Analysis of common problems in hand-brewed coffee extraction: Why does hand-brewed coffee separate from powder and water

Generally speaking, after steaming, while the water current drives the coffee powder to roll, the upper liquid level will be covered by rich golden foam, and a powder wall will be built in an orderly manner on the edge of the filter cup, visually revealing the entire The pace of extraction is progressing steadily.

However, many friends found in the middle and late stages of making coffee that all the coffee powder was constantly accumulating at the bottom, but the water was abnormally floating on it with a fragmented layer of foam. After all the coffee liquid was dripped, filter the cup. Only flat powder pits were left. This is the situation of "powder and water separation" that many people have reported back to Qian Street, so they want to know what is going on and how to solve it?

Under what circumstances will "powder-water separation" occur?

Generally speaking, if the extraction time is within a reasonable range (about 2 minutes), the rate at which we inject water should be relatively consistent with the rate at which the coffee liquor flows into the sharing pot. When the coffee powder and hot water are separated from each other, or more accurately, the coffee powder is on the bottom and the water is on the top, which means that the channel of hot water is blocked, making the amount of water injected much larger than the amount of water injected, and the hot water in the filter cup will increase. More, the extraction time will also be forced to lengthen. There are three reasons for this situation:

1. The density of coffee beans is high

High-density coffee beans are mainly characterized by their tight structure and high hardness. They are generally produced at high altitudes and are lightly baked. Because of their high density, they are more likely to sink to the bottom during the brewing process, thus blocking the hot water. The way.

2. Grinding too fine/too much extremely fine powder

Qianjie often mentioned that when brewing lightly roasted coffee beans, in order to highlight their flower and fruit aroma, it is necessary to increase the extraction rate. It is recommended to use finer grinding, so the particles will be correspondingly finer than medium and deeply roasted coffee.

When brewed high-altitude and lightly baked beans, their hardness is high, and during the "crushing" process, more very fine powder will be brought, such as Qianjie. Sun-cured Huakui (2250m, strawberries, berries), Qianjie. Sidama Hamathiu (1920m, magnolia, guava), Front Street. Coffee beans such as fruit tintin (2000m, citrus, green tea) often experience powder and water separation.

In addition, the amount or amount of fine coffee powder is also affected by the grinding quality of the bean grinder. The worse the precision of the equipment, the more fine powder there will be. When the finer coffee powder blocks the gap in the filter paper first, water accumulation occurs.

When you are often troubled by this phenomenon and want to improve your brewing skills, it is recommended to consider upgrading your equipment before buying good coffee beans. The way to judge is to look at the coffee grounds after you have washed them. If they have both large particles and muddy fine powder, it means that the grinding quality of the bean grinder cannot meet the requirements. The best solution is to change to a better precision bean grinder.

3. The coffee beans are not fresh

The fresher the coffee beans, the deeper the roasting degree, the more obvious the expansion and exhaust of the coffee steaming and extraction are. On the contrary, when the coffee beans are not fresh, there is almost no reaction between the steaming and extraction, because the coffee powder is no longer exhausted and the water flow is difficult to drive the operation, so it can only stay on the surface, and the coffee washed out in this way also obviously lacks aroma. However, compared with the first two points, this situation is very easy to rule out. The baking date exceeds 50 days means that it is no longer new.

4. Problems with water injection techniques

When you notice that the flow rate at the front of the brewing is smooth, and the flow rate slows down as you go to the back, you can only watch as the time exceeds two minutes. This kind of situation is usually caused by the fact that the water flow is too small in the early stage, especially when brewing lightly baked beans. After steaming, the flour layer cannot be raised. In the later stage, the coffee powder is blocked at the bottom of the filter cup. At this time, no matter how hard the water is injected, it is difficult to "save" the flow rate.

In this regard, Qianjie suggested that when brewing lightly baked beans, after steaming, the first section should be injected with large water flow in a circle, penetrating the entire powder layer hard until the liquid level reaches 2/3 of the filter cup. This can drive all the particles to rotate, allowing the coffee powder to come into more full contact with hot water, while preventing extremely fine powder from accumulating at the bottom, thereby reducing the occurrence of clogging.

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473