would not expect such a drastic change in the viscosity of the coffee between the (cool) top and (warm) bottom of the cup! In contrast, Trowbridge et al., think that the cells are Rayleigh-Bénard convection cells, circular convection cells that form such that the cells are as wide as they are deep. This sort of convection is seen in a coffee cup as well as in the sky on cloudy days: On the Earth, clouds often form at the top (or bottom) of Rayleigh-Benard cells, where hot humid air meets cold dry air (more info here). But to form cells that you can see in your coffee (such as are on the surface of Pluto) you would need the coffee to be in a fairly thin layer and heated from below. You would also need some way of visualising the cells, either with an infra-red camera or with powder suspended in the liquid, it would be hard I think to see it in coffee alone. However, you can see these cells in cooking oil as this video shows:
As well as providing the link to the coffee, the different types of convection on the surface of Pluto hypothesised by Trowbridge and McKinnon have consequences for our understanding of the geology of Pluto. If the cells are formed through Rayleigh-Bénard convection (Trowbridge), the basin has to be as deep as the cells are wide (meaning the basin has to be 10-40km deep with nitrogen ice). If McKinnon is correct on the other hand, the basin only needs to be 3-6 km deep. It is easy to imagine that an impact crater could cause a shallow crater such as that needed for McKinnon’s mechanism. A deeper crater would create another puzzle.
If you do manage to heat coffee (or tea) from below and form some lovely Rayleigh-Bénard cells while doing so I’d love to see the photos or video. Please do contact me either by email, Facebook or Twitter. Otherwise, if you just enjoy watching the patterns form on your coffee, it’s worth remembering that there could be an entire cosmos in that cup.
Jaz and Jul’s, The Chocolate House on Chapel Market
The London coffee houses of the seventeenth and eighteenth centuries have entered history as Penny Universities, places of debate and centres of news. Together with the (scientifically based) Grecian, there was Jonathan’s in Exchange Alley (origin of the stock exchange) and Lloyd’s on Tower Street (associated with insurance). But along side these coffee houses there were the chocolate houses, Whites and Ozinda’s on St James’ St and the Cocoa Tree in Pall Mall. White’s in particular developed such a reputation that it features in Hogarth’s The Rake’s Progress (which can be seen at Sir John Soane’s museum).
So it is an interesting bit of history repeating to find Jaz & Jul’s, a chocolate house on Chapel Market. The interior here is very far from Hogarth’s rendering of White’s. Here, light fittings hang from the ceiling like drops of chocolate about to melt into the café while photographs of cocoa plants and farms adorn the walls. Moreover the emphasis on social responsibility, including in sourcing, mean that this establishment is worlds away from the debauched shenanigans at White’s. Their coffee is roasted and supplied by Monmouth while the cakes are hand made and, needless to say, very chocolatey. The light and fluffy chocolate-Pimms cake arrived with my coffee presented on a plate and matching cup that reminded me of a mint-chocolate-chip ice cream.
The chocolate counter at Jaz and Jul’s
The side of the counter was tiled to resemble a bar of chocolate, which immediately reminded me of the physics and chemistry of chocolate crystallisation. However, the physics connection of this cafe-physics review is a bit more lateral than that. Soon after I had enjoyed my incredibly chocolatey cake at Jaz & Jul’s, a study was released which showed that Britons were significantly under-reporting their daily calorie intake. Could it be that the obesity epidemic is a result of us eating too much rather than merely exercising too little? Apparently, rather than consume the (recommended) levels of 2500 kcal for men and 2000 kcal for women, many people were eating up to 3000 calories per day. Everything in moderation of course and there was plenty of room in my own calorie count for that great piece of cake (honestly). But the word ‘calorie’ turns out to have a connection with chocolate in a more unexpected way.
Calorie comes from the Latin, calor, meaning heat which in turn hints at how we used to think about heat itself. While we now think of heat as energy, which is why it doesn’t even strike us to equate the ‘energy’ in the chocolate cake with the number of kilo-calories in it, this is not how heat was always viewed. In fact, in the eighteenth century, about the time of the old chocolate houses, heat was thought of as a type of fluid, caloric. Caloric was thought to be able to flow in and out of all substances. When something got hot it was because the caloric flowed into it, when something got cold, it was because the caloric had leaked out. Caloric theory was in many ways very successful in understanding heat and heat processes. For example, the theory easily explained thermal expansion, if a fluid had to flow into something in order for that thing to warm up, then surely, the fluid has to occupy some space, the object must expand to hold it!
Coffee with the Chocolate-Pimms cake.
One area that was tricky for caloric theory though was the fact that friction could cause something to heat up. Such heat generation is crucial for our extraction of chocolate. Once harvested from the plant and cleaned, the cocoa bean is first roasted then shelled to leave the cocoa ‘nibs’. These nibs are then ground more finely. As they are being ground, the friction caused by grinding is enough to cause sufficient heat to melt the cocoa butter in the nibs which is then extracted and retained for later use*. How could you explain this heating if you thought of heat as a fluid? The traditional explanation was that as the two objects rubbed against each other (in this case, nib and stone grinder), the caloric fluid would be squeezed out, it would appear as if heat had been generated.
