Introduction to the extraction method of gold in coffee: the ratio of water to powder

Coffee extraction ratio

Insufficient extraction: coffee solids are not extracted enough to produce a light, boring aroma. Visually, it is a fast and large-volume extraction, and coffee oil is a uniform light yellow tiger spot and miscellaneous spots: the main visual cue for good extraction. The tiger spot is formed by the contrast between dark and light coffee oil in the coffee stream; ideally it appears at the beginning of the coffee and lasts until the end. "variegated spots" are the performance of good extraction in the cup; it refers to the dark brown pre-wetting (Pre-infusion) formed on the surface of coffee oil: the act of pre-infiltrating coffee powder inside the espresso machine before the coffee is actually extracted. Some coffee machines are achieved through pumps; the pump works for 1 / 2 seconds and stops for 1 / 2 seconds. Then start again and continue to extract coffee. Fully automatic machines and some automatic machines use this method. The other is called "natural" or progressive prepreg, and this is the kind of machine with E61 outlet head. After the pump starts, the pressure is completely applied before the coffee cake, and the second cavity must be filled. The soaking time of coffee powder was 3-7 seconds before the pressure was established. This kind of prepreg is more popular. There is a truckload of theories that progressive pre-wetting can improve coffee extraction overextraction (Over-extraction): too much coffee solids are extracted to produce a strong, irritating aroma. Visually, the capacity of coffee is insufficient, and coffee oil is a thin layer of blackening. The dark black circle on the edge of the cup is another typical indication of over-extraction or high water temperature gold (extraction) rate (Golden rule): a common term that describes the ideal time and capacity for extracting espresso. The Italian National Coffee Institute (Instituto Nationale Espresso Italiano) provides a practical definition of the ideal espresso properties, although these parameters are more like the "golden rule" than mandatory rules. The simple definition is: use about 16-18 grams of coffee to produce 60 milliliters of double espresso oil (Crema) in 22 to 27 seconds (from the outflow of the coffee liquid): make sure that espresso makes the appropriate signal (on a coffee machine where the oil is not forcibly produced), the result of various gases-air and carbon dioxide-distributed in the water under high pressure. The liquid also includes emulsified oil. A deep golden brown east-west channel effect (channeling) is formed on the surface of espresso: water flows rapidly through the cracks in the coffee cake, resulting in a thin, underextracted espresso. When this happens, a yellowing stripe is often seen in the coffee stream; sometimes the channel effect leaves a pencil lead-sized hole in the coffee cake. Coffee extraction is very knowledgeable, especially in the production of espresso. Here are some terms that professionals often use when talking about coffee extraction. Let's learn the following.

Blonding: describes the conversion of the liquid from dark brown with tiger stripes to uniform light yellow. This usually occurs in the last 1amp 3 stage, indicating that the extraction operation can be ended. The excessive yellowing part of espresso has a light taste and almost no aroma. If it lasts too long, it will dilute the mellowness and is no longer a pleasant taste.