Coffee is full of surprises.

In our minds eye we categorise everything, putting labels on ideas and experiences. What do we label as good and what do we label as bad?

Speciality coffee is an area of the market place that often has a mild tension between exploring the new, exciting and innovative whilst also searching for a more constant, authentic idea of quality. The two are not always mutually exclusive, that’s for sure.

We experience technology. In coffee that means we experience a drink that a certain piece of technology played a part in creating.

The drink essentially defines our idea of that technology’s value, of its capabilities. The technology however is not the sole maker of that quality. It has a user, a driver. A product it was asked to prepare. It is often extremely hard in coffee to separate which element of the making process is responsible for which flavour element. The water project has displayed this starkly.

Have a bad batch brew, brewed with undesirable beans and little governance of the process and we could possibly deduce batch brews are then bad. Somebody lovingly makes us a pour over with great coffee and then we may deduce a pour over is far superior. Case closed.

It is also true of course that meaning is placed in the making process itself. There is a value system here and not one to be shirked off. Ritual and process have their place.

However it is often stated that something objectively makes good or bad coffee. This is the concept being explored here.

Capsule systems are particularly unique in this regard as the product chosen to be delivered via a capsule system is more curated. Your choices are limited. It requires a fair amount of expensive technology to put coffee in capsules, especially if you really play with the technology.

Capsules currently available on the market place do exactly what they’re supposed to do and they do it very well. It’s just difficult to realise that if we don’t share the same product goals. They are supposed to offer an espresso style drink with loads of crema, to an audience looking for and expecting a traditional commercial coffee taste profile.

I’ve always been interested in tasting what the rest of the coffee world beyond speciality has to offer, not because I personally enjoy it, (although I appreciate others do) but because of the reference it offers. I find it interesting to see what people are drinking and how the flavour relates to the narrative the companies are telling.

A few years ago, a friend of mine who works for a very successful company in the traditional Italian style market was kindly driving me from London back to Bath. He pulled over into a layby excited to show me something. The company’s latest in car capsule machine was revealed.

This is a big company whose whole bean and ground coffee I was very familiar with and had tasted on a number of occasions. I thought it was all very neat that we were brewing espresso on the side of a dual carriageway half way through our trip, but what really caught me was that it tasted better than any other experience I had had with the companies coffee. For me this was the first time I had been able to experience a direct reference, to see what Capsule delivery systems are capable of brewing wise. In the past I had always tasted coffee from a “capsule only company”, so I didn’t know what that coffee tasted like when brewed manually.

The idea of using capsules as a genuinely worthwhile way of brewing speciality coffee is likely a rarely held notion. The zeitgeist and status quo of the community does warp and evolve regularly though, and what was not considered at all a few years ago can suddenly become cautiously considered and then embraced.

So, is now the time that capsules go from being ignored, even hated, to embraced by the speciality coffee community.  A valuable and unique delivery system for the coffee we are looking to share?

Personally I like to try and remain open minded to any delivery system.  That is if it is able to combine water and coffee in a way that the resulting beverage displays the characteristics that define the coffees provenance and value.

I really think capsules are a unique and valuable delivery system with many additional benefits.

Over the years we offered coffee training courses in our store. These courses were often bought by the non industry drinker. Friends and family would buy a course for their coffee obsessive hard to buy for sister or friend.

Personally the courses ended up being extremely fascinating for myself. There tended to be a correlation that individuals from very interesting fields of work would come on the courses.

At the beginning of the course I like to get to know a bit about my student. We quickly cover their interest in coffee and how they currently approach preparing themselves a cup. More often than not we discuss how they have an Aeropress and buy coffee from such and such, and use scales etc. Then comes an apology.

“I’m sorry but for the office and for espresso type drinks I have a Nespresso machine. I am not overly enamoured with the results but there is a lot about it I like. Ease of use etc”

In consultancy jobs I would often come across discussions about capsule systems. In this case it was more a frustration about a solution for their business that offered them the convenience and the quality/flavour profiles they were looking for. I remember a restaurant owner that told me how they had tried capsule solutions but weren’t happy with the results, so they moved over to a manual set up. Lots of investment, staff training and quality control. However, if they were honest with themselves the quality was incredibly hard to maintain across the staff base. At the low points the consistency and quality actually dropped below that of the capsule. So now they are back with capsules. Their question to me was, do I have a solution?

