How to judge the quality of dregs coffee machine espresso espresso with coffee beans

We all know that it takes water to make espresso. The water is heated by a boiler and drenched vertically from the top of the pressed powder. When you press the outlet button, the water will continue to flow out and fill the gap between the pressed powder and the outlet, and only after the gap is filled can the water begin to gradually go deep into the pressed powder and begin to extract.

In the process, the water will soak all parts of the pressed powder. Once the coffee machine stops coming out of the water, the pressure inside the coffee machine gradually decreases, because there is not enough pressure, the remaining water can not penetrate pressed powder, it will remain in the gaps on the surface of pressed powder.

After the production is finished, if you remove the handle quickly, the remaining water will slowly seep into the discarded cake under the trend of gravity. After a few seconds, the cake will absorb all the remaining moisture.

The less the powder, the more water in the void, and the cake will be looser and wetter.

The more powder, the less water in the gap, and the cake will be more compact and dry.

If after powder pressing, the gap between pressed powder and the outlet is larger, the remaining water will be a lot, so the cake will be more loose. If you are using a VST filter bowl (this is the one I use! You will find that the height of this filter bowl is higher than that of other kinds of filter bowls. The original purpose of this design is to prevent coffee powder from coming into direct contact with the outlet. Pressed powder direct contact with the outlet will lead to uneven coffee extraction, so you must leave a certain gap between pressed powder and the outlet. So I dare say that a loose pressed powder is much better than an over-tight pressed powder, because at least the coffee is extracted more evenly!