Benjamin Thompson, Count Rumford (1753-1814), disagreed with this explanation of heat. In the course of a colourful career he had been involved in manufacturing cannons in Bavaria. Rumford had noticed that a lot of heat was generated each time a cannon shaft was bored out. The heat produced continued as long as the grinding continued. If the heat were due to the cannon leaking caloric, surely there would be a point at which the cannon stopped getting any hotter. Yet this did not happen. Rumford suggested (correctly) that instead what was happening was that the energy generated by the boring was being transferred into the metal of the cannon, causing microscopic motion.
Although the heat as motion/energy idea eventually caught on, caloric in some ways still survives in the name that we give to our food energy intake. And so we can return to the cake, could it be that spending time thinking about the caloric in the cake can justify the calories consumed eating it? Sadly the jury is out on whether thinking counts as calorie counting exercise. It seems that the brain’s energy consumption is already so great (at 20% of our resting metabolic rate), that intense thinking does not add too much to the energy consumed by the brain. So we’ll need another excuse and I don’t think we have to look far. The coffee and chocolate at Jaz & Jul’s is delicious enough to justify a significant chunk of your daily calorie count, just based on considerations of taste. Everything in moderation!
Jaz and Jul’s is at 1 Chapel Market, N1 9EZ
*”Chocolate: A Global History”, by Sarah Moss and Alexander Badenoch, published by Reaktion Books, 2009
I had been waiting for an opportunity to try the Coffee Jar for a fair while. It is not that it is in a remote location, it is in fact situated on Parkway just five minutes walk from Camden or Primrose Hill. Nonetheless it feels as if it needed a special trip to get there (and, though this is pre-empting the end of this cafe-physics review, it does deserve such a ‘special trip’). Inside, there is seating at the window and running along one wall, and although it is not the smallest of cafés, it is certainly a ‘cosy’ one. This is not intended as an estate agent’s euphemism but instead to emphasise the additional meanings of this word to convey a warmth and friendliness about the space that the Coffee Jar definitely has. So far, we have been twice (see, the ‘special trip’ is worth it!). The coffee comes from Monmouth and so unsurprisingly, on the two occasions I had a coffee there (Americano and Soya Latte), it was very well done and enjoyable. At the front of the counter are a wide selection of home made cakes and cookies. While this presentation can be awkward for allergy sufferers (nutty cakes or cakes with loose nuts on top are placed side by side with the nut free options which could give contamination issues), the cookies were very good (more on the cookies later).
As befits the name, hand painted jars and coffee mugs decorate the end of the tables (and can be purchased should you wish). Individual art pieces decorate the walls while the window is painted with a scene that is somehow mirrored (shadowed?) in the ink prints on the take-away cups. All in all, there is plenty to notice in this “cosy” space. And so it took a fairly long time before I noticed the fish that was dangling above my head.
Apologies for the blurry photo but you can see the robot fisherman on the shelf.
Yes, this seemed an odd thing to me too, so I checked and indeed, a wooden fish was suspended on a string from something hidden on the shelf above my seat. At this point, an opportunity arose to go and sit at the window and so I was able to turn and look properly at the cause of the suspended wooden fish which was actually a toy robot. It just gets more surreal. But indeed, on the shelf above the seats against the wall was a toy robot fishing, a wooden fish hanging at the end of his (her?) line.
A robot that is fishing can prompt a large number of questions which seem to me to be at the intersection of science and philosophy. To what extent has automation improved our lives? Is it a good or a bad thing to use robots in jobs traditionally done by humans? Moving away from robots and towards computers, what about artificial intelligence? Much has been written about artificial intelligence in recent years. There is some angst about whether robots will come to take-over the world with an ability to think that far surpasses our human ability. Alternatively, there are people who look to artificial intelligence with the hope that it will help us drive cars or investigate pollution or all manner of other (to a greater or lesser degree) useful things. One test that has been suggested as a way of establishing whether any particular computer, or artificial intelligence, can think is the Turing test proposed in 1950 by Alan Turing. A prize set up to reward the first computer “chatbot” that could reliably mislead human judges into thinking that it was itself a human (the Loebner prize) has so far not been won (a prize is awarded each year for the most convincing chatbot but so far, none has been so reliably convincing as a human to win the top, “gold” prize).
Unusually I had a soya latte.
But the robot on the shelf was not represented as thinking but as fishing, an occupation that is associated with relaxation. This robot was not just thinking, it was taking time out to relax; it was represented as being alive and sentient. This prompts a rather different question to that of merely intelligence: At what point do we say that something is living? How can we define life? As could perhaps be expected, NASA has taken some time to consider this question. As they say on their website:
“Comparing the semantic task [of defining life] to the ancient Hindu story of identifying an elephant by having each of six blind men touch only the tail, the trunk, or the leg, what answer a biologist might give can differ dramatically from the answer given by a theoretical physicist.”
