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Coffee as an art at Briki, Exmouth Market

exterior of Briki coffee London
Briki London on the corner of Exmouth Market

Traditionally made coffee always appeals to my sense of coffee history. Coffee made its way out of Ethiopea via Turkey and the method of brewing the finely ground coffee in a ‘cezve’ or ‘briki’ is one that goes back a long way. It’s therefore always interesting when a new cafe arrives on the scene that offers “Greek” or “Turkish” coffee on its menu. Briki, in Exmouth Market, opened in May last year and so it was only going to be a matter of time before I visited to try it out. Aesthetically Briki appealed to me as soon as I walked through the door. Spacious and with the bar along one wall, there are plenty of seats available at which to slowly enjoy your coffee. The cafe itself is almost triangular and the other two walls have windows running all along them. What better way to sit and enjoy the moment (and your coffee) than to gaze out a window? Still, given that I had gone to a cafe called ‘Briki’ and that it advertised “Briki coffee” on the menu behind the bar, it was obvious that I had to try the briki coffee. The coffee was rich, flavoursome and distinctive, well worth the time taken to savour it. There was also an impressive selection of food behind the counter and the dreaded “does it contain nuts” question was met with a friendly check of the ‘allergen’ folder. I was therefore able to also enjoy the lovely (nut free) chocolate cake. Briki definitely gets a tick in the “cafes with good nut knowledge” box on my categories list.

image from British Museum website
Folio 109b from an album of paintings showing Turkish sultans and court officials. Kahveci. A youth who serves coffee. He is holding a cup in each hand, circa 1620.
© The Trustees of the British Museum

However as I realised later, the coffee was not brewed in the traditional way but in a Beko coffee maker – a coffee maker specifically designed for optimising the brewing of Turkish coffee. The idea of the Beko is that it carefully controls and automates the entire brewing process so that you get a perfect coffee each time. But just how do you make a ‘perfect’ Turkish coffee?

A quick duckduckgo (it’s a mystery to me why has this verb failed to catch on while ‘to google’ is used so frequently) revealed two sets of instructions on how to make Turkish coffee. The first set, (including some otherwise very good coffee brewing websites) suggested ‘boiling’ the coffee repeatedly in the pot (cezve/briki). The second set, which seemed to be more specifically interested in Turkish coffee (as opposed to interested in coffee generally), were much more careful, even to the point of writing, in a very unsubtle way, “NEVER LET IT BOIL“. According to this second set of websites, the coffee in the cezve should be heated until it starts to froth, a process that begins at around 70C, far below the 100C that would be needed to boil it. Warming the cezve to 70C produces these bubbles and the lovely rich taste of the traditionally made coffee. Heating it to boiling point on the other hand destroys the aromatics* that form part of the flavour experience of coffee and therefore makes a terrible cup of coffee.

The contrasting instructions however led me to recall a discussion in Hasok Chang’s Inventing Temperature. Perhaps we all remember from school being taught how thermometers need two fixed points to calibrate the temperature scale and that these two fixed points were the boiling point and the freezing point of water. Perhaps this troubled you at the time: Just as with making coffee in a cezve, just how many bubbles do you need in order to say that the coffee (or water) is ‘boiling’? How were you supposed to define boiling? How much did it matter?

