Tag Archives: Espresso

15g baskets

We have moved over to using 15 gram baskets to brew all of our espresso in store.

I have explored in other posts how our recipes and practices have changed over time. How the value of ristretto style shots became questioned , especially if the goal is the fullest character in the cup. Then how the very definition of espresso has become more malleable and ranging. Longer shots, lungos and the like have gone from being seen as travesties to tentatively and logically considered, to then being fully recognised as positive ways to brew coffee.

Of course, brewing is never in isolation. It is linked to the coffee, grinders, water and roasting. Light roasting can work very well but it is also in danger of not fully developing the coffees character, which is reason in the first place to move away from darker roasting. But baked coffees start to pop up and under developed coffees become very common, both in the flavour form of light grassy sourness or as a brothy vegetal toastiness(where the coffees isn’t developed  but has been roaster darker to compensate).

It can sound obvious, but many roasters I speak too are looking to now roast the coffee as fully as possible before they get the taints associated with pushing it too far – ashy, toasty, heavy. This is a seemingly small but significant conceptual move away from roasting it as light as possible before it is too light. After all, its the roasting process that harnesses the coffees potential and produces flavourful by products. Roasting is a tricky subject and I am excited to explore it in depth ourselves shortly. It’s also great to have more openness about roasting theories within the community, much like the world of brewing has seen, especially as it is all intrinsically linked.

A full even extraction is part of this process of understanding. It’s a complex feedback loop. Roast the coffee to be more soluble and you can achieve shorter shots with higher extractions and vice versa, in that less soluble coffee will need more water to achieve a higher extraction. Seriously underdeveloped roasts will struggle to reach high extractions at all, regardless of the amount of water. Solubility is an interesting indicator of roast and it’s a piece of terminology that is becoming more and more used. Roasting coffees to the same solubility is a concept that I have seen more of. It is also curious to consider how the same solubility could be achieved with different flavour development. But like Extraction numbers in brewing, it has the potential to improve the data and the conversation.

There’s a lot I want to taste in a coffee, I am looking for espresso to have intense complexity accompanied with sweetness whilst also being clean. I also want it to have the body and tactile qualities that set espresso apart (I’m a big fan of lungos, but see them a s different drinks).

In store we have moved to brewing all shots on the EK43. Our preferred recipes often ended between 35 and 45 percent brew ratios. The only downside is that the shots were getting long. Simply put, I didn’t like the way they sat in the espresso cup, they were also often too much. We have In our store always presented espresso as a one size beverage  as opposed to doubles & singles.

Over the years we had dropped down from 20g baskets to 18g baskets. We then thought, hell, why not go even lower?

So we got hold of some 15g vst baskets. The plan was to simply scale down. Keep the same types of ratios and extractions but just have less of the same drink in the cup, effectively reaching a desired portion size.

My initial concern was that it wouldn’t be this simple. The diameter of the dose remains the same, but the depth decreases. This presents questions for both flow and temperature.

Is a shallower bed less or more likely to extract evenly? Also, with a higher percentage of the dose now being immediately accessible to the water, as well as less overall temperature decreasing energy from the dry coffee, will the overall temperature of extraction remain higher?

Our biggest challenges with the drop in basket size have all been to do with restriction in the basket and the ability to get consistently high and even extractions. VST acknowledge the fact that as the basket depth decreases and we use less coffee, the amount of resistance the water faces, changes. The pressure in the basket effectively decreases as the amount of coffee decreases. VST aim to counter this by changing the frequency and size of the exit holes. The goal being to achieve the same resistance basket to basket. Ideally, the same grind should result in the same ratio to coffee to water in the same shot time.

For us it didn’t work. This may be to do with the grind distribution or the roasting styles. With the coffee burrs we just couldn’t get the shot slow enough, and the extractions high enough. We then moved to the Turkish burrs. This did allow us to achieve slow enough flow rates. The extractions went up but they weren’t consistent. The crema was erratic. Finer again didn’t help matters. We were hitting a celling on extraction and it would appear that by going so fine we were actually lowering the extraction, with the bed creating pockets of clumped fines that hindered the flow of the water, in essence having a coffee puck full of channels. This was something I had heard of before but had not encountered so obviously.