Which may make you wonder well, what would a theoretical physicist say about how we could define life? Erwin Schrödinger (1887-1961) had a very interesting, physics-based, definition of life. Although he is now perhaps more famous for his equation or his cat, in 1944 he wrote a book called “What is Life” (opens as pdf). To very briefly summarise, the argument goes that the tendency of all inanimate objects is towards equilibrium. A hot cup of coffee will lose heat to its immediate environment and so reach the same temperature as its surroundings, a small amount of blue food colouring at the bottom of a glass of water will eventually colour the entire glass a paler blue. To be alive is to defer this state of equilibrium for to achieve equilibrium is the same thing as death. Schrödinger argued that rather than merely consume energy, living things consumed negative entropy from their food-stuff. Entropy is a quantity introduced with the theory of thermodynamics. It is often taken as a measure of the order in a system (though there are caveats to that). The second law of thermodynamics states that for a closed system, the entropy of the system will either increase or stay the same. This suggests that to avoid equilibrium, or equivalently to avoid death, the living thing must consume order (or negative entropy) and somehow stave off this tendency to maximum entropy. To answer the objection that it would be easy to consume negative entropy by eating diamonds (which are highly ordered crystals) and so therefore that there has to be more to life than this, Schrödinger expanded on the thermodynamics of his argument. That bit gets quite technical and so is another reason that, if you are interested, it is worth getting hold of the book.
So to return to one of the first questions but phrase it in a slightly different way. Could a robot cookie maker replace the “home-made” cookies that were on offer in the Coffee Jar? It turns out that this is a subject that my often-times cafe-physics review companion (let’s call them J) has quite an opinion about. We visited the Coffee Jar twice partly because of the cookies! It seems to me that J would not have been impressed by the cookies were they robotically mass manufactured. There was something very appealing in the home made quality of them. So, there we go, one of the questions answered neither scientifically nor philosophically but on the very reasonable basis that home made cookies taste and look better. Do let me know if you agree if and when you visit the Coffee Jar.
The Coffee Jar is at 83 Parkway, NW1 7PP
“What is life?” Erwin Schrödinger, Cambridge University Press, first published 1944, my edition published 2013
I had been waiting for an opportunity to try Kin Cafe in Fitzrovia for a while. Having followed them on Twitter, I had been tempted by the large selection of great-looking vegetarian and vegan food choices tweeted almost daily. Although I’m no longer a vegetarian, appetising meat-free meals are always appealing. So it had been on my “to try” list for a long time (preferably for lunch). However, sometimes things don’t work out quite the way you had initially hoped and so it was late afternoon by the time we ended up at Kin, sadly no lunch then. So we settled on an Americano, soya hot chocolate and a slice of Butternut and ginger cake. The coffee (from Clifton Coffee) was very fruity and full of character, highly enjoyable while sitting in the window overlooking the street outside. The cake meanwhile deserves a special mention. Not only was the cake very good, the helpful staff at Kin were very confident in their knowledge that this cake was nut-free and they also ensured that the new member of staff (being trained) used a new cake slice to serve it. Extra ‘points’ for a nut-allergy aware café and definitely a tick in the “cafes with good nut knowledge box”.
As we sat with our drinks, one of Beethoven’s quartets was playing through the loudspeakers. For me, Beethoven being played in the background is a bonus for any café but it did, perhaps, mean that I was less sociable than normal with my frequent companion in these reviews; the quartets are too absorbing. I do hope the hot chocolate made up for it.
Tables are supported by struts forming triangles. But this is not the Pythagorean link.
Inside the café, tables along the wall were each stabilised by a diagonal support. A practical arrangement that had the visual effect of forming a triangle with the wall. While this did make me think about force-balancing and Pythagoras, this is not the link to Pythagoras alluded to in the title. No, instead the connection goes back to the Beethoven and the links between music and mathematics. Perhaps we no longer immediately think of music and mathematics as being particularly connected, after all one is an ‘art’ and the other a ‘science’. But music and mathematics have, traditionally, been so inextricably linked that, as Susan Wollenberg wrote in ‘Music and Mathematics’* “… it is their separation that elicits surprise”.
Some of the links between music and mathematics are explored in this TED-Ed talk about the maths to be found in Beethoven’s Moonlight Sonata. This part of the link between music and mathematics comes in the relation between what is known as consonant and dissonant notes. The first part of the Moonlight Sonata is made up of triplets of notes that sound good to our ears when they are played together. As Pythagoras is said to have discovered (see link here, opens as pdf), there is an interestingly simple relation between notes that are consonant with each other. Whether you look at the frequency of the notes or the length of a string required to play them, the ratio of two consonant notes seems to be a simple number ratio.