Cezve, ibrik, Turkish Coffee Creative Commons license
Cezve, image ©

It turns out that these questions were not trivial. There is a thermometer in the science museum (in London) on which two boiling points of water are marked. The thermometer, designed by the instrument maker George Adams the Elder (1709 – 1773) marked a lower boiling point (where water begins to boil) and an upper boiling point (where the water boils vigorously). The two points differed by approximately 4C.  So how is it that we now all ‘know’ that water boils at 100C? And what was wrong with Adams’ thermometer? The Royal Society set up a committee to investigate the variability of the reported boiling point of water in 1776. Careful control of the heating conditions and water containers reduced the temperature difference observed between different amounts of boiling. However, as they experimented with very pure water in very clean containers they found that things just became more complicated. Water could be heated to 120C or even higher without ‘boiling’. They had, unintentionally, started investigating the phenomenon that we now know as ‘superheating‘. Superheating occurs when water is heated to a temperature far above its boiling point without actually boiling. What we recognise as boiling is the escape of gas (which is usually a mix of air and water vapour) from the body of the water to its surface. In order to escape like this, these bubbles have to form somehow. Small bubbles of dissolved air pre-existing in the water or micro-cracks in the walls of the container enable the water to evaporate and form steam. These bubbles of gas can then grow and the water ‘boils’. If you were to try to calibrate a thermometer using very pure water in very clean containers, it is highly likely that the water would superheat before it ‘boiled’, there just aren’t the ‘nucleation’ sites in the water to allow boiling to start. The Royal Society’s committee therefore came up with some recommendations on how to calibrate thermometers in conditions that avoided superheating which meant thermometers were subsequently calibrated more accurately and superheating (and improved calibration points) could be investigated more thoroughly.

Perhaps viewed in this way there are even more parallels between Turkish coffee and physics. It has been written that “making Turkish coffee is an art form“. It is a process of practising, questioning and practising again. The Beko coffee machine automates part of the process of making Turkish coffee. When it’s done well though, Turkish coffee is far more than just the temperature control and the mechanics of heating it. There is the process of assembling the ingredients, the time spent enjoying the coffee and the atmosphere created by the cafe in which you drink it. Coffee as art in Briki is something that I would willingly spend much more time contemplating.


Briki is at 67 Exmouth Market, EC1R 4QL

“Inventing Temperature”, by Hasok Chang, Oxford University Press, 2004

*Although these aromatics are part of what gives coffee such a pleasurable taste, they decay very rapidly even in coffee that is left to stand for a while, it is this loss of the aromatics that is part of the reason that microwaving your coffee is a bad idea. A second reason involves the superheating effect, but perhaps more on that another day.


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Hanging out at J+A Cafe, Clerkenwell

Exterior of J and A cafe (the bar is on the other side of the passageway)
Exterior of J and A cafe (the bar is on the other side of the passageway)

Tucked down a little alley, in the back streets of Clerkenwell is the J+A Cafe. Not just a cafe, but also a bar, J+A is a satisfying place to find, particularly if you happen to find it serendipitously. As you head down the alley, the café is on your right whereas the bar opens up on your left. The café is simply furnished, with bare brick walls adorned with a few impressionist paintings. There are plenty of seats at which to enjoy good coffee and home-made cake. Their website suggests that J+A specialise in Irish baking and so we dutifully had a slice of Guinness and chocolate cake with our coffees. Importantly, the dreaded “does it contain nuts?” question was met with a knowledgable answer and without the ‘frightened bunny face’ that I often encounter when I ask this question. J+A definitely gets a tick in the ‘cafe’s with good nut knowledge’ box on my website.

Lights were suspended from the ceiling, connected by wiring that was allowed to hang down, a section of electrical wire held at both ends and freely hanging. While I’m sure that this was done for aesthetic reasons (and certainly it works on that level), such hanging wires are in fact far more than merely pleasing to the eye. Such hanging wires were a mathematical puzzle just four centuries ago. Indeed, these simple hanging wires form curves that are so important they get their own name; they are catenary curves, from catena, the Latin for chain.

lights at J and A coffee Clerkenwell
Between each lamp, the electrical cord formed a catenary curve.

Galileo had thought that a wire hanging under its own weight and suspended at its two end points formed a parabola. A fairly simple curve that is easy to describe mathematically. It was natural for Galileo to assume that these catenary curves were really parabolic. He had earlier shown that objects that fell with gravity followed parabolic paths, and after all, the hanging wires did look almost parabolic. It fell to Joachim Jungius to show that the curve was not parabolic and then to Huygens, Bernoulli and Leibniz to derive the equations determining the form of the curve. Although the differences between the parabola and the catenary curves are subtle, they have profound consequences.

