How to control the relationship between extraction time and pressure of conscious espresso

How to control the relationship between extraction time and pressure of conscious espresso

1. Too rough grinding: if the flow rate is too fast, more than 60 milliliters of coffee will be extracted in less than 20 seconds; the concentrated color is light yellow, the texture is thin, and the oil is maintained for a short time; the taste is high acidity, simple taste and heavy water feeling.

two。 Over-fine grinding: the flow rate is very slow, more than 30 seconds of extraction time, can not extract more than 50 ml of coffee liquid; the color is dark brown, thick; taste bitter, irritating. After the extraction, "a depression of water" is likely to appear on pressed powder, because the water can not pass smoothly through the powder layer and is silted on the surface of pressed powder.

Suggestion: usually in the production of Italian style, you can often use your hands to twist and rub the grinding powder thickness, memory powder thickness feel, convenient to quickly judge the direction of grinding degree adjustment.

The most common mistake people make is too short extraction, because most coffee lovers who are reading this article are not very receptive to gray or bitter taste. Unfortunately, too short extraction is likely to sacrifice sweetness. Coffee, as always, always asks us to make compromises.

Extraction area (Surface Area)

Increasing the contact area between coffee and water makes it easier for water to extract flavor substances. When you grind the coffee into powder, the surface area of the coffee increases exponentially.

You can think of coffee beans as a cube with a side length of 1cm, with six faces, each with an area of 1cm2, so the surface area of this cube is 6cm2.