Monthly Archives: February 2015

Remarkability and Game Mechanics

A book about word of mouth, trending, and all round contagiousness was fittingly passed on to me by a customer of ours recently.

I really enjoyed reading this book, and felt myself saying “Yes, that’s exactly what happens” on almost every page I read. Needless to say I highly recommend the book, and this blog is about a few but not anywhere near all of the concepts and ideas explored in the text, which is Authored by Jonah Berger and titled Contagious.

The book looks a lot at social currency and influence. Using psychology and statistical research to build a comprehensive guide as to why some things catch on and why others don’t.

Two concepts that struck a particular cord with me are those referenced in the title of this blog.

Remarkability, commonly defined as “notably or conspicuously unusual; extraordinary” & “worthy of notice or attention”, is in many ways flowing through the veins of speciality coffee.

The pursuit of character and flavour in coffee is all the more remarkable when juxtaposed with its more commoditised counterpart.

This presents an alternate positive perspective in regards to serving coffee, swapping the notion of restriction and lack of meeting expectation for that of increased Remarkability. For example, a speciality coffee that works solely as a black filter and struggles to be personalised and manipulated in the common way could be seen as a failure to meet customer demands, but on the flip side also has the potential to be remarked upon. All of this of course depends on framing and presentation. But questions of ‘why’ begin. “Why doesn’t it do what most other coffee does? Why does it taste floral, you have to taste this coffee it’s so interesting, I never knew coffee was so complex” and so on. The Remarkability can cascade from here. After all, there is so much that is noteworthy.

Of course, there is potential for much Remarkability in more commercial settings, it just changes nature. The sharing or the noteworthy element may be more about the seasonal concoction or the new loyalty scheme.

Speciality coffee on the other hand has this kind of natural Remarkability, and it’s this very aspect that made me want to work with it and start a company based around it. In fact that shareableness of coffee’s Remarkability is at the core of our concept. We often get asked whether we were concerned about doing things differently. Taking a risk etcetera,  we honestly didn’t think about it. We believed in the Remarkability of speciality coffee and in the concept of making that Remarkability more visible. We struggled to see how that couldn’t catch on, how that couldn’t connect with an audience.

It is intriguing that the talking points of coffee that allow it to stand out are often covered up in an attempt to make it more approachable. The danger with this, clearly, is that the excitement, the word of mouth power can get lost.

Of course, unusualness and extraordinariness are relative. A coffee with bright acidity and sweetness is in the larger scheme of things pretty rare, but when immersing oneself in speciality coffee for a while, these can become somewhat normal. The goal posts change. This isn’t a concern for speciality coffee, as the rabbit hole is endless. The drinker just becomes a player in a complex and engaging game, one that benefits from repeat rounds.

This leads nicely into the concept of game mechanics. Game mechanics are everywhere in our lives, sometimes in surprising places. They can be part of the conversations we have and the topics we interact with.

In service businesses we can find these game mechanics all over the place. In fact if you as a member of staff can recognise the rules of the game, the job can move from mundane to rewarding, because you can become a player in a number of games. This is dependent on specific environments and structure. For example there’s nothing more frustrating than learning a set of rules and those patterns changing for no apparent reason within the construct of the game. This could be witnessed in a management decision within the business, but also by a customer whose participation doesn’t stick to the rules of the game they thought they were taking part in. This could be because rules weren’t clearly laid out or understood or because the business doesn’t consistently deliver.

Barrier to entry presents an interesting question regarding both game mechanics and exclusiveness. Flavour notes provide all sorts of game mechanics. But can seem overwhelming and exclusive. This barrier to entry is often discussed in speciality coffee. We want everyone to take part, but can forget that we are committed players.

Take two games as an example. Articulate and magic the gathering. Articulate has a low barrier to entry. The concept is pretty intuitive with lots of potential complexity. Magic the gathering however requires a player to learn quite a lot. The rules and dynamics are more complex and less intuitively understood.

We have all sat down to play a game and thought ” I’ve got no idea whats gong on”. The truth is we are all capable of understanding the rules and taking part. But do we have the time and inclination to initiate ourselves with the game, such as would be the case with Magic the Gathering?  The same question could be asked of speciality coffee.

Speciality coffee is intriguing in that it presents layered levels of entry and education. It’s easy to taste coffees and see what you think, but of course many people may have no interest in entering a flavour dynamic with a barista as host. If the choice is made, the depth of the game can expand quickly beneath your feet. The drinker can begin to learn more tasting language, to draw links between processing and flavour. On the other side of the counter , brewing itself presents a barista game theory. Getting better at brewing, better at tasting, better at the coffee game is something we all strive for, it’s part of the craft. The game here can be more practical, in a commercial environment, speed, cleanliness and service present a constantly malleable and challenging game dynamic. Busy service never gets boring.