When a chain, or a wire, is suspended and allowed to hang under its own weight, it forms a catenary. Flipping this around, quite literally, a catenary arch will be self-supporting. This means that a vault made of a series of catenaries or a dome that is made into the shape of a catenary will be self-supporting with no need for buttresses. This property of the catenary curve was used by Antonio Gaudi in his designs of the Casa Mila in Barcelona and also by Christopher Wren. The famous dome of St Pauls is not a catenary, but it is not one dome either. It is in fact 3 domes stacked together. The outer dome is spherical (which is weak from a structural point of view) while the inner dome is a catenary. The dome between these two was designed, using the mathematics of the day, to support the impressive outer dome (more info here and here). Wren, was not just an architect, he was also a keen mathematician, there is maths, physics and beauty throughout many architectural designs.

Mathematics in the city reflected in the lights of J+A.

J+A is at 1+4 Sutton Lane, London EC1M 5PU


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Gravity and Grace at the Wren cafe

Wren cafe, St Nicholas Cole Abbey
Inside the Wren cafe

There is a lot to like about the Wren cafe. Firstly, there is the space that it occupies (inside St Nicholas Cole Abbey). I went at lunchtime when the way that the light came through the stained glass windows made the cafe a very relaxing and open space. The coffee is from Workshop, complementary water came in 3 flavours (mint, cucumber or lemon) while the food is cooked on site. This is important because it means that they have a great nut policy and could tell me which dishes were likely to contain nuts etc. A further nice feature of the lunch menu at the Wren was that you could select your portion size. Food waste is a major issue for our society and is not helped by the ‘one size’ portions served at many food outlets and cafes. Lunch was offered in two sizes (technically as a side or a main) but the ‘side’ was more than adequate for a mid-week lunch. Sofas in the corner of the room meant that you could relax and take in your surroundings in a comfy environment or, if you were just there for lunch, ordinary chairs and tables were dotted around the room.

Of course, a place such as this will have plenty of things to notice about it. Whether your interest is in architecture or science, there is plenty to observe around you. What I would like to focus on though is a bit of science history that connects the name of this cafe with Isaac Newton, John Theophilus Desaguliers and the dome of St Paul’s Cathedral (which you can see from the front of St. Nicholas Cole Abbey).

View of the Dome from the cafe
The Dome of St Paul’s, visible from the side of the Wren cafe.

Perhaps we all remember the story told to us at school about how Galileo dropped two balls of different mass from the top of the leaning tower of Pisa. According to the story, the balls fell to the earth at the same time, thereby showing that the acceleration due to gravity was independent of the mass of the object and paving the way for Newton’s theory of gravity. Sadly, it seems that Galileo may never have actually performed the experiment (even if it was “re-created” in 2009). However there is evidence that Isaac Newton did perform exactly this experiment in 1710 from the dome of the soon-to-be-completed St Paul’s Cathedral.

“From the top of St Paul’s church in London in June 1710 there were let fall together two glass globes, one full of quick silver [mercury], the other of air”¹. The globes fell 67m before shattering onto the cathedral floor (I’d hate to have written the risk assessment for that experiment). To avoid the possibility of human error, a trap-door mechanism had been designed to ensure that both globes dropped simultaneously. According to the story of Galileo told to us at school, we can calculate how long it would have taken those globes to drop to the floor: 3.7 seconds, independent of mass. So is this what Newton observed? No! The heavy glass globes took 4 seconds to fall, but lighter ones took 8-8.5 seconds! A few years later and Desaguliers repeated the experiment from slightly higher in the dome (but this time with hog’s bladders rather than glass) and obtained the same result.

View of St Paul's Cathedral London
Another view of St Paul’s. Hard to believe that Newton actually dropped liquid mercury from the dome.

This surprising result can be explained when we realise that Newton was investigating not gravity, but air resistance. While the gravitational acceleration is independent of mass, the upwards force due to the air resistance depends primarily on the object’s size (and velocity). This means that the deceleration caused by the air resistance will be different for two globes of the same size but different mass (Force = mass x acceleration). Heavy objects will fall faster in air (until the objects reach their terminal velocity).