I think the wrong way to see capsules is that they are in danger of replacing the craft and quality of a handmade espresso. The right way to see them is as just another brewing method. “Just” sells them a bit short though.

It is a brewing method that many people are using. The exciting thing here is the opportunity to display amazing coffee in another way.

The shift of narrative that comes with a more “finished” product and single servings is also something to get excited about.

A customer buys a bag of beans in my store. The discussion we have has a strong likelihood that it will focus on brewing methods and guidance mixed with the provenance and flavour profile of the coffee. We may chat about grind, water temperature, weight of coffee to water etc. For a lot of customers this adds to the immersion of the experience and there is a lot of value here. But the idea of also offering coffee in a way where we skip the making lessons and focus on the choice of coffee as the centre of the experience is alluring.

The dynamic of the experience with the coffee can then manage different angles in one fell swoop. The dialogue and story are now primarily about the coffee itself and what it can offer in the cup.

Choice and comparison become the central experience. To taste different coffee and origins in the speciality sector at the moment you would have to buy several bags at once, which when opened present staling issues and then you have to brew two or three manually side by side to try and taste multiple coffees. You have to grind them individually and so on and so forth.

Today I was sat in a café in London and we plugged in a capsule unit (with the permission of the proprietor) and tasted different coffees side by side within a minute or two, then discussed the flavour and origin of each.

This didn’t dumb down the experience. It had its own value. Just like the several stages of a more crafted traditional process have their own value. I brought my own water in a bottle to get the best results. We effectively focused on ingredients first and foremost.

The capsules we were drinking were ours. It was so exciting to see them fit in neatly on a table of well-prepared speciality coffee drinks and brewing methods. In fact they won some favour in places.

Of course, you, the reader have likely not tasted them. Currently, this is all hypothetical for many.

Hopefully, early next year you will be able to make up your own mind……..

Leave a comment

Filed under Uncategorized

Catch up

I have been pretty busy, in the most positive of ways. There is so much potential for collaboration, exploration and rewarding experiences in coffee.

It’s been a while since I wrote here, so I thought I would do a little summary of the projects I am involved in, a bit about each and the hope of expanding on each in the near future. I have always loved the medium of a blog to get ideas and thoughts down on paper.


Water for Coffee

Several weeks ago, myself and Christopher H Hendon released our self-published book on the topic of water for coffee brewing. This was the culmination of research over the past couple of years. The book has sold really well and the coffee community definitely appear to be enthralled and interested in this amazing topic.

One of the most positive aspects of being able to create a book like this and get it out around the world, is how the dialogue and discussion suddenly widens. There will always be more we can learn with a topic like this, as it is with much in coffee.

An immediate and fundamental point to consider, which has been gained from the input of readers is that of standard water measurement. We are interested in the individual aspects of the water’s mineral composition and how the role they play in the extraction and flavour organising process. However, it has become abundantly clear that the standard unit with which to communicate hardness in water is Calcium Carbonate (CaC03). This basically means that if a specification is written with CaC03 as its reference you then have to figure out a conversion to get your actual amount of calcium for instance.

We have explored this concept in a written corrigendum (an error to be corrected, esp. an error in print). This is available here and is supposed to accompany the original volume. Research into this topic continues, by ourselves and by others. This is an evolving project and we intend to release a volume two next year with additional content.

The particular point to take from this is that it is very important to know that these two ways of expressing mineral content exist. This is specifically important when interpreting a specification and when understanding the result from a measurement device that may measure in either expression.

For example take two interpretations of the SCAA water metric.  The larger box interprets the numbers presented by the SCAA as straight ion whereas the other box denotes the same numbers when considered as CaC03, therefore resulting in a lower actual ion reading.

scaa water

More research

Coffee is full of hidden details that can be better understood and explored though scientific practice. A personal fascination of mine is coffee grinding. I have written about this at length before, here and here.

There is doubtless much research to be done with grinding, as it seems that when one question develops an answer, then several more questions arise, with the potential of several more tests to be done. Like the Water book, research here has greatly benefited from collaboration.

