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 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 have learnt a very powerful system for dialing in espresso and gain a deeper understanding and appreciation for the nuances of coffee.
Welcome to the ultimate guide to dialing in espresso for newbies.
Table of Contents
- The Espresso Recipe
- Locking down strength as a preference
- Locking down flavour balance
The espresso recipe
Every espresso 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 of soluble flavour and aromatic compounds into our brewing water to make a delicious coffee.
To control the rate of extraction (how quickly we pull flavour out from the coffee grinds) and the final strength of our espresso, we must consider three basic parameters in the espresso recipe; dose, yield and time.
These three parameters on their own have a huge impact on any extraction and are independent variables.
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 or where the coffee came from), climate, variety, processing method, roast solubility, water source and equipment. Whilst we don’t have any control over most of the factors listed, what we can control is what we do behind the machine.
For example, the perfect recipe for one Kenyan SL-28 (a variety of Arabica coffee) coffee might not necessarily translate well to another SL-28 coffee from the same region. It’s similar to how different winemakers in close proximity to one another can produce wildly different wines from the same variety of grapes.
Let’s break down the recipe into its components.
Dose – how much ground coffee
The dose or dosage refers to how much ground coffee is being used in our brewing system.
A larger dose will allow you to brew more espresso and a smaller dose will yield less espresso. Espresso recipes generally speaking can be scaled – more on this later when we talk about yield.
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 dose and yield. This scale has a resolution and accuracy of 0.1 gram up to 2,000 grams and is perfect for our purposes.
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. If you are unfamiliar with these steps, our Espresso Basics barista course covers these topics in great detail.
We are now ready for brewing.
Yield – how much espresso is in your cup
The yield refers to the total output of espresso from the machine, or how much espresso is in your cup/s.
The yield has two properties we can measure; namely volume and mass. The preferred method for measuring yield is weighing the espresso’s mass for ease of measurement and consistency.
Brew ratio and its effect on strength
The Brew Ratio is a concept that defines the relationship between the dose and the yield.
For regular espresso, this ratio is usually at or close to 1:2. A 1:2 ratio means for every gram of coffee in your basket, you will yield 2 grams of liquid espresso.
Think of brew ratios as a scaling factor. If you have more dose, you can make more espresso – within reason, of course. The physical limitation here is the filter basket size.
For example, a 20-gram dose at 1:2 would yield a 40-gram double espresso. 18 grams in, yields 36 grams out. 25 grams in, 50 grams out etc. Simply multiply your dose by 2. You get the idea!
At a ratio of 1:1 you’re in ristretto territory; thick, heavy, strong and usually under-extracted.
At 1:3 you’re in lungo land; thin, delicate and weak.
Keeping a fixed-dose, changing your yield (and therefore brew ratio) will change your extraction and strength.
As you start to pass more water through a fixed amount of ground coffee, you are able to increase the extraction (dissolve more flavour from the coffee), but at the expense of strength. The extra water that was used to extract more flavour also ends up diluting the brew (lowering the strength).
The opposite is also true, if you pass less water through your dose, you’ll end up with a brew that is stronger but less extracted.
We recommend a starting at a brew ratio of 1:2 and working up or down from there. In our example, the target dose of 20 grams in means our target yield should be 40 grams out.
To achieve this, you will need to pass water continuously through the grinds until the espresso in your cup/s has reached the target yield. Measurement of yield is always done in-situ during brewing, so whip out those trusty scales again because it’s time to brew.
If we actually brew the coffee, what you will notice is that if you cut off the shot when the scale reads 40 grams, the drips of espresso at the end will contribute to your final yield causing you to overshoot the target by a few grams.
You must offset this by cutting your extraction off earlier by exactly this amount of overshoot.
The drip offset is usually somewhere between 2-5 grams depending on what your machine and grinder are and what coffee beans are used.
At a hypothetical 4 gram offset, cutting off the extraction at 36 grams will allow the drips to bring the final yield up to our target of 40 grams.
Time – how long it took to brew
Time is the final piece of the puzzle in our recipe and can be thought of as two ways:
- how long it took to reach the target yield from the moment you press the button on your machine OR
- the total time the coffee grinds spent in contact with the water
Time is a driver of 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 low-quality acidity is often associated with a perceived intense 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 – how coarse or fine you grind the beans.
Imagine you have two identical open-ended pipes of equal length and the same 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 much 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 as a preference
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 your 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 baristas 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) interact and help support one another to achieve overall balance and a flavour profile.
It’s likely you over-extracted your coffee. This means you dissolved too much flavour from the coffee.
You’ll need to lower your shot time. Grind coarser and extract again keeping your dose and yield the same 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. This means you left a lot of flavour behind in the grinds.
This is fixed by increasing extraction time. Grind finer and extract again keeping your dose and yield fixed 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.
More dose = more espresso
Less dose = less espresso
Once you’ve locked in your dose:
More yield = more extracted but weaker
Less yield = less extracted but stronger
Once you’ve locked in your dose and yield:
Finer grind = more contact time = more extracted and stronger
Coarser grind = less contact time = less extracted and weaker
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.