There is a certain irony in the fact that this result is opposite to what we feel should happen based on what we learned at school of Galileo’s experiments challenging the scientific orthodoxy of the time. However the result of Newton and Desaguliers’ experiments do not contradict the theory of Newton or Galileo, they just add an extra layer to the problem. We do not exist in a vacuum, we need to think about the air around us too.

Both Newton and Desaguliers were regular coffee drinkers albeit at different coffee houses. Desaguliers frequented the Bedford Coffee House in the north east corner of Covent Garden while Newton regularly retired to the Grecian in Devereux Court (just off Fleet Street). Coffee houses were places that the latest science, politics or philosophy were discussed and debated. The Wren describes itself on its website as existing to “serve the ministry of St Nick’s talks“. Sadly I experienced no discussion or debate on my visit (just a very nice, but solitary, lunch and good coffee) but it is interesting to see the tradition of the 17-18th century coffee houses continued in this Wren designed church and cafe.

The Wren cafe can be found inside St Nicholas Cole Abbey, 114 Queen Victoria St. EC4V 7BJ

[1] The Dawn of Fluid Dynamics, Michael Eckert, Wiley-VCH (2006)

Coffee house info: London Coffee Houses by Bryant Lillywhite (pub. 1963)

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Thinking of foraging at Damson & Co

Damson and Co, like its wild counterpart, easy to miss
Damson & Co on Brewer St.

At approximately this time of year, it is possible to start foraging for damsons in the UK countryside. These small plums make lovely cakes and muffins and, very importantly, great damson gin. A bit like sloe gin but, in my opinion, better. All this is a digression. When I found out about a cafe called Damson & Co I had to try it, purely for the name which brings back fond memories of country walks and gin shared with friends. However, even armed with its address and location on a map I missed it! Damson & Co is very inconspicuous in the way that it is situated on the street. Just as with its wild counterpart, it is easy to walk past without noticing that it’s there but once you’ve seen it, it is obvious, a location that you mark down in order to return to it again and again.

Inside, lavender decorated the table tops in the small but extremely friendly cafe. We enjoyed an Americano, an iced latte and a lovely chocolate brownie that had been warmed almost to the point of melting. They were also extremely helpful when I asked the dreaded “does it contain nuts?” question, checking the ingredients, informing me of the (obligatory) “it may have had contact with a nut at some point in its manufacture” line, but ultimately helping me to choose what was a great nut-free cake. Complementary water was automatically put onto the table and so we had, for the brief moment before I ate the cake, a range of ‘phases of matter’ on the table. Water in the forms of liquid in the bottle, solid ice and steam rising up from the coffee and a brilliantly gooey, viscous chocolate cake somewhere between liquid and solid. At that point it was quite clear what the physics bit of this cafe-physics review would have to be: phases of matter and phase changes.

interior of Damson & Co
Lavender in a jar with sugar in the window of Damson & Co

As ice melts into water, or evaporates to form steam, it undergoes many changes in its properties: Ice is of course solid; liquid water conducts heat much readily more than steam (more on this another day). Another property that changes is the heat capacity of the ice/water/steam. The heat capacity is the amount of energy that it takes to heat a substance by one degree in temperature. At the temperature that the substance changes, say between a liquid and a solid, there will frequently be a spike in a plot of “heat capacity” vs. temperature. This tells us that, as the solid changes to a liquid (or vice versa) the response of the material to being heated changes. Physicists often measure the heat capacity of substances to see if any phase changes occur. A phase change does not necessarily mean that the substance goes from liquid to solid or to gas. A substance will be said to undergo a phase change if it becomes ferromagnetic (like iron at room temperature) or if it becomes superconducting (like aluminium at approximately -272C). Back in the 1920s it was the investigation of the heat capacity of liquid helium that helped to suggest that there was a new form of matter lurking at extremely low temperatures.

