Today we’re going to talk about espresso ratios, what they are, how they affect the flavour of your espresso, and which ratio you may want to use according to the coffee you are brewing and your taste preferences.
What is an Espresso Ratio?
So, espresso ratio refers to the amount of dry coffee you are using vs the amount of extracted coffee liquid, or espresso, you end up with in the cup. These are typically weighed in grams and written as coffee dose:espresso output. So a 36g shot of espresso pulled from 18g of coffee grounds would be a 1:2 ratio.
Along with grind size, pressure, temperature and time, ratio is one of the fundamental aspects of brewing coffee and makes a huge impact on the concentration and taste of your beverage. The more water that passes through the coffee, the more of the coffee flavours you’ll be able to extract, but the more dilute your final beverage will be.
What this means is that an espresso with a short 1:1 ratio, will be a very concentrated drink, often referred to as a ristretto, but won’t be very strong in terms of the amount of coffee it has extracted. Compare this to a more dilute espresso at a 1:3 ratio, the drink itself will be quite dilute as far as espresso goes. But, with more water passing through the bed of coffee, the overall extraction will be higher.
So, if you take a look at an espresso whilst it’s brewing, the initial liquid coming out of the portafilter is very dense and concentrated, but overall not much coffee has been extracted. As the brew continues and ratio increases, the liquid becomes more and more dilute whilst the total extraction rises continually higher and higher.
Now I totally understand if this is confusing, especially if you’re used to the idea that a ristretto is ‘strong’ and a lungo is ‘weak’. Whilst not incorrect, that doesn’t tell you much about the extraction or flavour of the drink.
Next, we’ll talk about how you can use and adjust ratio to affect the flavour of your espresso.
How does espresso ratio affect flavour?
So we’ve learnt that ratio can directly influence the overall extraction of your coffee, but why is that useful to know? If longer ratios can help me extract more flavour out of my coffee, I should use that every time right?
Well not necessarily. Not all of the flavours available to be extracted are desirable, and ones that you want in your coffee. Different coffees might taste best at different levels of extraction.
If you’re a fan of light roasted filter coffees, you probably know that you need to use high temperatures and often long contact times to get the most flavour out of the grounds. These coffees haven’t had much time to develop inside the roaster, and therefore require more effort to extract flavour during the brew. These coffees tend to benefit from longer ratios too, to get higher levels of extraction, so a great place to start with light roast espresso is a 1:3 ratio.
If you want to know a bit more about what it takes to extract lots of flavour from light roasted coffees, check out our light roast aeropress recipe.
For other coffees, you might not want to extract all of the flavour. This is true of dark roasts that have more bitter compounds. They have had more time to develop and break down in the roaster, so give up their flavour more easily. You might therefore want to shoot for a lower extraction by using shorter ratios, to the bitter compounds. This is why you’ll commonly see traditional Italian espressos brewed with high doses of coffee and a small amount of liquid in the cup, like a ristretto. For dark roasts, you might want to aim for something like 1:1 or 1:1.5.
So, a quick recap on which ratio you might want to use according to the coffee you’re starting with
A good place to start would be 1:1 for dark roasts, 1:2 for medium, and 1:3 for light roasts. If you’re someone who enjoys having a very small shot of espresso, you’ll probably have a better experience with darker roasts that will be nice and balanced at shorter ratios, whereas if you don’t mind sacrificing a bit of texture and strength you can have a great time with lighter roasts.
How to Dial in Espresso Using Ratio
Once you know how ratio affects extraction, you can start dialling it in to improve your coffee. It’s really useful to know how to use ratio to fine tune and dial in your coffee, because dialling by grind size might not always be an option.
If you’re using a grinder that doesn’t quite let you grind fine enough, or your using pre-ground coffee and you have to deal with whatever grind size you’re given, you can use ratio to fine tune the flavour. If the coffee is underextracted, maybe it’s sour or just has very little flavour, you can decrease the dose of coffee or aim for a higher output to increase extraction rather than grinding finer.
So for example if I’m using a 1:2 recipe of 18 grams of coffee to 36g of espresso, but it’s coming out too quickly and for whatever reason I can’t adjust the grind size, I can try increasing the dose to 18.5g to slow down the extraction and increase contact time.
Once you have some decent experience and have built up the intuition for how an espresso should look and extract from your machine, you can also start to use it reactively during the extraction.
If you see your espresso is flowing too fast out of the portafilter and you get your desired output weight too quickly, you could try letting the ratio go a bit longer and letting more water through the puck to avoid underexactraction. It will be more dilute, but has more of a chance of being tasty instead of stopping at your desired output and being underextracted.
The same is true the other way round as well. If you’re aiming for a 1:2 ratio in 28 seconds, but the coffee is coming out slower than usual, you may want to stop the shot early and aim for less liquid in the cup to avoid over-extracting.
So I hope that’s been helpful, if you want to learn more about dialling in espresso you can check out our guide to espresso grind size.