Brew ratio

Why weighing the coffee is a more accurate way then measuring by volume? 

An espresso is typically defined as a small liquid extracted under pressure by an espresso machine at approximately 9 bars. For a single the volume is about 30 ml and 60 ml for a double. So far, so good, but there is a problem with this way of measuring and the nature of coffee especially in regards to espresso. 

A cup of espresso contains a lot of oils and CO2 also known as crema. The amount of crema varies a lot, and is influenced by the type of coffee, freshness, time in the cup, pump pressure, special types of portafilters and so forth. Thus, the amount measured by volume may vary a lot and the volumetrically way of measuring the coffee often isn’t ideal especially when communicating about coffee to others. That is also why some specialty coffee roasters are starting to use the term brew ratio or dose and brewed weight, in a way to help the customer achieving a better cup.

Actually the term brew ratio is very simple. It’s the ratio between the dose and liquid in the cup. If you for example dose 18 grams of coffee in your portafilter, brew for 25 seconds and weigh the amount of espresso in the cup to 36 grams, the brew ratio is 50%. Some also use the brew ratio in trying to define what characterize a ristretto, espresso and lungo. The typical cut offs are as follows: lungo = 25%, espresso = 50% and ristretto = 100%. 

While you could argue about the cut offs, it’s a great way to achieve a better understanding about your espresso brewing.  So if you want to take your barista skills to the next level, try weighing your coffee.