There is no exact science for an espresso shot recipe. Since there are so many variables to it, it’s all about finding what works best for you. It can depend on grinder, espresso machine, water, tamp, dose, roast, coffee bean, temperature, air moisture and the list can go on. Here at Redber we work with over 35 different coffees so we try to stick to a more universal espresso recipe. In principle, you need to experiment with what you have, so that you can produce the shot you like.
The Main variables of espresso brewing are:
- Dose – the amount of the dry ground coffee in the portafilter
- Yield – the amount of liquid coffee (espresso) in the cup
- Extraction Time – contact time between coffee and water
- Grind - the size/fineness of the ground coffee
The Dose is the weight of the dry ground coffee in the portafilter, and depending on your espresso style, the dose can be anywhere between 5 and 30 grams. A general modern day espresso is usually somewhere between 18 and 21 grams. The only question is, how much espresso do you want to make? Put simply – a larger dose can make more espresso, and a smaller dose can make less. You will only ever need to change the dose if you want to make more or less espresso. Do not change the dose if you are trying to:
- Adjust the flavour balance
- Adjust the shot time
- Make the espresso stronger or weaker
We use a dose of about 16-18g of coffee and adjust the grind to suit the coffee used. We would match this with a 1:2 ratio of water so 32-36ml for a double espresso. On a domestic espresso machine the portafilter basket could be bigger or smaller so you may have to play with this. As a rule of thumb you should ensure that there is never so much grinds in the basket as to touch the shower screen on the machine.
If you increase the dose, you also need to increase the size (yield) of the espresso to match. If you are making a milky drink you may start off with a tasty espresso, but once you fill the cup with milk it will not be as rich and flavoursome anymore. A larger dose (and larger yield) will then increase the intensity of the coffee flavour in that drink.
Understanding coffee extraction is also an important aspect of any brewing method. You should be looking for a steady pour of about 18-28 seconds. Any faster and you will be under extracting your coffee and any slower and you will be over extracting. There is a huge amount to be said about coffee extraction, but as a rule of thumb note that if your coffee taste is bitter and ashy then you may be over extracting. If the taste is sour and thin, then you may be under extracting. The best way to judge your extraction time is all down to taste. You also Ideally want to have a water temperature between 91-96°c. Any hotter than this and you will burn the coffee.
The grind of coffee used is another variable to consider when extracting, as this will affect the extraction time. A finer grind will have a longer extraction and a coarser grind will have a shorter extraction. Grind is an entirely separate topic in itself which can also be explored.
A Tip for You
If you are experimenting to find the perfect espresso recipe for you and you are constantly changing the dose, then it will be extremely difficult to understand what’s actually happening. Changing dose will affect many variables including: flow rate, puck saturation rate, extraction temperature, extraction yield, strength and extraction evenness. Keeping the dose the same will make adjusting variables and figuring a coffee out a lot easier!