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Allergy friendly cafe with good nut knowledge Coffee cup science Coffee review Home experiments Observations Tea

Coffee chemistry at Estate Office Coffee

Could it really be true that the tables were reclaimed school science desks? I had read a review of Estate Office Coffee by Beanthere.at on London’s Best Coffee that had made this surprising claim (together with favourable comments about the coffee and cakes). Like a red flag to a bull, a visit was inevitable. Would there be any clues left on the tables as reminders of the past history? In the absence of many photos of the interior of the café, my mind wandered to images of long wooden benches like the physics labs in my old school. I imagined enjoying a coffee at such a bench, seated on a wooden stool, my feet not able to reach the ground. So when I arrived outside the cute little building, I was a bit puzzled as to how a whole lab could fit inside! Going in, my images of rows of coffee-table-lab-benches were metaphorically thrown out the window. Instead, a set of modern looking (small) tables were arranged so that several groups of 2-4 people could sit and enjoy their coffee together or individually. A lovely, friendly, space for conversation with friends but not quite the lab I had imagined. The counter, which was on the right as we entered, had a great array of muffins and cakes arranged on it which proved irresistible (and they knew which allergens were in which cake, so a definite tick in the ‘allergy friendly’ café box). The coffee (from Allpress espresso) was also very good and we ‘retired’ to a table to enjoy coffee and cake together.

interior Estate Office Coffee
Clearly science labs have changed since I was at school! The tables in Estate Office Coffee are reclaimed lab benches.

Although warm that day, sitting near the window was a very pleasant way of slowing down and noticing things. Moreover, the local history that is framed on the wall near the door, provided an interesting diversion for understanding how this quirky building came to be (and to survive in its present form). Copies of Caffeine magazine were also lying around adding to the large number of things that you could think about rather than revert to checking your phone. Finally though, curiosity got the better of me and I asked, were the tables really old school science lab benches? The helpful barista wasn’t absolutely sure and so texted the owner to enquire. Fairly quickly an answer came back: yes indeed, the wood had been reclaimed and used to be laboratory benches. Either school science labs have changed a bit since I attended or the tables have undergone a refurbishment as well as a reclaim, but nonetheless what a feature! Together we looked underneath the tables and noticed the parallel grooves running along the underside of the wood. What were they used for? Pens? Drainage channels for spilt chemicals? The mind boggled. But then returning to our table, we noticed that despite the lovely varnish and careful refurbishment, our table showed evidence of previous science lab use. Two circular stains as if the wood varnish had been etched by a strong acid. Immediately this took me back to experiments-gone-wrong with a home chemistry set but then it set off a whole different thought train through a slightly lateral connection to acidity and coffee.

table detail, inside Estate Office Coffee
Evidence of a past life?
Two rings in the varnish on one of the tables at Estate Office Coffee.

The issues and science associated with acidity in coffee have been discussed many times elsewhere and so if you would like to follow that train of thought you can do so here or here. Instead, I was reminded that the Arrhenius definition of acidity was that of a substance that, when in solution, increased the concentration of H+ ions in the water. For reasons that will become clear, this reminded me of stories I had heard of expert coffee-tasters who always use the same spoon when cupping coffee. Were there actually very good reasons that these coffee tasters always insist on using their own, same spoon, in every cupping session?

The connection between acidity and the spoons used for cupping comes via the ability of substances to gain or lose electrons to become ions. In the case of acids, the ion is H+ but different elements form their ionic counterparts more or less easily. This means that it is easier to take two electrons from the element copper (Cu) to form Cu2+ than it is to remove one electron from gold (Au) to form Au+. The ‘ability’ of a substance to gain (or lose) electrons is measured by the standard electrode potential. A few years ago, a group at the Institute of Making investigated whether different teaspoons made from different metals tasted different. In a blind taste test involving 32 participants, not only did they find that the spoons tasted different (as measured by bitter, metallic, strong etc), those metals that were more likely to form ionic species in solution (as indicated by the standard electrode potential) consistently tasted more bitter and more metallic than the rest: copper and zinc teaspoons tasted metallic, chrome and stainless steel tasted the least.

coffee at EOC Streatham
The important thing is how this tastes. What is the influence of cup size, shape, colour on your perception of the taste of coffee?

