ristretto

Ristretto is a very short espresso shot, extracted with the same dose of ground coffee as a standard espresso (7 to 9 grams) but with only half the water volume, yielding about 15 to 20 milliliters of intensely concentrated liquid. The extraction stops at the point where sweetness and aromatic oils have been drawn through the coffee puck but before the more bitter compounds follow. Baristas describe it as the heart of the espresso, the first fraction of extraction before dilution begins. The word is the past participle of the Italian verb ristringere, meaning to restrict, to narrow, or to reduce.

Ristringere comes from Latin restringere, built from re- (back, again) and stringere (to bind, to tighten). Stringere gave Italian stretto (narrow), English strict, and by extension constrict, constrain, and restrict. The musical term stretto, used in counterpoint to describe a fugue passage where the subject is compressed in time, shares the same root. In Italian cooking, ristretto also names a reduced sauce, one boiled down to concentrate flavor, which is exactly what the espresso preparation does with water.

Angelo Moriondo of Turin patented an early espresso machine in 1884, and Achille Gaggia refined the high-pressure extraction technique in Milan in 1948. Gaggia's machine operated at 8 to 9 bar of pressure rather than the 1.5 bar of earlier steam machines, forcing water through a tight grind in under 30 seconds. That short extraction window allowed baristas to stop the pull deliberately early, and ristretto became the term for that deliberate restraint. The Istituto Nazionale Espresso Italiano later codified the ristretto in its technical guidelines as a 15 to 20 milliliter extraction.

Third-wave coffee culture, which spread from Seattle and Melbourne in the 2000s, made ristretto pulls fashionable as a base for milk drinks. A flat white built on ristretto shots became a standard menu item at specialty cafés from London to Tokyo by 2012. The concentrated intensity of ristretto holds its character through steamed milk in a way that a standard espresso does not, because less water means fewer soluble solids competing with the milk's sweetness. The word entered English café menus directly from Italian, unchanged, because no English equivalent existed for deliberate early extraction.