I feel there are several aspects to grinding coffee. There is the distribution of particle size, from the very small to the not so small and what this means for extraction. It’s very hard to test a single variable however, as by grinding coffee differently (by changing the grind) we may be effecting heat transfer during extraction or flow rate during espresso brewing. There is then the issue of dosing and distribution.

One of the topics that was explored in a previous blog here and has been expanded on by others is the impact that the temperature of the bean has on the particle distribution of the ground coffee when the burr setting remains constant. This presents a good test as the variables are controllable and the answer we are looking for can be relatively easily measured. Well, you need a laser particle analyser, which Chris managed to wrangle for a day’s use in our shop.

Myself, Chris, Matt Perger, Cristian Klatt from Mahlkonig and others, are currently finalising a paper to be submitted for review and hopeful publication on the effects of heating on particle distribution. The paper will include some other interesting and surprising findings.

One of the revelatory perspectives I have found and like to present, is the 3 various ways that a particle analyser can display the same information. Below is an image of one set of data interpreted to represent volume percentage, surface area contribution and number count.

partivle dist

I find this a tremendous display of how the question asked can completely change the answer based on the same topic, in this case data on ground coffee. Volume % denotes how much of the overall volume of the ground coffee is taken up by that particular size of ground. A boulder or larger particle will take up a lot of volume and present itself as prominent on a graph that interprets only volume. Smaller particles will take up a fraction of the space and will appear less important in this interpretation. When the data is adjusted for contribution to surface area, everything changes and the smaller pieces become far more influential and start to dominate the interpretation. They may take up less space but they contribute a lot to surface area. Lastly we have number count. This changes everything again. In this espresso grind the particles under 100 microns contribute to roughly 20% (this number is derived only from this data and one grinder model) of the volume but this twenty percent is made up of a hell of a lot of those small pieces. When we change the data interpretation for number count the data suggests there are almost no pieces over hundred microns. Fascinating stuff!


Colonna – Sourcing and roasting

We have started a roastery, well just about. We have a premises, some rather special green coffee and various equipment making its way through customs. We are tremendously excited by this project. I could explain the concepts behind the project here, but an interview by Sam Maccuaig for Sprudge does a great job. You can find it here.

A lot more on this venture coming soon.



Sanremo are an interesting company, one undergoing a massive change of direction. This started with a collaboration with John Gordon a few years back and resulted in the Opera espresso Machine. This machine will be presented in its final updated V2 form at Host in Milan in a few weeks. It will be accompanied by other new projects that Sanremo have been exploring. This year I was asked to become part of an international development team. Together we are working on new equipment aimed at the cutting edge of what’s possible.

I joined this project not only because it provides an opportunity to get behind the scenes, to learn more about, and be involved in the technology that we utilise to make delicious coffee, but also because the company proved to me to have a flexibility to become inspired by a concept or a goal and to approach it creatively and to make it happen. The international group I’m working with is of an amazing quality and it’s very exciting to see where we can go together.

If you are at Host I hope to see you there and to serve you some Colonna coffee; that is if a certain roaster makes it through customs in time.


WBC development board

I guess you could say I am currently retired from competition. Never say never, but I won’t be competing for at least 3 years. I took the opportunity to become involved in the WBC development committee which is currently exploring how we can evolve and develop the World Barista Championship. Being so heavily invested and involved as a competitor, it is fascinating and rewarding for me to get behind the scenes. The coffee competitions have played a huge role in the speciality coffee community and I am sure they will continue to do so.

It’s intriguing to assess something that is already very successful and to look at where it can go. It is easy to criticise something like the WBC, I myself have been a critic of certain aspects during my competitive career. I do think the competition can improve, but it’s also important to be aware of what works, of what makes it special and to maintain that whilst addressing the elements that can improve.

Unfortunately (but also naturally and sensibly) I can’t divulge the details of this process. You’ll just have to wait and see what changes in the coming years.


National Coordinator SCAEUK

Speaking of competitions, I have taken on the role of National Coordinator of the UK chapter of the SCAE.

Much like the WBC board, getting involved in the running of the UK chapter really appealed to me. I am working with a great board over the next couple of years. Our goal is simple really. To take the potential and support for these competitions and to maximise and explore it, creating as much value as possible for all of those involved.