Next we took the dose up to 16-17g to increase resistance/pressure so that we could grind a bit coarser and hopefully achieve more even extractions. We collapsed heavily to keep head space, evenly distribute the bed and worked a nutating tamp in to the mix. Results improved. We also dropped the temperature from 95 to 93 to compensate for the potential increase of overall brewing temp and this also slowed the flow down again. This was all with the Turkish burrs. I still preferred the results I could achieve with the coffee burrs in bigger baskets.

The real success came by taking the pressure down to 6 bar. I was thrilled to have someone suggest this to me. On the San Remo Opera this gives us a flow rate of 190g of water in 30 seconds (straight out of the group with no handle inserted). If the pressure and flow are relative to restriction then it makes sense to lower pressure as restriction is lowered.  This has allowed for use of the coffee burrs again. The results in the cup are top notch.

The exploration of this basket size, was as you can see not without its problems, but the successes are multiple – espresso beverages of our desired serving volumes, with full, even and flavoursome extractions, that saves us coffee and money. Happy days.

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A Narrowing Gap

This is mostly a follow-up on a post I wrote around a year ago which explored the idea of set recipes and dialling in, specifically regarding espresso. As well as bearing that post in mind, here I’d like to explore espresso and how I feel about it at this moment in time.

A lot has happened during the past year -such is the current pace of exploration in speciality coffee- and our evolving relationship with it, particularly where espresso is concerned. An Australian barista champion joined forces with an American coffee professional and together they delivered a WBC performance and resulting events that, when you step back and think about it, have had a rather huge impact in the speciality sphere. And not just by creating an 18 week waiting list on a particular grinder. Just over a year ago I would not have contemplated brewing a lungo style shot at all. It definitely wasn’t being considered as part of our menu.

Zeitgeists in coffee have an impact which is sometimes hard to quantify, but we definitely see changes. As a multi-roaster store we are not just deciding how we would like to brew coffee, but are choosing how we would like to brew other peoples’ coffee- those people who have roasted it.

The way in which we prepare and taste coffee impacts on what we will have a preference for and what we will work towards, as well as what we will work backwards from. We have to start somewhere. My post a year ago was wrestling with the idea of not exploring variables and trying to set them still. But at the same time we all have a window for brewing coffee, some narrower than others. The danger being that if we don’t have a big enough view then we may miss some of the landscape. But at the same time if it’s too large we may not be able to focus on the details and improve things.

For us at Colonna and Small’s, this window has gotten smaller and in a good way.

Our preferences have most likely changed a little bit, but I think that other things have changed as well. We have embarked on a project which has left us with a better understanding of brewing water and this information dramatically informs the brewing process. We hope to publish this research in the form of a book shortly, but we have also decided more precisely what we want from the coffees we buy and therefore the suppliers whose approach we jive with. This has meant we don’t buy coffee in the same way we did before.

Before we may have been willing to tussle with a coffee to get the best out of it, but now we are more informed about what we may struggle with, say a coffee from a roaster that has significantly different water sources or brewing practices. So I would say we are looking for the same kind of flavour results but narrowing the net we cast within which to find them. This also naturally means we are setting an end point of sorts to work towards.

For a long time the speciality coffee industry has been moving away from the double ristretto style in acknowledgement that it is almost impossible to squeeze the character of the coffee into such a small amount of liquid, in that the extraction will nearly always be low.

A ristretto is easy to write off but the range within the espresso cannon is wider and more varied.

Throughout the last couple of years the focus on extraction and TDS* and their relationship has impacted how we see espresso. The exploration of lower TDS espresso-style beverages has most likely also stretched and challenged the idea of what an espresso even is. For me there are limits on this and I feel that below a certain TDS it just doesn’t taste like espresso. Hence the Lungo we sell. With the right grinder, the right style of roast, brewed at a lower pressure and with a quicker brew time (to make sure we don’t exceed an extraction we feel tastes good) it tastes great, displaying the character of the coffee, but it’s not an espresso to me.

