Espresso Recipe Building & Calibration
How we build our espresso recipe at Common Space Coffee
We do free coffee appreciation class twice a month. One of the common beverage/ingredients we present and serve to our customers is espresso. And we have a hard time explaining that. The definition is simple, a very concentrated coffee made using espresso machine with hot water and high pressure. You can read more about it here.
But it took us quite some time to dive deep and explain about the recipe of espresso to non-barista. So, just to let you know in advance, this article is for the serious coffee lover or barista. If you’re not, you might find it boring or to better describe, confusing. We’re going to show you how us, Common Space build our espresso recipe and how we calibrate it.
Building Espresso Recipe from Ground Up
First of all, we have to forget what we had learned. Before I found Common Space, I was a barista at chain cafe long before third wave coffee was introduced in Malaysia. During that period of time, the definition of espresso is a 30ml concentrated coffee extracted using 7g to 10g of coffee ground in 30 seconds.
You see, the recipe here is fixed. We don’t have much room to play around and experimenting here. If you get a delicious espresso in 45 seconds. You are wrong! It has to be 30 seconds. And I was that barista who obsess about 30ml in volume and 30 seconds in extraction time.
At Common Space, we build our espresso recipe according to the taste profile we like to get from the beans, which mean we prepare every different beans a little differently, but with a few key principles, parameters and process.
Of course, there are too many variables that will affect the results in your cup. Therefore, we still need to fix and lock in a few variables in the recipe. Here is how we do it.
Step 1: Lock In Your Dosage & Identify The Brewing Ratio
First thing first, we lock in our dosage, which mean the amount of coffee ground we use in a portion of espresso. We are using a scale to measure in the unit of gram. There are 2 reasons why locking in the dosage should be the first step.
First, we don’t up-dose (fill in 22 grams of ground coffee in 18 grams porta-basket) or down-dose, this will ensure you have the optimum pressure and enough room for extraction in the group head during the brew.
Second, the dosage is going to affect the cost directly, lock in your dosage so you know how much you are going to spend for an espresso. We’re using 18 grams of coffee ground at Common Space.
Then we identify the volume of the resulting espresso we like to get. Note that we are not limit our volume at 30ml. The higher your brewing ratio (coffee to water), the more dilute your espresso will be. This will directly affect your brewing time and level of extraction too.
This is something I never look at few years back as a barista. We don’t even use the same measurement unit for coffee ground (gram) and espresso (ml) back then. Therefore, we’re using the measurement in the unit of gram too to improve the accuracy of brewing ratio. We’re using 1:2–2.5 brewing ratio for our espresso here to get the buttery mouthfeel and optimum texture.
We don’t actually fix our brewing ratio at the first place when we’re using a new blend or single origin for our espresso. We will carry out a few tests from 1:2 all the way up to 1:3 brewing ratio to get the optimal body that we like.
**If you heard about Ristretto before, it’s a recipe where the brewing ratio is at around 1:1 to 1:1.5, which mean you get 20g — 30g of espresso out of 20g of coffee ground. The reason why Common Space never use this anymore is because the strength is too high, it does create high in flavor (but not complete) and very sharp in acidity at the same time. Besides, we realized that this recipe lead to under-extracted espresso due to short extraction time and create wastage that cause a loss in both customers and the coffee shop.
Watch this 3 minutes video by Matt Perger, it explained a lot why we don’t do Ristretto anymore.
Step 2: Experimenting Extraction Time With Grind Size
Up next, we will then experiment our extraction time. We don’t use the traditional 30 seconds rule here too. We will run through a series of experiments from 25 seconds all the way up to 40 seconds (even to 60 seconds if necessary).
As you can see, we have fixed the dosage and brewing ratio here, in order to get different brewing time. We are adjusting the grind size to fine tune the extraction.
From there, we do a lot of tasting for each espresso we got. What we like to get here is not just sharp acidity, but balanced cup with sweetness (believe me, we can taste it when you get it right) and optimal buttery texture for your cup of espresso.
Sometimes it might take a little longer to fully extract the espresso. That’s why removing the “30 seconds imagination rules” is important and critical in this part of the process.
Finally, lock in your extraction time and you will have your recipe with dosage, brewing ratio (the final volume of resulting espresso), and extraction time. This should leave you a pretty good control for the espresso. Now, the only variable we can’t control is the freshness of the coffee beans, that’s why we need calibration.
Calibration and Taste Your Espresso
Here come putting this into daily practice and calibration. Once you have your espresso recipe, you can calibrate your espresso every morning before you serve your customers, friends or yourself. Lock in your dosage and brewing ratio, record the total extraction time to achieve the resulting weight of espresso you like. Then adjust the grind size to get the brewing time in your recipe.
If you are a barista, you should notice it’s much much easier for your to calibrate your espresso with very few trails, that directly reduce the wastage and improve the consistency. Because we had locked in all the key variables, and leave only grind size as the control variable.
If it takes too long (longer than the preset extraction time) to complete the extraction, which mean the grind is too fine and you need to turn it to coarser, while if the extraction is too fast (shorter than the preset extraction time), adjust the grind finer so you can achieve the desired extraction time.
We know most people don’t just have espresso the way it is, but when you are building your recipe and calibrating your espresso, make sure you taste the espresso but not just the cappuccino. You might get a bad espresso but balance cappuccino, which mean your espresso still bad.
But if you get the espresso right, we are pretty sure your milk coffee will not go wrong unless you are using too much milk for a shot of espresso there.
Tips For Better Extraction
We had covered the recipe in a very mathematical approach. But there is one tips that can dramatically improve your espresso to get even more balanced, flavorful with optimum body & mouthfeel. Which is distribute your coffee ground evenly before tamping, and tamp flat with consistent amount of force. We will write more about the technique in detail in coming article.