Remarkability and game mechanics raise interesting questions about accessibility. Perceived exclusiveness can be a good thing as the topic or game may be more notable and shareable. Ironically, types of exclusiveness could increase accessibility and popularity.

We hit a big audience in store. But its fair to say most visitors still feel like they are privy to something special, a game for connoisseurs. Luckily for us, being a spectator to that world, dipping your feet in, appeals to a lot of people. Many take up the game, others enter the profession, and many watch from the stalls. Importantly though, people want to talk about it.

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The Heat is On – More Grinding Puzzles

The reaction to my last post indicates the sheer amount of interest in grinding concepts. It has also presented me with some completely new and surprising information. Out of all of the concepts and speculation put forward within the article, it was actually a seemingly well-established and widely accepted idea that sparked debate.

Let me summarise:
As we get busy the grinder gets hot and we find that we have to adjust the grinder to a finer setting to achieve a similar extraction to what we initially dialled in, earlier that day. Without going finer, the flow rate of the shot speeds up, with the recipe of dose to shot weight kept the same. Every barista around the world will have worked with this day to day, frequently being irritated by the circles they find themselves running round in.

There are two main theories that are circulated to explain this phenomenon. That is i) the heat of the grinder expanded the metal composition of the grinder and that the burrs move apart or ii) possible change in efficiency of the grinders motor as it beds in for the day.

The world of twitter comes into its own here, allowing for quick, albeit short and sometimes confusing conversational exchanges. Some people questioned, quite aggressively, this notion regarding heat and grind changing. In fact, it was implied to not be true at all: This is very intriguing, because if this is the case, then we want to know why!

It appeared that this knowledge is coming from research carried out by grinding manufacturers; proprietary studies where the results are often not public. But, if the studies are true; that is, the grinder is not changing, nor is the particle sizes coming out of the grinder, the ramifications are massive.

If the grind doesn’t change then some other change is having a huge impact.

The popular counter argument is that hotter grind results in hotter puck temperature. That the grind stays the same and heat energy changes flow dramatically. For instance, yesterday in store we had a medium busy day and we had to alter the grind dial on the EK43 approximately one whole number by midday to achieve the same flow rate that was achieved in the morning. If the grind is not changing, we have then made our grind a hell of a lot finer. This means that the mode of all the particles in the puck is smaller: we will have dramatically changed the surface area within the dose, the contact time will be similar as we have kept the flow the same by going finer. This means our extraction should be considerably higher in the afternoon compared to the morning.

This would then mean that every shop carefully adjusting their grind to achieve a consistent recipe all day long have got it all wrong, myself included. Being proven wrong is a good thing, if it helps us have a better understanding of what we are doing.

It would actually mean that we need to let the flow rate speed up during the day in acknowledgment of the grind size/surface area being the same. It raises some other questions though. Is the increased heat and its potential impact on extraction counter acting the decreased contact time from a speedier flow rate? Or would we need to slow it up, but just not as much as we do.

In all honesty I haven’t consistently tested the extractions at the lowest and peak busy times in store. We have tested it at various times and not noticed a dramatic correlation, but we haven’t steadily tested it with a good data set. I have a coffee post lunch every day though, a coffee I drank in the morning and at the same recipe, it is often a little different but it tastes good. I may not be picking up on something though, which is always a sensory concern. Would the extraction really stay the same if I kept the weights of the dose and shot the same but let the flow rate go as it pleases? One comment on twitter suggested that this new understanding led the individual to actually go coarser in the busy period to counteract the posited increased extraction from a hotter puck….

Wait a minute… what are we talking about? I am now confused. The grinder is not physically changing aperture with temperature, yet I am grinding a lot finer to achieve the same extraction when the grinder is hot. And you are telling me that I the particles coming out of the grinder are not changing in size or distribution as the temperature increases, yet the flow rate suggests otherwise?

Something is fishy here.

The source

The problem with this discourse however was the lack of source material/data. We needed to see the data that the grinding companies have obtained. Grind distribution graphs can look hugely different depending on what axis have been used (i.e. log scales, volume %, total count, etc) and because a lot is going on at once the interpretations can be troublesome. As mentioned in the last post, changing the axis from volume % (where fines are minimal contributors because they are very small) to surface area % (where fines have a huge surface are to volume ratio and thus contribute massively) completely changes what we see as significant. The fines bump which looks so small and uninteresting in the volume % presentation, becomes the most important part of the graph. They contribute the most to surface area and extraction. Not by a little bit. By A LOT. They are 70% of the grind, minimum.