There is a lot of support for the chapter and that has a huge impact on what we are able to do. In summary we are looking to expand the nature of each event, hosting the competitions and the heats at venues that reflect the speciality coffee community. We are looking to further the success of the UK Barista championships but to also make the most of the increasing popularity and potential of the other competitions.

For updates and info keep an eye on the chapter’s website here.

That’s all for now.

Leave a comment

Filed under Uncategorized

What’s Your Real Dose?

Chatting away with Jonathan at Repack espresso(conveniently located near my house) this morning was the beginning of this blog. I thought the conversation provided a neat narrative for considering the impact evenness and extraction can have on how we percieve brew ratios.

We chatted about the conceptual differences between an EK coffee burr espresso recipe and other grinders, in this case, his Anfim grinders.

What is your real dose and for that matter real extraction?

Let’s say that we both start with a 16g dose and dial a coffee in to achieve a desired extraction and strength.. Jonathan dials in a single origin coffee in his store (a roaster and coffee we also use in our store). I however dial this coffee in at our store and use an EK with coffee burrs. My recipe that achieves a flavour of both strength and extraction that I am happy with is predictably a longer shot – 16g in to 39 out. This tends to be common practice for an EK. Most of our shots are around this mark. Jonathan’s is predictably shorter – 16g in to 34g out.

There’s a touch of dryness on Jonathan’s shot but its really good. After chatting about our recipes he tries a longer shot but as is often reported it was thin and over extracted tasting.

It’s easy to think we are using the same dose in and exploring the same yields out. But we are not.

The difference is all about evenness. Conceptually its easy to recognise that a more even grind means we allow the water to access more of the coffee at once. This then means that the we can hit a higher extraction without the over extraction taints we have correlated with certain refractometer numbers. For example EK shots often taste under extracted at 20 percent, whereas as similar under extracted taste is achieved at a 17 percent reading on another grinder. This isn’t exclusive to grinders though. The physics of even extraction that can be improved with lower flow rates/pressure (as explored in the previous two posts) present a similar phenomenon. Extractions that peak at a higher number when the brew is tasting its best compared to before.

In both cases we are extracting more evenly, and nowhere is evenness more impactful than when brewing espresso.

As these change, so does the use of reference points, such as brew ratio and extraction.

So, back to the title, In both cases – lower extractions that taste balanced and higher extractions that taste balanced- are the doses of coffee we are starting with actually the same? Well, as a dry weight on the scales, Yes. But, as far as the water is concerned, No.

If the grind is less even or we are extracting from less of it from some reason, then we are not actually using 16 grams, maybe we are only using 14g. I don’t know for sure, but for arguments sake, let’s assume it’s 14. From a grinding point of view , if we get a load of boulders, as we may from a Robur, then that “coffee material” is not fully accessible to the water. Part of the 16 grams is tied up in the bolder, essentially taking down the dose you are actually brewing with. The same goes for the physics of brewing, lets say the water passes through the coffee less evenly, either because of distribution, flow rate or evenness of grind. The water will be using less or more of the dose, effectively completely altering the brew ratio which we so often discuss.

This then impacts hugely on the refractometer reading, especially when converted to represent extraction.

When we type in the TDS% reading to the mojo app, we also type in our starting dose and shot weight. The calculation that takes place considers that we were extracting from the whole dose, in this case 16 grams. What if using a less even grind actually meant we only really used a dose of 14 grams? If we then type this as our starting dose into the mojo we would get a much higher extraction reading.

So in essence, are EK shots really that much of a weaker ratio than other espresso shots? For example the two recipes myself and Jonathan decided upon when using different equipment seem very different on paper, but in reality they may be much closer than they first appear.


Filed under Uncategorized

Pressure & Flow Restriction

It was terrific that the last post was so well received. It would seem that from others’ experiences and some more of my own that a lower pressure/flow has the potential to improve extractions irrespective of the grinder. The suggestion being that lighter roast coffees are harder to extract from evenly as a pressurised pour over (aka espresso) and that a lower flow rate helps with this.

The dialogue on the topic of pressure has mostly suffered and been stifled by the conceptual differentiation of flow rate and pressure. I was motivated by this misconception and wanted to explore the language and theory in this post.

