Espresso has always had a mystical aura around it and for someone new to coffee this can be a daunting thing. Whether you’re a home barista or new behind the espresso bar, dialing in espresso doesn’t need to be so scary.
Together we will explore the parameters that affect espresso extraction and break down all the barriers to demystify dialing in espresso.
This how-to on dialing in espresso will go through the fundamental steps required to dial in any espresso using only our taste buds as our guide.
By the end of this comprehensive guide, you will learn a very powerful system of dialing in espresso that will help you get a much better understanding of coffee.
Welcome to the ultimate guide to dialing in espresso for newbies, are you ready?
The espresso recipe
Every espresso recipe should start off life on a piece of paper written up as a recipe; extracted, tasted, and constantly refined.
Regardless of brewing style, the goal of brewing coffee is the same; to dissolve just the right amount soluble flavour and aromatic compounds into our brewing water at just the right strength to make it delicious.
To control the rate of extraction and the final strength of our espresso, we must consider three basic parameters in our espresso recipe; dose, yield and time.
These three parameters on their own have a huge impact on our extraction. To get the most delicious espresso, we must fully understand and control them to get the best possible outcome from the beans we have in our grinder.
Every coffee will have its own recipe or set of numbers that will make it taste good. This is due in part to provenance (origin), climate, variety, processing method, roast degree, and equipment.
For example, the perfect recipe for one Kenyan SL-28 coffee might not necessarily translate well to a different SL-28 variety coffee from the same region in Kenya.
Let’s break down the recipe into its components.
The dose or dosage refers to how much ground coffee is being used in our brewing system.
In the case of espresso, we must first decide on which portafilter we want to use; either the single or double spouted portafilter. Sitting inside the portafilter is a filter basket held in place with a spring.
How much ground coffee your basket holds depends largely on its diameter and depth. I’ve written a quick 3 step guide on how to size your filter basket in another post. So if you don’t already know your basket size, make sure you read the guide before continuing.
Once you have sized your filter basket, for the purposes of this guide, it is advisable to dose exactly that amount of coffee in. For example, if you have a 14-gram basket, you should dose 14 grams of ground coffee into it. If you have a 22-gram basket, dose 22 grams of ground coffee etc.
If it isn’t already obvious, we’re going to need a good digital scale. At The Espresso School we use the Brewista Smart Scale II to measure both doses and yields. This scale has a resolution and accuracy of 0.1 gram up to 2,000 grams.
In this example, we will be using a 20-gram straight walled double filter basket, so we will be dosing in 20 grams of ground coffee.
After dosing, evenly distribute the ground coffee in the portafilter to prepare it for a flat and firm tamp. We are now ready for brewing.
The yield refers to the total liquid output of espresso from the machine.
The yield has two properties we can measure, namely volume and mass. The preferred property is weighing the espresso mass (a.k.a yield) for ease of measurement and consistency.
The Brew Ratio is a concept that defines the relationship between the dose and the yield. For regular espresso, this ratio is ideally at or close to 1:2. A 1:2 ratio means for every gram of coffee in your basket, double it for your liquid espresso yield out.
For example, a 20-gram dose at 1:2 would yield a 40-gram double espresso. 18 grams in, 36 grams out. 25 grams in, 50 grams out. You get the idea!
At a ratio of 1:1 you’re in ristretto territory, thick, heavy and strong. At 1:3 you’re in lungo land, thin, delicate and weak.
We recommend a starting at a brew ratio of 1:2. In our example, the target dose of 20 grams in means our target yield should be 40 grams out.
To achieve this, we will need to extract the espresso on scales until the target yield has been reached. So whip out those trusty scales again because it is now time to brew.
What you will have noticed is that if you cut off the shot when the scale reads 40 grams, the drips of espresso at the end of your shot will contribute to your final yield causing you to overshoot the target.
You must offset this by cutting your extraction off earlier by exactly this amount of overshoot.
The drip offset is usually somewhere between 4-5 grams depending on your machine, coffee and grinder setup. Cutting off the extraction at 36 grams will allow the drips to bring the final yield up to our target of 40 grams.
Time is the final piece of the puzzle in our recipe and can be thought of as two ways:
- how long did it take for the target yield to enter my cup
- how long did the coffee grinds stay in contact with the water for
Time is a driver for extraction. It’s very simple and analogous to brewing tea. More time = more extraction and more strength.
Leave your tea in the water for too long and it becomes very dark, too strong, bitter and astringent (puckering dry sensation on the palate). Conversely, not enough time will make an insipid, thin and weak brew.
Coffee is much the same.
In the case of espresso, if you brew too quickly, the coffee is not only underwhelming in flavour but it also becomes overwhelmingly acidic and jagged. This is a low-quality acidity is often associated with a perceived sourness.
Conversely, an espresso that takes too long to come out will result in a brew that is strong, bitter and dry.
It’s all in the grind
Assuming constant tamping pressure, the brewing time is largely influenced by your grind size.
Imagine you have two identical pipes of equal length and diameter. The first pipe is filled up with gravel whilst the second pipe is filled with coarse sand. You then try to filter water through both pipes.
One pipe will allow water to flow faster than the other. The gravel, having more space or gaps will allow the water to filter through faster than the sand. And that is, in essence, the effect of grind setting.
Coarser = faster shot time
Finer = slower show time
We recommend you shoot for a time of 25-27 seconds for now.
After dosing in 20 grams and your 40-gram yield came out faster than 25 seconds, adjust your grinder finer, purge out 2-3 seconds worth of grinds and repeat.
If your 40-gram yield took longer than 28 seconds to come out, adjust your grinder coarser, purge out 2-3 seconds worth of grinds and repeat.
Locking down strength
The next step to dialing in espresso after shooting for a basic extraction is to find a strength of espresso that you enjoy.
Strength is a personal preference and entirely your choice. Strength is largely dictated by the espresso yield, the second parameter of the espresso recipe.
Was the espresso you just made weak, strong or just right?
If the strength was just right, then the brew ratio of 1:2 is perfect, you can skip to the next stage, locking down flavour.
If the espresso was weak, pull another shot 2 grams shorter in yield (you may have to grind finer to keep it brewing between 25 and 27 seconds).
If the espresso was strong, pull another shot 2 grams longer in yield (you may have to grind coarser to keep the brewing time down).
Keep iterating in 2-gram increments up or down in yield until you have reached a desired strength. This will become your new target yield.
Locking down flavour balance
Now that we are at your desired strength, it’s time to lock down the flavour balance. This part of dialing in espresso is largely influenced by extraction time, the last parameter of the recipe.
The perfect espresso is neither overly acidic, nor bitter. What you’ll often hear from coffee pros is that they are looking for a harmonious balance of acidity, bitterness and sweetness from the coffee.
It is important to note that equal intensity doesn’t necessarily imply balance. It is how all three aspects of flavour (sweet, sour, bitter) help support one another to achieve an overall flavour balance.
It’s likely you over-extracted your coffee. Grind coarser until the bitterness fades away. This is your new target extraction time.
If your espresso is sour and sharp, it’s likely the espresso is under-extracted. Grind finer until the espresso is balanced. This is your new target extraction time.
Not bitter, not sour?
If your coffee is already balanced, we lucked into the correct brewing time for your coffee, happy days.
You just learnt a powerful system for dialing in espresso. You now have a fully defined recipe that is pleasing in not only strength but also in flavour balance!
As always, if you have any questions about dialing in espresso, let me know in the comments section below. Happy brewing.