For example, the A of an oboe has a frequency of 440 Hz*. The A one octave higher is at 880 Hz, a factor of 2. If we took instead a series of notes of frequency f, then we could find a series of consonant notes at f:2f:3f. But now, remembering that octaves are separated by a factor of 2 and that they ‘sound good’ together, this will mean that the ratio of frequencies f:1.5f:2f will also sound good. This set of frequencies just happens to coincide with the C-G-C’ chord that forms the basis of many guitar based pieces of music. As you continue looking at these simple number ratios you can start to build a set of notes that eventually forms a scale.
The artist Fuseli once lived diagonally opposite Kin Cafe. J. James notes that Fuseli was part of the artistic revolution that was paralleled by Beethoven and the Romantics in the musical sphere**.
But the links go deeper than this. In the same book “Music and Mathematics”, JV Field wrote “..in Ancient, medieval and Renaissance times, to claim that the order of the universe was ‘musical’ was to claim that it was expressible in terms of mathematics.” Indeed, Kepler looked for these musical harmonies in the maths of the planetary system. Although he found no ‘harmonies’ in the ratio of the periods of the planets then known, he did find musical scales in the ratios of the speeds of the planets (measured when they were closest to the Sun, at the perihelion, and furthest from the Sun, at the aphelion). Other simple number ratios can be found when we look to different regions of the Solar System. The periods of three of the Galilean moons of Jupiter for example have the ratio 1:2:4 (Io:Europa:Ganymede). While we would no longer describe these patterns as reflecting the harmony of the Universe (see here instead for current understanding), perhaps we ought to ponder the next sentence that Field wrote in the chapter on Musical Cosmology:
“We still believe [that the universe is expressible in terms of mathematics] now. Indeed, mathematical cosmology has proved so powerful that it is perhaps difficult to take a sufficiently cold hard look at the metaphysical basis on which it rests. On the other hand, the explicitly musical cosmologies derived more directly from the Ancient tradition seem sufficiently fantastic to invite instant questioning of their underlying metaphysics…”
One to consider next time you happen to wander into Kin Cafe, or another café playing such mathematical composers as Beethoven.
Kin Cafe can be found at 22 Foley St, W1W 6DT
*Music and Mathematics, Edited by J. Fauvel, R. Flood, R. Wilson, Oxford University Press (2003)
** The Music of the Spheres, J. James, Copernicus (Springer-Verlag), (1993)
Lastly, a video of Wilhelm Kempff playing Beethoven’s Moonlight Sonata. I would really recommend playing it twice, the first time to listen only, the second to watch while Kempff plays. His performance is fascinating.
There’s plenty of plastic in coffee & it’s not just in the obvious take-away cups.
So we’ve probably all done it, walked into a coffee shop and purchased a take-away coffee while in a rush to get elsewhere. It’s the moment that our desired commitment to environmentally responsible behaviour clashes with our (briefly stronger) desire for sustenance on the move. Using a keep-cup (or similar) would avoid this bit of single-use plastic but even so, is this the only plastic that you encounter when you enjoy a coffee? Actually, once you start to notice it, you will find single-use plastic in a number of surprising places.
An initiative called “Plastic Free July” aims to raise awareness of the pervasiveness of single-use plastic as well as to challenge us to do something about it. So, partly as an educational exercise, I signed up to the Plastic Free July, not because plastic is always bad, (there are arguably some very good, even environmental, reasons to use plastic, see below) but because plastic is a substance that takes a long time to break down once discarded and we use it so often even without thinking. So, before revealing just how easy – or hard – it has been to eliminate single use plastic from everyday life for the past couple of weeks, it’s worth taking a look at the problems, benefits and occurrence of plastic in our lives. Particularly while we are enjoying a tea or coffee.
Some definitions
Plastic comes in many forms and Plastic Free July does not aim to avoid all of them. It is single use plastic that is the concern: Bits of plastic wrapping, plastic bags, aroma valves. Things that are used once and then discarded. Can you avoid using these, even for one week or even just one day? Why not sign up and commit yourself to trying to find out.
Plastic Problems
One planet. One home. The Blue Marble, Credit, NASA: Image created by Reto Stockli with the help of Alan Nelson, under the leadership of Fritz Hasler
Two of the major issues with our use of plastics are the problems of littering and that of degradability, particularly when that litter finds its way into the oceans. Between 60-80% of marine litter is plastic. It can cause the deaths of marine life not just through its being eaten (thereby causing internal injury or malnutrition), but also by entangling sea creatures and so causing death through drowning or other injury. Moreover, the bits of plastic that float around our oceans can provide a home to various micro-organisms transporting them around the world to areas of the planet that they would not ordinarily have been able to reach.
