The most common concept of espresso in Europe and America

The amount of extraction is inversely proportional to the extraction time.

The more the amount of extraction, the shorter the contact time between coffee powder and hot water (avoid over-extraction).

On the contrary, when the amount of extraction is reduced, the contact time between coffee powder and water should be increased (to avoid insufficient extraction)

Al formula: when the extraction amount of 5cc is increased, the extraction time should be subtracted from 1sec. On the contrary, add 1sec.

For example, when the amount of extraction increases to 45cc, 30-(45-30) / 527, the extraction time is reduced to 27sec.

When the extraction amount is 60cc, the extraction time becomes 24sec.

Within the reasonable limit of 0.75-2.5oz Espresso, this formula can quickly and correctly hunt sweet spots (Sweet Spot), effectively catch satisfactory ingredients, and maintain a scary balance between over-extraction and under-extraction. The main means of control is to adjust the grinding thickness.

Ristretto is a very different drink from normal espresso.

If the grinding is constant and the extraction is finished early at the normal espresso flow rate, for example, at the original 30sec/ 30cc flow rate, only 25cc is taken, which is the result of insufficient extraction in a cup, because the sweet point has not yet been reached.

The so-called ristretto means restricted, and the customary practice is 25cc/ 30-35sec.

All sensory sensations, including what the eyes see, what the nose smells, and what the tongue tastes, whether it's good or bad, are aggravated.

Ristretto is characterized by a very thin mouse tail with a darker brown crema.

Most people don't drink this stuff every day, but it's good for blend, which is still in development.

If you are the one who is used to drinking ristretto, whether it is 25cc or 50cc, then your grinding should be adjusted accordingly. How to adjust? It's the same, Al' Rule. Let's start over.

Al is equivalent to reiterating that his formula is based on the data made by single basket at the beginning of setting work. That is, even if your store usually uses the double filter to make cups, the single filter is still the set benchmark. In his personal experience, no espresso (single) should be less than 25cc. For him, a glass of 15cc espresso is unable to reach the "drinkable" state (the word drinkable is still a long way from being good), which is tantamount to giving advance advice to some people who like 30cc double ristretto later.