Myself and Chris were kindly sent the graphs which were at the source of the theory that grind distribution does not change with temperature. They are fascinating, and although I want to present that data here, I will not yet, because we want to write this story concisely and scientifically.

However, I will explain our interpretation of this graph whilst referencing the ideas outlined above.

The first amazing thing that they indicate is that yes: The burrs don’t move apart during the day/heating. BUT they also do not show that the grind stays the same.

Part of the grind stays identical, but part of it changes.

The larger particles and therefore the mode stay the very similar. This is expected, because if the aperture of the burrs remains constant, the large particles coming through should also. So what’s changing? Again, it appears to be all about the fines!

The general shape of the particle distribution is pseudo-Gaussian. It looks like an ant hill. However, the hot grind and the cold grind have slightly different shapes. The tails (the fines) of the cold grind are about twice the volume % of the fines tails of the hot grind.

It means the cool dose produces way more fines and therefore more surface area (slower shot) and the hotter dose appears to produce far less fines and therefore less surface area (faster shot) even though the mode is similar (statistically the same). So in essence the original idea about the grind changing is right, just not for the reason we thought. The burrs don’t move, but the coffee breaks up differently.

Why is this happening?

Chris describes it like spaghetti, a hard cold piece of spaghetti shatters into more uneven pieces through being brittle. When heated, the hotter piece of spaghetti (without added water) is more malleable and less likely to splinter into tiny bits. This actually holds true for just about every organic material. This is well founded and published in Physical Review Letters (the premier physics journal);

It looks as though hot ground coffee is less likely to produce fines. Amazing!

This means when we change our grind to finer we are making more fines to make up for the fact the hot burr ground coffee produces less fines. This will of course change the whole grind profile as we have to bring down our mode size to achieve this. That would infer that a grinder running hotter all the time would be more consistent.

It doesn’t mean we can conclusively say heat of the puck isn’t also affecting flow rate and extraction, but we can say that the grind profile does change at different heats. Chris would speculate this affect is not a major contributor to the extraction.

There we have it, when I wrote that blog and posted it yesterday I didn’t conceive nearly all of which is written above. Thrilling really. May the search for answers continue.

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Grinding – The Dark Matter of Coffee – A Think Piece

There’s a lot we know about grinding. Grinding finer helps us extract more, grinding more coarsely speeds up the flow rate of an espresso. We know that a hot grinder under heavy use changes the grind size and the quality of the bed of ground coffee. The analogy of the title, however, refers to everything we don’t know. The results we can taste, watch and log, but which we can’t fully explain or understand, much like dark matter. And in some cases we question whether or not the ideas we’ve posited even exist. In fact, this analogy carries nicely across a lot of concepts in coffee. We can infer something’s existence and its significance on the quality of our coffee. We can taste the difference, in some cases we can attain more evidence to support and improve our understanding of the difference we taste. But at other times we are left to try and draw correlations and causation from anecdotal evidence and speculation. All concepts start their life speculatively and become stronger and more tangible if they can be tested and proven. The nature of a lot of our thought about coffee means that we change our thinking regularly as we test ideas and find them to be unsubstantiated.

The pursuit to perfect coffee and to understand what goes into it illuminates different elements for us to investigate, with certain elements attracting more attention and consideration at different moments in time. Grinding is definitely a ‘hot topic’. Moving beyond a time where all the equipment chat was mostly about a gleaming hot water dispenser, all be it a very advanced and beguiling one. It is increasingly recognised that the grinder is at the heart of coffee preparation and its arguably the biggest tool at the Baristas disposal.

For a long while I have been under the impression from industry wisdom that a more uniform grind size was the goal, we believed that the narrower the bell curve the better the extraction as it is more even and predictable. But we also knew that because roasted coffee is quite brittle, that it will likely break to produce tiny fragments, fines, and slightly bigger pieces, so-called boulders. I remember watching a fascinating presentation by David Walsh where he employed a unique approach to solving this problem. He soaked beans in water before grinding them to achieve a less brittle bean and then ground the coffee to a more even distribution. I don’t know if he actually achieved a completely uniform distribution, I’m sure it was more even, but it would be interesting to know if it was all, for instance, 100 microns.

His conclusion as far as I interpreted it, was that this changed everything, so much so that the coffee didn’t taste like itself. Extraction percentages that we see as correct or desirable become possibly less relevant as the base from which the number was derived from has dramatically changed.