Nor is it just a problem for the oceans. Plastic takes many centuries to decompose and although there are plastics that decompose more quickly (oxo-biodegradable and compostable, more details below), clearly there is a need to reduce the amount of plastic we throw away. A further problem with plastics is that their manufacture requires the use of a limited resource. 4-5% of global petroleum production is used for the manufacture of plastic∗. But nor is it just petroleum products, the thing that makes carrier bags opaque is an additive called TiO2. It is therefore somewhat sobering to realise that 25% of the plastics manufactured in the US are used in packaging* and 37% of the plastics produced are for disposable items. Clearly we have room to live less wastefully here.
Why it’s not all bad
Is it better to swap to paper packaging? It may depend on what problem you’re trying to solve.
Although there is a big problem with plastic waste, a different environmental problem has arguably benefited from our use of plastic packaging: The greenhouse effect. Consider the way that ground coffee is often sold in a supermarket. Frequently the coffee comes in metallised plastic packaging complete with plastic air-valve (or aroma valve). Alternatively, coffee can be packaged in a steel can (as used by a well known coffee roasting blend). Steel is 100% recyclable and so is good for the degradability/litter problem. However it is heavy and cylindrical. This means that to transport an equivalent amount of coffee in steel cans costs more, both in terms of economic and environmental costs, than the lighter, less bulky plastic of the alternative*.
What about paper packaging? It is interesting that even here, the situation is not clear-cut. A study concerning the greenhouse gas emissions involved with the manufacture and transportation of different sorts of shopping bag had what may be a surprising conclusion. In order to achieve a lower CO2 footprint than a standard plastic shopping bag re-used once as a bin-liner, a paper shopping bag would have to be re-used 4x while a cloth bag would have to be re-used a staggering 173x. You may well argue (as I have) that it is still better, environmentally, to buy your coffee in paper packaging, but if thinking purely in terms of the CO2 emissions, you may want to try to find a way to re-use the coffee bag a few times.
Lastly, the litter and degradation problem need not be insurmountable. In recent years, various manufacturers have sought to make plastic degrade more rapidly than ordinary plastic. Oxo-biodegradable plastic has additives in it that, when exposed to UV light, eg. from the Sun, help the (otherwise perfectly ordinary) plastic to completely biodegrade. The process takes a controllable amount of time that can even be as little as 2 years. Compostable plastic too is being developed but there should be caveats on the name. “Compostable” is defined as “industrially compostable” (meaning it degrades if held at a steady 58C), it does not necessarily mean that it composts in your compost heap.
There’s plastic in my coffee?
Aroma valves: are they worth the environmental cost?
So, we’re aware of the problem and want to do something about it but how much is single use plastic really a problem for coffee (or tea) drinkers? Take-away cups are the obvious source of single-use plastic, but plastic can be found in many places as we enjoy our brew. If we are having coffee in a café (even if it is not take out), how about the spoon for the sugar, plates for the cakes or even wrapping around the chocolate bars? If you drink your coffee with milk (cow, soy or almond) it will often come in plastic bottles, yes these could be recycled but would it be better if they were made from something else? (It is an interesting fact that more plastic was sent for recycling in the UK than was used by consumers†).
An easy way of reducing your plastic use would be to use your own mug as a take-away cup (keep-cups for example are designed to be of the correct size for the cafe industry). And there may even be other advantages to you in bringing along your own cup: For Danny S Parker, taking along his own cup for his coffee allows him to better enjoy the coffee, as he says “If you choose a wide mouth cup… the involvement of the nose in the taste on the tongue will accentuate flavour and enjoyment.” Reducing your plastic consumption could mean that even a take-away coffee can provide a moment to enjoy your brew.
What about if you only ever drank coffee at home? Where’s the plastic there? Well, how do you buy your coffee? Do you buy from a coffee roaster that insists on using bags with ‘aroma valves’? These valves cannot be recycled currently and so inevitably contribute to plastic waste. Is this packaging really necessary for the way that you buy your coffee? (See here for an interesting taste comparison of coffee stored in bags with/without aroma valves). Meanwhile, the coffee itself is frequently supplied in a metallised plastic packaging, does the roaster you buy from try to minimise the environmental cost by using recycled/oxo-bio/compostable/paper packaging? Why not ask them?
And tea drinkers, you do not get away with it! There’s plastic involved in tea drinking too. Tea bags are often supplied in cardboard packaging that is then wrapped in plastic, and even loose leaf tea can come in paper bags with plastic windows or metallised plastic bags. Worryingly, even tea bags themselves can occasionally be made of a plastic material that does not break down in a composting bin‡. Plastic truly gets everywhere.
An honest appraisal of how my plastic free July has gone so far
Giving up plastic can mean taking the opportunity to enjoy your coffee properly.
So, nearly halfway through July and my attempts at being “plastic-free” are mixed. Some things are relatively easy to change, a metal tea strainer and loose leaf tea replaced the tea bags when they ran out. The coffee I use at home comes in paper packaging from Roasting House. Other things such as bottles of shampoo could be replaced by shampoo bars (like a bar of soap only for shampoo). Even the soy milk I use at home was easily exchanged for a home-made oat-milk.