Heike Kamerlingh Onnes (a great physicist and apparently a very nice man) had managed to liquify helium gas in 1908. Helium gas becomes a liquid below -269C. By the 1920s it was clear that something very strange happened to liquid helium if you cooled it even more, to temperatures below -271C. The behaviour of the heat capacity spiked indicating that the helium was undergoing another phase change, but to all appearances it was still a liquid. There was no indication that the helium was solidifying, what could it be? More experiments revealed that below -271C the helium liquid started to behave very strangely indeed. It climbed up the walls of its container ‘by itself’ and it managed to leak through minuscule cracks in the glass containers that it was kept in (for a video click here). Cracks that could not be detected before the ultra-cold helium started to leak through them. It took until 1937/38 before this new state of matter was named and it is still not clear that we understand it.

There is so much more to the phases of matter than meets the eye while watching ice melt in a glass of water on a hot summer’s day.

Damson & Co can be found at 21 Brewer St. London

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Diamonds are forever at Violet, Hackney

the outside of Violet
Violet in Hackney

Violet is not quite where I expected it to be. I had expected it to be in a row of shops on a main street, instead it is tucked away, a little cafe in a back street in Hackney. Despite the relative anonymity, Violet has won awards for the quality of its cakes. Award winning cakes are hard to resist and so, a few weeks ago I went along to Violet to try the coffee. With a couple of seats outside and a large room upstairs with seating, it is very easy to enjoy a good coffee and a cake while taking in the surroundings. The cakes certainly do not disappoint and, importantly for Bean Thinking, they know exactly what goes in them, meaning that if you are allergic to nuts or have other food allergies or intolerances, they are incredibly helpful. They definitely get a tick in the “cafe with good nut knowledge” category.

As it had been raining when we tried Violet, we decided to take a seat upstairs. Stacked in one corner of the room were a set of wooden chairs, reminiscent of those chairs that we had to stack at school. Each chair fitted almost exactly onto the previous one. At the top of the stack of chairs however, the uppermost chair did not fit exactly onto the previous chair, it was as if there was a defect in the stack.

stack of chairs, Violet
The chair stack in Violet.

The diagonal legs of the chairs resembled the multiple strata in a layered substance such as graphite. Each layer of graphite features a hexagonal arrangement of carbon atoms forming a structure very much like the chair legs in the chair stack. Graphene, a material of which there is currently a lot of hype, is a single layer of graphite. The carbon equivalent of one chair leg on its own. Carbon is a fascinating element. If, rather than being arranged in layers, it is arranged into a more 3D crystal structure, then you get diamond, a colourless, extremely hard crystal structure, very different from graphite. It is in diamond that defects in the stacking structure (such as with the uppermost chair) can cause spectacular effects.

If the carbon atoms are arranged into a perfect crystal structure, (the equivalent to the chairs being perfectly stacked), then diamond is colourless. If on the other hand, something happens to disrupt the structure, perhaps there is one carbon atom missing in the structure or maybe another, impurity element, such as nitrogen, has got in, the way that the electrons in the diamond react to light changes. This means that it can take on a colour. The introduction of nitrogen for example, in concentrations of only 0.1% will make the diamonds more yellow or orange. Red diamonds are a consequence not of impurities but simply defects in the crystal arrangement. The equivalent to that one last chair in the chair stack changing the properties of the stack completely. Knowing that the colour of a diamond is a result of a defect in the arrangement of carbon atoms in the structure offers us two possible viewpoints. Either people who buy red diamonds are paying a premium for defective goods, or, beauty takes many forms and what is beautiful is not necessarily what is regular and perfect. I know which view of the world I prefer to take.

Comments are always welcome, please click in the box below.

Violet is at 47 Wilton Way, E8 3ED

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Crystal Perfection at Workshop, Holborn