The starting point for the consideration of what grinding means is rooted in our understanding of solubility, of how the water extracts compounds (and the resulting flavour derived from these) out of the coffee and into the resulting solution- a cup of coffee. Voila

The logic being that the compounds and resulting flavour groups are extracted in 4 speculative groups, each group decreasing in solubility. The first, most soluble fraction, being fruit acids(light weight acids) and organic salts, closely followed by Maillard derived light aromatics. Third would be sugar browning by products and lastly heavier organic matter, usually these taste woody, toasty and heavy etc.

Following on from this we can then surmise that an under extracted coffee suffers sensorially as we have an imbalance of more first group flavours versus less last groups and vice versa for over extraction.

This understanding is in my opinion at the core of brewing good coffee. With the barista trying to understand and utilise how all the variables affect this extraction.

It then follows that a dose made up of big pieces (boulders)of coffee will likely under extract and a dose made up of tiny piece of coffee(fines) will over extract. Therefore a dose of varying sizes will – all else remaining constant- result in varying types of flavour extraction making up the total extraction. The question of what constitutes a boulder or a fine is not clearly answerable. At least I don’t think it has been defined. Is a fine anything under 90 microns(a micron being1/1000 of a millimetre) and a boulder 120 micron and up, is there an in-between of normal grind’s?

The fines will extract more easily and the water will be more likely to move through all groups on a fine. Whereas the boulder will extract less speedily during the same time/conditions, relative to its weight. The extraction must then be stopped before the fine moves on to giving up unpleasant heavy compounds.

A narrower range of distribution should then allow you to hit a higher refractometer reading and retain a well extracted flavour.

All else constant, we would assume that this should allow us to brew identical flavoured coffee made with exclusively fines or exclusively larger pieces/boulders and achieve a similar extraction through modulating extraction time whilst maintaining the heating energy. Theoretically you should have extracted both coffees to the same point in term of dissolved solids and the evenness of the particle size is the defining characteristic as opposed to the size itself.

So far, so good.

But, what if difference size grind particles act very differently to each other during the extraction?

There are a lot of other possible questions to consider, that go beyond this. The above explored concepts assume a lot about the physical properties/nature of different size grinds within a single dose. It assumes the particles have a uniform chemical composition. But what if certain organic structures in the bean are more likely to produce a fine or boulder? Then a grinder that produces less boulders could make the organic material more likely to become a boulder more soluble by breaking it up more. This may or may not be true…. And requires a few experiments, which we hope to do. This blog is a think piece and some of this will prove completely incorrect.

It is more likely, I think, that the difference between grind sizes dictates the heat transfer properties of particles. For instance, smaller particles reach uniform heating before larger ones. This increases the accessibility of dissolving the group 3 and 4 compounds because their solubility is dramatically affected by temperature. How different is this heat difference for larger coffee pieces? Well it is defined by the relationship between volume and surface area. Small bits have a very high surface area to volume ratio, big particles have a much smaller ratio, so predicting how these particles interact with temperature is challenging. Temperature of extraction has, as we know, a huge impact on flavour, look at a cold brew extracted to the same TDS reading at the same ratio as a hot brewed coffee.

If this is happening, then the most desirable grind isn’t just a narrow distribution of grind size, but its possibly a narrow distribution of a specific size of grind, one that provides an optimum heat transfer and resulting type of extraction. This would mean a desired brew time as well. For example, if a small size was best, then brew times would need to stay short and a different recipe that achieves the same extraction with a bigger size wouldn’t actually achieve the same extraction as the physical interaction between the water and coffee has changed, possibly dramatically. This would also feed into the discussion of possible differences between similar extraction percentages achieved via espresso and filter methods.

A lot of this follows from some brewing experiments we did with sieving for different sizes and then adjusting other brewing parameters to achieve the same extraction, this was hard to mimic. With larger/boulder based extractions we needed to provide application of heat throughout the brewing process as the longer brew times needed to get good extraction from larger pieces would have very different temperatures variation throughout the brew. With fines driven cups, it was difficult to not over extract, the coffee needed to be separated from the water almost immediately. I would say the tests were not anywhere as rigorous or controlled as they could have been. But those drinks fed heavily into this blogs thought process.

Similar extractions at various sizes didn’t taste that similar at all, maybe the fines driven cup needed better filtering, or the sieves resulted in a variation of sizes- an illusion that we had achieved different uniform sizes, when really we’d split the particles up into different bandwidths of unevenness. When sieving, it would be interesting to analyse the results and see how uniform the fines we have sieved off actually are. Would the larger size sieves give more variance amongst boulders or do fines stick to boulders, or are there extra fine fines in the fines sieved dose.
But, all the same it does beg the questions posited above. If different sizes do different things then we may be looking for something different from our grinders. There’s no doubt the EK43 achieves high extractions that taste good. Is this just because the grind distribution is narrower, or is it doing something else as well?