However, some things have been difficult. Shopping particularly is not very plastic-free friendly. Although there is advice on taking containers with you in order to buy meat, fish or cheese from the counter in a plastic-free way, I am not sure that this would work in my local supermarket and anyway, they have to weigh the meat/fish/cheese which will involve them putting it on a plastic bag on the scales. Just because I do not walk away with plastic in my hand does not mean that I am not responsible for its use. Cooking oil too frequently comes in plastic bottles and, given the increased weight and therefore transportation costs involved in glass packaging, perhaps this is an example of a good use of plastic. An attempt to move away from aluminium-lined, plastic tube toothpaste to plastic-free tooth tabs has been complicated by the fact that the tooth-tabs are supplied in a plastic bottle. And I’m afraid that I am partial to a bottle of beer occasionally even though they do have plastic lined metal caps.
So, my plastic-free July has been a bit mixed but certainly not single use plastic free (so far). But, it has been worth it in order to really see just how ubiquitous single-use plastic is in our day to day living. Is it possible for you to cut down just a little bit on the plastic that you use every day? Why not sign up to Plastic Free July and see where your challenges lie.
If you are already signed up to Plastic Free July or if you are trying to live in a plastic-reducing way generally I’d love to hear how it’s going. Also if you have an opinion on the use of plastic in the coffee industry (either in cafes or by roasters) do let me know.
*Plastics and the Environment, AL Andrady (Ed), Wiley-Interscience, 2003
† The study was done in 2006.
‡ I was alerted to this initially by a friend’s comment that certain pyramid-type tea bags never seemed to break down on their compost heap.
Weather for Wimbledon? It was raining when we tried Brickwood in Clapham
It was raining heavily as we met friends for coffee at Brickwood, near Clapham Common, a few weeks back. Inside it was fairly crowded so we were shown to a cosy little area downstairs where we found a table. The staff were all friendly and with coffee roasted by Caravan, it was easy to sit and enjoy a great Americano while waiting for the others to arrive. Sadly, all of the cakes on the menu contained nuts (with the exception of scones). This was a shame because it was otherwise an interesting place to sit and observe the surroundings and it would have been nice to have been able to give it a ‘tick’ in the cafes with good nut knowledge box*. Still, the coffee was very good and there was plenty to observe, even in the basement.
Glancing around the room, the first thing that struck me was a white board on the wall. Taken together with the artificial lighting (necessitated by the area being in the basement), this was highly reminiscent of the maths ‘common room’ at work. A further mathematical connection comes from the fact that the grandfather of John Venn (of the Venn diagram) lived nearby. A prominent local clergyman, Venn St, just around the corner from Brickwood, is named after him. Still, that is quite a digression. There were also interesting bits of physics and science to notice in the café itself.
Grass or concrete? What factors control the bounce of a tennis ball.
Downstairs, the floor was covered in what appeared to be an artificial grass. This gave the whole experience of having a coffee here a bit of a surreal twist. Just as happens with real grass, a path was visible on the ‘grass’ where people had walked, something that can be used when rambling in the country to help you find your way around (when GPS or map temporarily fail you). The book “The Walker’s Guide to Outdoor Clues and Signs”gives many such details about how to navigate in the country without a map (including how to tell from trees which way is North).
However, as we are now in the second week of the Wimbledon Tennis tournament, this cafe-physics review is going to have a tennis slant instead. We could think about how different it would be were we to drop a tennis ball onto the ‘grass’ downstairs, or (what I remember to be) the wooden floor upstairs. Tennis started off as an indoor sport, played on courtyards in stately homes and monasteries. ‘Lawn tennis’, or what we now recognise as just ‘tennis’, developed in the nineteenth century and was played on grass. Thinking about how a tennis ball would bounce on the floor in the basement or upstairs in Brickwood is therefore somehow reminiscent of the history of the sport.
Like being in the maths common room but with better coffee and flowers
Tennis balls are designed to bounce 53-58 ” (134.6-147.3 cm) when dropped onto a concrete floor from a height of 100″ (254 cm). Other surfaces have different elasticity and/or friction. The behaviour of the ball will be quite different therefore when it bounces on different surfaces, affecting the speed (and therefore height) and even angle of the bounce (for more info on the physics click here). The different characteristics of the surfaces mean that different types of play are required to succeed on the court. To be successful across all courts (from the clay of Roland Garros to the Decoturf of the US Open and the grass of Wimbledon) requires a tennis player who can adopt many different playing styles. Would it help a tennis player to have a training in physics and an understanding of the details of aerodynamics, spin and friction that are involved as the ball whizzes through the air? Probably not. But for us mere observers who prefer eating the strawberries and cream and savouring great coffees while discussing the game, a bit of physics may perhaps add to our enjoyment.
Brickwood (Clapham) is at 16 Clapham Common South Side, SW4 7AB
*to be fair, Brickwood did have “good nut knowledge”, they knew all their cakes contained nuts. Perhaps the tag needs revising to be “nut-allergy-friendly”.