We can start by stating that flow rate applies only to water and pressure refers to only the pump. In an espresso machine, the pressure determines the flow rate of water, but this pressure is not the hydrostatic pressure of water.  The pressure in an espresso machine refers specifically to pump pressure: whatever technology the pump is based on. Flow rate and pressure are not the same thing when dealing with gases, but all we care about when talking about coffee extraction is the rate at which water is pushed through the coffee bed.  Before we can explore the physics, we must go on the journey water takes through the machine.

When we make an espresso, water is forced towards the group using some sort of pump.  This force comes from applying pressure to the water.  But this does not mean that the water is pressurised.  Where did the word ‘pressure’ come from in terms of espresso machines?  Pressure is an important measureable for gases and most espresso machines force water through the pipes using some form of pump.  This is very different to applying ‘pressure’ to water.

Now that the water is moving, it progresses through the group, followed by exiting the shower screen.  It then comes into contact with a resistant barrier (the packed coffee dose).  Instead of permeating through the coffee, water is continually pumped into an open head space above the coffee. Once all of this space has been used up and there is nowhere else to go the water is forced through the coffee.

The coffee and the holes in the basket are effectively the exit point for the water. They’re simply resistors, so the flow rate is defined simply by the rate in which the coffee travels through these resistors.  We use liquid water to make coffee, which makes the discussion of pressure somewhat easier. Unlike something like air that will readily compress significantly under pressure, water is almost completely uncompressible. For example, at 4km beneath the ocean’s surface water only compresses by 1.8% by volume. Hydraulic cranes work by filling metal sleeves with water that will not compress even when lifting very heavy objects.  We know that water expands when temperatures deviate from 4 ºC, but, in terms of an espresso machine, the density of water is only a function of temperature, not pressure, and this means that we can measure the flow rate in L/min.  Any object in the way of the flow of this water will slow its rate.

It gets tricky here, because in an open system (where the water can leave by for instance flowing out of the basket) means we must consider displacement. The water entering the basket displaces the water already occupying the basket. Given that the basket (including coffee) is the resistor; the rate of displacement defines the “pressure” in the basket. Note that this effective pressure is simply measured by flow rate, and hence if the pump pressure decreases the flow rate does too.  Not because the water itself is less pressurised, but because the force pushing the water is less.  When we increase pump pressure we increase the flow rate of water exiting the shower screen and vice versa for a lower pump pressure.

There is another way to lower the flow rate coming out of the group head called a flow restrictor.  A flow restrictor is basically a little pipe that the water passes through during its path to meet the coffee. It effectively funnels water into a narrower pipe, and like traffic on a motorway getting pushed into one lane, the same volume of traffic will now take longer to pass the same distance effectively slowing the traffic rate.

If we consider a machine that has a pump achieving 9 bar pressure pumping water through the group. We then install a narrower flow restrictor in the path. This slows the flow of water down at the point of the flow restrictor, which directly decreases the flow immediately after the flow restrictor.  Our  pump pressure remains high,  but the rate at which the coffee brews goes down.  We have effectively lowered the flow rate using a flow restrictor rather than just lowering the pump. There are mechanical issues to consider but in essence the flow restriction and pump pressure impact flow rate the same way through different modes.

It’s much easier to just adjust the pump rather than exchange a flow restrictor.

To help illustrate this problem, below is an image that show that as the flow restrictor becomes narrower, there is a greater difference between incident flow rate (i.e. incoming pump pressure) and exit flow rate (i.e. the flow of water after all resistors have acted on the water).  Furthermore, you can achieve exactly the same effective flow rate with any flow restrictor, Simply by adjusting the pump pressure to compensate for the flow restriction.

This first image displays how different in going flow rates create different out going flow rates with different flow restrictors


This second image displays how flow rate going in can be altered to achieve the same outgoing flow rate when the flow restrictors are different.


It would appear that discussing pressure and flow restrictors over complicates the discussion. In terms of sharing brewing parameters it makes more sense to describe the amount of water that exits the group in a given time with no resistance. This way we implicitly understand the relationship between pump and flow restriction on a given machine.  It also removes the obvious variable of grind size, which directly determines how strong a resistor the coffee bed is.

Leave a comment

Filed under Uncategorized