One of the essential parts of espresso brewing is the ratio between the ground coffee and the volume you get out, i.e. the amount of water used in brewing. What is a double shot? Does the amount matter? What does a Ristretto or a Lungo mean? Why choose one over the other? What is the difference in taste? All these questions are linked to the brewing ratio. In this article we will discuss the brewing ratio between ground coffee and the amount of water, and how this can affect the taste and the result. The English author, barista, owner of a roastery, former winner of the World Barista Championships 2007 is a prominent figure in espresso brewing, James Hoffmann has explained in detail in his Youtube video about precisely brewing ratios:
Weighing the amount in volume vs. weight
In the past, espresso has always been measured in volume where a single espresso shot was about 30ml and a double espresso double that at about 60ml. However, this type of measurement is not precise enough to understand how good or bad the result was. Because volume cannot tell if the result of 60ml espresso comes from 18g ground coffee or from 20g ground coffee. Which is a big difference.
Another reason why weighing the amount of espresso by volume is flawed is that it is almost impossible to get the same result by this type of measurement. Because over time the coffee ages and hence the amount of carbon dioxide in the bean decreases. This in turn leads to the formation of less crema on top of the espresso shot. Less crema means that although the volume is the same at 60ml, the weight can be different as the more crema the lighter and vice versa for less crema.
Ratio by weight
Because it is important to measure the amount of espresso by weight based on the amount of ground coffee used in brewing by weight. By weighing the weight of ground coffee as well as the weight of the amount of espresso brewed, an accurate ratio of ground coffee to the amount of water can be obtained. The brewing ratio is a necessary and essential it to get the same result cup after cup and a useful tool to set the espresso machine according to the bean.
Why is the ratio so important?
By brewing with a specific ratio you can get the same results. Not only to be able to reproduce the same espresso, it is an important factor to keep track of how much you extract from the coffee. The more water used in brewing the more is extracted and hence a reduces the strength of the coffee drink and hence the drink will be more diluted. So by finding the right ratio, you can produce a well-balanced espresso that is neither sour nor bitter.
The most common ratios and their meanings
The most common brewing ratios that you will find in cafes are Ristretto, Espresso and Lungo. Ristretto in Italian means limited and is usually brewed at a ratio of 1:1 to 1:15. A traditional espresso is usually brewed 1:2 to 1:2.5 and a Lungo 1:3.
Don't forget that these ratios are not rules carved in stone but simple guidelines. Generally, you tend to start with these guidelines when brewing then experiment until you find a ratio that suits you.