Are you a hedonist or a utilitarian when it comes to drinking coffee?
Which part of the process of making and drinking coffee do you enjoy most? How do you rate the importance of smell, taste, touch (even hearing and sight) to the enjoyment of the process of brewing your cup?
It appears that your answer to this question may well be affected by your motivation for drinking your coffee in the first place. Last year, a group of researchers from Switzerland published a study that investigated whether the reason that you drank coffee (i.e. either for sensory enjoyment or just for the caffeine kick) influenced your enjoyment of the experience of making and drinking the coffee.
The researchers looked at how the participants in the study rated their own levels of enjoyment and satisfaction as they progressed through four stages of making coffee.
Water heating
Jar handling*
Cup preparation
Cup drinking
The 60 participants were divided into two groups of 30, those who drank coffee for enjoyment (the hedonists), and those who drank for stimulation (the utilitarians). After checking that both groups of participants rated their levels of pleasure and satisfaction similarly before the experiment started (they did), the participants were repeatedly interrupted while they made their coffee and asked to rate their levels of enjoyment and the importance that they attached to different sensory experiences (smell, sight, touch etc).
A very enjoyable coffee, but which part of the process of making and drinking coffee do you enjoy most?
After stage 4, when both groups had finally managed to drink their coffees, both groups reported similar levels of enjoyment, satisfaction etc. The difference came in the process. Overall, the group that were drinking the coffee purely for stimulation found the experience of making coffee less pleasant than the group who drank coffee because they enjoyed it. Meaning, those that drank coffee because they liked the taste seemed to enjoy the entire process of making and then drinking the coffee more than those who were just looking for a pick-me-up. Moreover, the ‘hedonists’ also attached more importance to the satisfaction of the smell and the taste of the coffee than did the ‘utilitarians’. Interestingly though, vision played an important role throughout the whole process for both groups of participants.
So how much we enjoy the process of making coffee depends on why we are drinking coffee in the first place. What about you? How do you rate the time that you spend brewing your coffee (I think that we can extrapolate this to tea too)? Are you a hedonist, a utilitarian or somewhere in between and does it matter? Please share your thoughts either here, on FB, or on Twitter.
*The study was performed at the Nestlé Research Centre so presumably used instant, hence the ‘jar’. Does this affect the conclusions of the study for ‘speciality’ coffee drinkers? Are you a utilitarian speciality coffee drinker who nonetheless enjoys the entire process? Please share your thoughts in the comments section below.
It’s nearly 7 years since Kaffeine first opened its doors on Great Titchfield St, but Kaffeine on Eastcastle Street is a new addition having opened just over a year ago. We visited the younger Kaffeine a couple of weekends ago when looking for a coffee in the Oxford St area. Along with an iced coffee, an Americano and a long black, we had a raspberry/cashew slice and a slice of banana bread. It was a relief to find that Kaffeine had a good nut policy so I could confidently enjoy my banana bread, knowing it was nut-free, while a friend devoured the cashew containing slice. The staff were attentive and friendly and there was plenty of space inside to sit and chat while taking in the surroundings. In this regard, it was nice to see this same point being made on Kaffeine’s own website where it says that you can “…sit at the high stools at the massive sun filled front windows and watch the world go by”. With the accompanying coffee, what more could you want? The coffee was, of course, very good (beans from Square Mile), and it was great to see that part of the philosophy behind Kaffeine is to take “the art and science and practice of making espresso coffee to a whole new level”. It’s always a pleasure to see those three distinct, but essential, elements combined. I do however remain unconvinced that many could tell the difference (in a blind taste test) between an Americano and a long black.
The table top at Kaffeine, Eastcastle St.
Complimentary mint-infused water was on offer at the back of the cafe and, although this made the Daily Grindlast week, there was just too much to notice at Kaffeine to make this the subject of the cafe-physics review. Indeed, from the perspective of anyone who wants to slow down and notice things in a café, Kaffeine is brilliant. This cafe-physics review could have been about so many different things. There were the weights holding the door open in a pulley system. The trademark neon sign. The compact-ness of the cashew/raspberry slice or the reflectivity of the copper on the side of the counter. I was in cafe-physics review heaven! So many different mental alleyways to run down and explore as the different bits of physics came into view. From pulleys to Archimedes, cakes to ceramics science, copper to atoms or to the odd puzzle about the colour of gold, all these will have to wait for another time. This time, what struck me was not what could be seen but what could be felt.
Far from going into a subjective piece about the ambience of the cafe, I mean this statement far more literally. The table, with the wooden grain, felt rough. In the middle of the table, a piece of slate had a surface that was more smooth and then, on the walls behind us, highly glazed tiles were very smooth indeed. What do we mean by rough or smooth, how rough is rough, how smooth is smooth and what has it to do with the “magic mirrors” of Japan?
