Ristretto is an Italian term meaning “shortened” or “narrow”, or the equivalent of a café serré in French. What is used to describe an espresso, is the complete opposite description for what a ristretto entails.
The coffee to water ratio between a ristretto is about 50% less water than that of what is in an espresso. As a result, ristretto is typically stronger than its counterpart as there is less water in the cup to dilute the strength of the coffee. Since there are not as many flavors that are being diluted, the overall flavor of the coffee is more balanced; the flavors are equally blended together.
HOW IT IS MADE
Espresso shot is used to make a ristretto, but while there is the same amount of coffee in the cup there is much less water quantity (about half of as a regular espresso shot). The ground coffee is pulled through a fine grinder, called a portafilter, to produce a more concentrated cup of coffee. Because the shot is pulled short, it differs from a regular espresso in both taste and the chemical composition. It differs in terms of 3 main components: different balances, concentration levels, and has fewer total extracts. Ristrettos are usually drunk as they are without the addition of milk or more water, giving the brew a bolder feel. Compared to espressos, ristrettos are not as bitter.
HOW MUCH CAFFEINE IS IN A CUP OF RISTRETTO
Since a ristretto is filtered through a portafilter multiple times before it reaches your cup, there is typically less caffeine inside each cup. All of the oils, salts, and minerals that are found in the coffee bean are reduced since they were filtered multiple times. Compared to an espresso, which is typically served in a 30 ml cup, a ristretto is served in a 20 ml cup, leaving less room for caffeine. A Single ristretto shot could have around 33mg of caffeine, whereas a double ristretto shot would have 66mg of caffeine.