What was more interesting though was that the investigators then turned to the question: does the type of spoon used influence the taste of a substance? Although they investigated ice cream rather than coffee, the tastes they were looking at (bitter, sweet, salty, sour) are very relevant to coffee tasting. Again, the authors did a study involving a series of blind taste tests, this time involving 30 participants. Again, the teaspoons used were identical to each other apart from the fact that each had been electroplated with a different metal (gold, copper, zinc or stainless steel). Again there appeared to be a dependence between the taste of the substance (ice cream) and the standard electrode potential of the metal used for the spoon. When the ice cream (which had been separately flavoured to be more salty, bitter, sweet, sour or left plain) was blind-tasted with zinc or copper spoons, the ice cream was consistently rated more bitter than when tasted with stainless steel spoons. But there was more, it seemed that the sweetness of sweet ice cream was enhanced by the copper and zinc spoons. Indeed, copper and zinc spoons seemed generally to enhance the dominant taste of the ice cream (sweet became more sweet, salty more salty etc). Although spoons made of these two metals were also rated as tasting metallic, the most pleasant blind-tested ice cream-spoon combination was the sweet ice cream tasted with the copper or zinc spoons.

So it would appear that the material that the spoon is made from could influence our perception of the taste of the food or drink we consume with it. The taste of coffee could be influenced by the type of metal spoon that is used to taste it with. Other studies have emphasised the psychological importance to taste of the appearance or weight of the spoon. For consistent cupping therefore, it may very well be a good idea to stick to your favourite spoon.

However, this seems an area in which anyone can do a bit of kitchen-top coffee science experimentation. Have you blind taste tested several coffees? What about different coffees with different spoons? For those who cup coffee regularly it would be fascinating to hear your thoughts on the influence of the spoon on the taste of coffee. For those of you new to coffee cupping, you can find a how-to at the bottom of this post and then please do share your experiences. In the meanwhile, you may be pleased to return in our imaginative journey to Estate Office Coffee where a great tasting coffee can be enjoyed in a non-metallic cup and where you may additionally pause to ponder the influence of your surrounding environment on the pleasure you derive from your coffee.

Estate Office Coffee can be found at 1 Drewstead Road, Streatham, SW16 1LY

 

 

 

Categories
Coffee review Coffee Roasters General Observations slow

Time for a slow coffee?

enamel mug, teh halia, Straits Times kopitiam
This enamel mug connected glass to the Giants Causeway (Straits Times kopitiam)

Every two weeks, the Daily Grind on Bean Thinking is devoted to what I have called a cafe-physics review. The point of these reviews is to visit a café, slow down and notice what has been going on in a cafe physics-wise. I focus on physics because it is my ‘specialist’ area but the point is to notice the connections between the coffee, or the cafe and the world around us. To see how what is going on in your mug is reflected in the science of the wider universe. Realising that things that seem disparate are in fact connected: It is the same maths that describes electrons moving in a metal and the vibrations on the surface of a cup of coffee. That sort of connection to me is mind boggling. Yet there is more. Thinking about the connections between physics and coffee can lead to meditations on the environment and sustainability, or considerations about how our attitude to drinking coffee changes our perception of it.

Everything is connected.

Parquet floor at Coffee Affair
How many people have walked on this floor? The story of evolution at Coffee Affair

It is my strong belief that whenever we go into a cafe, order a coffee and then proceed to sit down with our smart phones or tablets and check our e-mail or our Twitter accounts we lose a fantastic opportunity. It is the opportunity to be properly present and to notice what is going on around us. It is the opportunity to slow down and to appreciate what life has given us and the surprising things that the world has to offer. To look at the beauty and the complexity of the world and to say ‘wow’.

This appreciation is open to us all, provided we seize the opportunity to slow down and take that time to enjoy our coffee.

So, this week’s Daily Grind is an invitation. It is an invitation open to anyone who sits down with a coffee. If you notice anything peculiar, or interesting, that you feel deserves a mention as a cafe-physics review why not write an edition of the Daily Grind? It does not matter where in the world you are or what your level of science knowledge is. If a full Daily Grind article is too much but you have a great observation, write a paragraph review of your favourite cafe and I’ll add it to the cafe-physics review map. Think that you don’t know enough science? Never mind, share your idea with me and we can work on it together.

Hasten coffee, long black, black coffee, espresso base
Sometimes the link with physics/science is a little bit tenuous, as it was at Espresso Base

Your observations need not be physics-based. It would be great if it is based on some aspect of science, but, as past examples have shown, this link can be a little tenuous if the cafe/subject warrants it.

So, over to you. I hope that someone will respond to this invitation. Please do contact me if you would like to pen a review or if you have any questions. It is my hope that you are all enjoying such great coffee in the huge variety of cafe’s that we now have that there will be plenty of opportunities for people to slow down and to notice and then to share it with the Daily Grind.

Please contact me here, or in the comments section below. I look forward to hearing from you.

 

Some brief guidelines for a cafe-physics review:

1) The cafe should, preferably, be a good independent.

2) Any science/history etc. needs to be verifiable but, as mentioned, if you’ve noticed something great but are unsure of the science, get in touch and we’ll work something out together.

3) If you have noticed something fascinating with your coffee but at home and not in a café, contact me anyway.

4) Please do not write a cafe-physics review of any cafe you are financially associated with. I will have to refuse/delete any ‘reviews’ that I find are adverts.