Smooth tiled wall at Kaffeine
The wooden bit of the table for instance has a surface that undulates with a height of the order of about a millimetre. The slate is far smoother but the surface would still be rough, probably on a length scale tens to hundred microns or so (about the size of espresso to medium grind coffee). The tiles are a lot smoother than both the wood or the slate but they are still not so smooth that they could be considered flat on an atomic scale. To be flat on an atomic scale, the surface would have to have a height variation 100 000 times smaller than the smallest particles in an espresso grind*. While some crystals can, naturally, have ‘faces’ that are this smooth, the semiconductor industry needs to be able to achieve this level of flatness routinely to provide the electronics for your smart phones, computers and even perhaps the electronic scales that are used to help you make your coffee.
The mirror-like copper clad counter.
In ordinary life however, perhaps we think that a smooth surface is like that of a mirror. So it is worth taking a look at an odd type of mirror for which very small variations on the surface cause a very strange effect: the “Magic mirrors” of the far East. Typically made of bronze, these mirrors have been manufactured for nearly 2000 years. On the back surface of the mirror is an artwork (perhaps signs of the zodiac or other religious symbols) which is in relief. The front of the mirror meanwhile is highly polished but slightly convex. Looking directly at the front surface of the mirror, there is no visible sign of the image on the back. Maybe you don’t find this surprising, the mirror is solid bronze after all and we can’t see through solid metal. However, if you were to take a step back, shine light on the front of the mirror and look at the reflection of the mirror projected onto the wall, the image at the back can clearly be seen, there in the reflection (you can see photos of this effect here).
Initially this phenomenon was dismissed as ‘trickery’ but subsequent, careful, study showed that small deviations from perfect curvature on the reflecting surface were enough to cause the effect. Although the mirrors were cast and then polished, nonetheless, stresses and strains from the pattern on the back had propagated through the atomic structure that forms the metal and resulted in tiny, invisible to the eye, changes on the front surface of the mirror. Sometimes it does appear that looking at things in a different light can really change our impression of what something is.
Kaffeine can be found at 15 Eastcastle St. W1T 3AY
* Scaling to coffee grind size approximate but based on measurement of grind size reported here.
Mint in a glass of water. Do other species appreciate a mint aroma too?
Very often, in a café, there will be a jug of mint infused water sitting in a corner, offered as a complimentary accompaniment to the coffee. A fragrant way of ‘refreshing our palate’. Mint is one of many aromatic plants that we use to scent our rooms or freshen our breath. But are we the only species that uses mint and similar aromatics such as lavender in this way? Do other animals appreciate the aroma that a freshly plucked mint leaf can provide?
A few weeks ago (in mid-spring in the northern hemisphere), I noticed some odd bird behaviour going on just outside the window. A blue tit (Cyanistes caeruleus) had landed on the edge of a pot of mint and was busy tearing leaves off the plant that was growing just outside. We watched as the bird hopped around to the other side of the pot, tearing off the younger, fresher leaves. What on earth was it up to?
A sprig of mint growing in a pot.
A quick use of duckduckgo (or google if you’d prefer), revealed a surprising answer (or at least further questions) to this odd behaviour. It would appear that blue tits have been observed to pick mint, lavender and curry plant leaves and use them to line their nest. Moreover, individual blue tits have a preference for different plants. Some females (it appears to be the female that collects the leaves) prefer mint, some lavender, and presumably some prefer curry. There is even a video from “Springwatch” that filmed this behaviour in a blue tit nest a few years ago (link is here). Similar behaviour has been observed in some other bird species such as the Starling (Sturnus vulgaris) but not in other, related bird species such as coal tits or great tits. So what could be driving this behaviour, is it, as the BBC said in its headline “aromatherapy”?
According to research, in fragranced nests, the number of bacteria/pathogens on the chicks was significantly reduced compared with non-scented nests. The chicks also seemed healthier, not only did they have a higher red blood cell count, they grew faster. What remains unclear is the reason that this should be so. Is it that the mint is anti-bacterial? Or is it, as suggested in the programme Springwatch, that the smell can perhaps relax the immune system of the birds allowing them to “put more effort into their growth”. Moreover, how did the birds first know how to pick these plants? How did this behaviour spread?
There is always a risk that we anthropomorphise other animals and consider that they appreciate aromatherapy when they are not doing so. There is however an alternative risk that we reduce animals almost to biological automata that manifest different behaviours purely for the biological advantage it gives them (as if they know that in advance). These questions are too far outside my ‘specialist’ area, for me to attempt to consider on Bean Thinking. However, as an ‘interested observer’ I can still appreciate and wonder at the interesting sights that five minutes spent observing our surroundings can provide. I will also enjoy the feeling it brings to know that we are sharing the mint on the window sill with the blue tits and their chicks.
Have you ever observed similar behaviour by birds in your neighbourhood? What birds around the world share our preference for mint? Comments are always welcome either here or on Facebook or Twitter.