Workshop coffee Holborn
Diamonds are forever, Workshop coffee Holborn

The brand identifier of Workshop coffee is a diamond, a representation of which hangs on the wall as soon as you enter the Holborn branch. I had arrived at Workshop in order to try their coffee after I’d had a great espresso made with beans roasted by Workshop at Knockbox in Lamb’s Conduit Street. The coffee brewed in their own café certainly did not disappoint. I enjoyed a very good La Soledad filter coffee and a cake (which was confidently nut free, this brings me to another plus point for Workshop, they know the ingredients of their cakes!). The interior of the cafe, just beside Holborn Viaduct, is quite spacious and, if you sit at the back, you get a great view of the workings of the espresso machine as different people come in to get their ‘take out’ coffee. It is very possible to spend quite some time here in order to relax and enjoy your coffee while taking in your surroundings. To a physicist who studies materials (like me), the diamond logo of Workshop represents a fantastic material. A material in which the structure of the crystal determines so much about its properties. Were the carbon atoms in diamond bonded slightly differently, they would form the soft, pencil lead material ‘graphite’, rather than the hard, transparent material of diamond.

unit cell, repeating structure
The floor at Workshop reminds me of my crystallography text books.

Whether it was intentional or not, the crystal theme of the logo was replicated in the floor tiling of the Holborn branch. Crystallography is a branch of science that probes the building blocks of solids. It reveals how the atoms that make up different solids are arranged to form the solid. The atoms could be arranged in a simple cubic arrangement (as with salt) or hexagonally (as is the case for graphite). To establish the crystal structure you need to find the smallest repeating unit in the whole. Many introductory solid state physics or crystallography text books use 2D examples of repeating structures to help the student to understand how to build up these “unit cells” into full blown crystals. Many of the examples of such lattices look stunningly similar to the floor at Workshop.  Fundamentally, the idea of the crystal is that it is a simple repeating structure, just like the floor of Workshop. Indeed, the word “crystal” as used by Pythagoras implied perfection, harmony and beauty, a sense that is really conveyed by the crystal structure of the diamond logo of Workshop.

Crystal cake, LaFeSi cake, grape atoms
When a colleague left our lab, we made her a  cake that was a representation of part of the crystal structure of the material that she had worked on. Chocolate grapes and profiteroles represent different atoms in the structure.

The ancient Greek term for “crystal” actually implied the type of hard ice that is wonderfully clear and transparent. And it is ice that connects the area surrounding Workshop with a famous chemist who won a Nobel prize for his work in crystallography in 1962.  Max Perutz (1914-2002) described crystallography as a technique that “explains why diamond is hard and wax is soft, why graphite writes on paper and silk is strong”. Once you have enjoyed your coffee at Workshop, if you head down the stairs on the viaduct and descend to Farringdon Road you quickly get to Smithfield Market. It was here that, during the Second World War, Perutz helped to develop the material Pykrete. A “secret weapon” of World War II, Pykrete was developed five floors below Smithfield Market in a room cunningly disguised with animal carcasses. The planners in the war effort had wanted to design a boat made of ice but the problem was that when it was shot at, ice shattered. Could scientists develop a type of ice that would not shatter if it got hit by enemy fire? Pykrete was the answer. Pykrete uses the fact that materials such as plastics can be strengthened by adding fibres to them. In the case of Pykrete the “fibres” were sawdust and the material to be strengthened was ice. Not only does it not shatter when shot at (instead, the bullet creates a crater in the ‘boat’), it takes a lot longer to melt than ordinary ice. The sawdust encased in the ice acts to insulate the ice and increase its longevity.

Perutz’s Nobel prize was for his work to determine the crystal structure of haemoglobin, it took ‘just’ 25 years to do so. The field of crystallography continues to enrich our understanding of the behaviour of solids, though now we’re expected to get results more quickly than the 25 year time frame Perutz enjoyed. If you know of a good café where lots of physics goes on, or of a good café near a site of special (or unexpected) scientific interest, (or even just a good café) please do share your story either in the comments section below or by contacting me on email, Twitter or Facebook.

Workshop Holborn is at 60 Holborn Viaduct, EC1A 2FD

Quotes and other useful facts taken from:

In our time, 29th November 2012: Crystallography“, (BBC Radio4)

Max Perutz “I wish I’d made you angry earlier” (2002),

Ichiro Sunagawa “Crystals, Growth Morphology and Perfection”, Cambridge University Press (2005)

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Spinning a yarn at E&J’s Pantry, Endell St.