Chris (Mr Hendon whom I worked with on water) has a theory that if the distribution of size in the dose is non uniform the heating will affect the extracted elemental composition of each particle based on size and heat capacitance. That is, there may well be a desirable ratio between fines and boulders that determines optimum extraction.

This may be true. For example the fines cup I made tasted weird, it was both heavy and highly acidic. It didn’t taste typically over extracted. And theoretically it should have achieved a higher extraction that tasted good as the grind was more uniform. The extractions I liked weren’t that high.

The uniformity aspect is very tricky to assess, especially when sieving, For instance, if one were to grind some coffee on the EK for instance and then sieve off the fines, they have eliminated a whole load of one size, thus making the resulting coffee dose of more uniform size, right?

Maybe not

The EK produces a hell of a lot of fines, and when you swap the measurement on the grind assessment graphs form total volume (that is, the total volume that that particle size equates to within the date) to surface area, the fines spike becomes the dominant and strongest part of the graph, in fact the fines represents the biggest amount of uniform and narrowly distributed particles within the overall dose. when you consider that they will also be responsible for the majority of a un sieved extraction things get interesting. The most narrowly distributed part of the dose has been taken away, the resulting dose is now in many ways more unevenly distributed, especially as far as extraction is concerned.

The term “evenly distributed” can itself be full of semantic problems. A narrow bell curve – a lot more of one size could be argued as very un evenly distributed in comparison to a completely flat one that had an even number of each and every particle size, from fines through to boulders. Bit of a word game really. Its fair to say though that in coffee, we mean most of the dose being one size. Even then though, it makes looking at graphs a bit mind bending. You could have a narrower distribution from fines to boulders, but the distribution could be less or more even than a wider one.

This whole topic is a bit mind bending to be honest.

If there is a difference in organic make up from fine to boulder on average then I wasn’t actually even making the same coffee with a uniform fines size at all. I was in fact making a part of that coffee, Id sieved off certain parts of the coffee. This would then make sieving a very different experiment to Mr Walsh’s, as his achieved a uniform grind within the same dose. If I achieved a uniform set of fines from a starting dose compared to sieving, I may get very different results. Maybe.

For arguments sake, let’s say this isn’t happening and that the fines cup is representative of a cup made with uniform size, if this is the case, then something else is happening.

Maybe with no larger bits around, the heat means we quickly extract elements we don’t want from the fines as the heat starts higher and stays higher for the duration of the extraction. Maybe we then want a larger size that takes some of this heat, allowing the top end of the extraction of the fines to take place at a lower temperature. In essence this may mean there is a perfect ratio between two sizes of grind.

The EK definitely produces a lot of two different kinds of sizes. Its overall distribution does appear to be narrower but it produces a lot of fines. (Noted here as approximately 0-80 microns)When the axis on the commonly distributed grind profile assessments is changed from total volume, to surface area contribution, or amount of individual pieces, the graphs then looks very different. It also produces a lot around size 150-400microns.

Is it this relationship that contributes so much to its success, along with a lack of boulders*. The last question I have regarding boulders and fines is to do with extracting from used material, such as pulling a shot through a used puck. Will a boulders surface be more heavily mined for solids by the water? If its un able to get deep in to the boulder will we take different compounds from the surface to reach 20%. As opposed to the fines, where the heat transfer means that we extract different compounds by moving through more “fresh” un mined material to reach the same extraction percentage.

A good friend of mine, won’t like this article, it asks far more questions than it even attempts to answer. I kind of like that. Questions for the sake of it however aren’t always useful, but nagging uncertainties need exploring, and the pursuit to answer them is worthwhile, even if they are dismissed. We are always learning about coffee. I’m excited by the curiosity our industry does and can have, and I look forward to looking back on this at some future point, hopefully benefiting from a new understanding about the mysteries of grinding.

* boulders present an interesting concept as regards espresso flow rate. Logically a finer grind will produce a slower rate and vice versa, the classic analogy being the flow of water through sand, as opposed to the flow of water through pebbles. I guess the question though, is would the odd pebble chucked in with the sand actually slow it down further as the sand almost holds the pebble. The water goes found it and us presented with a smaller space of sand particles to then pass through. Are the pebbles/boulders effectively creating a number of bottle necks within a dose.

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