Drinkers in our shop have often really enjoyed the lungo, with it not being as delicate and nuanced as the filters nor as intense as the espresso. However, those wanting or with a real attachment to espresso haven’t enjoyed them so much. It has been important for us in store to bill the lungo as a different way of displaying a coffee rather than as a lower TDS espresso.

What’s particularly significant for both the variables of brewing styles/goals and that of water, is that they both will impact on how the coffee is roasted. A couple of the roasters we work with will roast specifically for us, in one’s case it’s to explore lighter roasts that don’t necessarily suit all of his customers needs. For the other, it’s to explore coffee together for competition and for water spec.
Regarding this latter roaster, together we will cup coffees that are currently available or are coming into the country from a variety of importers. We will then choose the coffees we wish to buy and the roaster will roast a variety of profiles, normally this is three distinct and different profiles to guage the direction in which we want to go with the coffee. I will brew these coffees and the process will continue in a feedback loop in which we both take part. So, in short, how I decide to test the coffee combined with the water and the grinder will all enter the feedback loop and massively impact on where we end up.

In essence we are working back from a brewing point. This notion is one that I in some ways rebuked in the set recipe post last year. At the same time it is something we are in many ways now doing by cutting out roasters whose results may not correlate with our water as well as tailoring coffees to TDS and extraction numbers -although we are still marginally flexible on this.
We are all doing this in some way. Roasters, for example, will find a set recipe style they like to work with and their coffee will be influenced by this. This kind of controlled environment makes a set recipe, or a “work backwards from brew” approach, a more linear and predictable path as the testing environment is more controlled.

At the same time, roasts vary, and water varies, even with careful supervision. And small variances in recipe are still something we use. We do this because our main goal is to serve someone the best coffee at that moment in time. We may be able to trace a negative aspect of a coffee’s taste back to the roast or a change in water, but I don’t want to use that as an excuse for the customer I’m preparing the drink for. Of course, tweaking recipes and parameters cannot hide massive flaws in the system, and on these instances the coffee may have to be removed from the menu altogether. But a better understanding of what our suppliers may be aiming for and understanding the nature of their feedback loop as well as our own has meant that the variance in the recipes we use has narrowed. It also follows from this that we are naturally, through such processes, pushing towards more singular recipes.

But is there an event horizon for coffee brewing or are we making one? Of course, this event horizon is most likely to be defined by TDS and Extraction combined. After all, variables need to be set to judge anything, but it’s also coffee’s complexity that often makes a lot of our created judging systems flawed either way, whether we set the variables or change them.

Currently our recipes in store tend between 40 and 55 percent brew ratio mark (twice as much shot weight as dry dose weight) with TDS around 9-10 percent and extractions between 19 and 20 percent and on occasion up to 22 percent (these numbers are not with the EK43, but with a K30). Sometimes though this is more the coffee than anything else. At the moment a light roast pacamara manages a much higher extraction under familiar circumstances as slightly heavier roasts of very different origin coffee, which is unusual as lighter roasts tend to be harder to extract from. The question is though,could we go back and roast the pacamara coffee in a way that means it tastes better at 20 percent rather than 22? really we’d prefer to get the others tasting good at 22percent. Or are we struggling against the very nature of this unique product. Can we have a singular recipe for all coffee? Maybe here we need to have our  rules and allow for anomolies.

And this is where the constant cycle of dilemmas between the concepts of brewing theory and flavour in coffee keeps leading me, to the space between set recipe and variability.

Let’s see what happens in the next year.

 
* TDS denotes the concentration of coffee in the coffee beverage, rather than the amount of coffee extracted into the liquid, for example a ristretto is highly concentrated but its hard to get a high proportion of the coffee into the liquid. Where as 1 gram of coffee to a litre of water would be an extremely weak coffee to water ratio, but it would be much easier for the water to extract a lot form the coffee as it doesn’t have much to deal with.

I find it useful to discuss it as workload. More coffee means a higher workload for the water. It has got more work to do to get the coffee into the water, and in some cases will simple not have the capacity (ristretto) and hence the extraction is likely to be lower even though the strength of the beverage is higher. less coffee results in a lower workload for the water and therefore it can achieve a higher output(extraction). We can help the water out with things like grind and time but there are limits on the work it can do.

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