E&J's Pantry on Endell St
E&J’s Pantry on Endell St

There are still a few areas of central London which seem a little short on good cafés. One such area lies just east of Covent Garden. So it was very fortunate that, on arranging to meet a friend nearby, I came across E&J’s Pantry on Endell St. The coffee is from Nude roastery and the interior, while not exactly spacious is large enough that we were able to sit undisturbed for quite some time. Along with good coffee, they serve lovely cakes which (according to their website) are made in their own kitchen. This is presumably why they could tell me confidently which cakes were nut free. (Those who follow @thinking_bean on Twitter may know that this is a bit of a hot topic for me.) I enjoyed a very good Long Black and a cake, before sitting back and taking in the surroundings.

On one of the walls inside E&J’s Pantry are a series of photographs. Each photograph is suspended by a thin thread from a rail near the ceiling. The observation reminded me of spiders webs and the (often heard) claim that spider silk is a natural material that is “stronger than steel”.

photographs, spiders web, nylon
Photographs inside E&J’s pantry. Can you see the thin threads holding up the pictures?

Unfortunately, the claim that “spider silk” is stronger than steel is a little disingenuous. For a start, there are many forms of spider silk. A ‘typical’ orb spider for example, will combine at least four types of silk to make a web. Secondly, even for the main type of structural silk (Major ampullate), the statement that it is stronger than steel is sadly pushing it a bit. The issue is that it depends on exactly how you define ‘stronger’ and the species of spider that makes the silk. Spider silk can be comparable to steel in terms of its tensile stress (how much it takes to break it), but it is when it is compared to steel based additionally on the weight of the material that spider silk can be considered ‘stronger‘. When you combine this with the fact that spider silk is more environmentally friendly (and biodegradable) than man-made comparable fibres such as Kevlar, it is clear why research is being done into understanding, and synthesising, spider silk.

A question arises. If it is so strong and so lightweight, why don’t we farm the spiders to harvest the silk? Wouldn’t this be quicker than trying to synthesise it? Clearly we weren’t the first to think this and a farmer in North Carolina, USA, tried in the 1930s. Unsurprisingly, there were issues. Firstly, it took 57000 spiders to produce 0.45 Kg (1 lb) of spider silk. Secondly, if they weren’t kept in (expensive) solitary confinement, they ate each other. It seems that the N. Carolina spider farm was not a commercial success. However, as described in the New Yorker (8th Feb, 1941), a certain Miss Mary Pfeifer did harvest spider silk in the first half of the twentieth century, for use as cross hairs in targets for surveyors and, more sinisterly, bombers. Glass engraving at the time was not fine enough for making the cross hairs. The thinnest line that could be made by a diamond cutter into glass was about double the diameter of the silk from spiders webs and so spider silk had an obvious ‘niche’ market.

HM Ng, spider on web
It takes several types of silk to spin a web. Image © HM Ng

In 1941, Pfeifer would pay “small boys” from the neighbourhood 15 cents for each useable spider that they caught and brought to her. She would then harvest the silk and wind it onto spools ready for use in target sights. Since then we have developed nanofabrication techniques which mean that very thin strands of metal (such as platinum) can be positioned onto the lenses. Continuous strips of metal of around 10 nm thickness (this is one thousandth of the width of a spider silk) can be routinely deposited. Through the development of these and similar manufacturing techniques we no longer need spider silk for use in cross hairs. It is probable that the market cornered by Mary Pfeifer no longer exists.

Spider silk however remains one of many areas where, by studying nature we get clues as to how to overcome various technological challenges. Sometimes devices possibilities are obvious, such as with the opportunity of synthesising material with the strength to mass ratio of spider silk. Sometimes however devices are a long way off. It would be a shame if we prioritised research into devices at the expense of appreciating the ingenuity of nature’s own solutions to its problems. As the story of Mary Pfeifer shows, sometimes today’s obvious devices are not those of tomorrow, who knows where research done purely out of curiosity would lead us.


E&J’s Pantry is at 61 Endell Street, WC2H 9AJ

More information about spiders webs can be found in “Spider Silk”, L Brunetta and CL Craig, Yale University Press, 2010