Un articolo di Ars Technica discute un modello matematico sviluppato da alcuni scienziati per realizzare un espresso migliore con meno scarti.
There’s actually an official industry standard for brewing espresso, courtesy of the Specialty Coffee Association, which sets out strict guidelines for its final volume (25-35mL, or roughly one ounce) and preparation. The water must be heated to 92° to 95°C (197° to 203°F) and forced (at a specific pressure) through a bed of 7 to 9 grams (about a quarter of an ounce) of finely ground coffee over the course of 20 to 30 seconds. But most coffee shops don’t follow this closely, typically using more coffee, while the brewing machines allow baristas to configure water pressure, temperature, and other key variables to their liking. The result of all those variations in technique is a great deal of variability in quality and taste.
Immagine da Luis Macalinao – Flickr.