How does the water cut-off method affect the extraction of hand-made coffee?

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If you want to make good coffee, you can not ignore the importance of water quality, water temperature, water quality, chemical composition, water injection methods, etc., will affect the flavor, aroma and extraction rate of coffee extraction.

In this article, let's take a look at the most commonly used water injection technique: water cut-off method. To write this article, the author interviewed Patrik Stridsberg, co-founder of 3TEMP and inventor of Hipster brewer cooking apparatus, to confirm the author's point of view.

The distribution of water varies with different flushing methods.

There are many ways to inject coffee. The simplest way is to directly mix the water with the coffee powder and pour the water into the coffee powder in one go. This method is more suitable for the soaking method, which can ensure that the coffee powder has the same contact time as the water as possible.

As for drip flushing, because the water will continue to flow through the coffee powder, two methods can be used to control the flow.

Continuous Water method:

This method of water injection requires good control of the flow of water (especially when cooking for a long time).

Water cut-off method:

It represents the use of multiple water injections to achieve a specific amount of water, and the amount of water injected each time and the number of times of water injection can be adjusted to experiment with this manual method.

These methods can prevent the coffee powder from rising with the water during the water injection process and avoid the excessive disturbance of the water to the coffee powder. However, the water injection process will still produce a positive disturbance, allowing the coffee powder to move around, thus ensuring a more uniform contact between the coffee and the water. For more information on the relationship between stirring, water injection and extraction, please refer to the following articles:

The hand flushing process can also be filled with water in a circle to help the water flow to soak the coffee powder more steadily and evenly.

Extraction basis

Before we talk about water cut-off, extraction and disturbance, let's take a quick look at what extraction is all about.

Extraction is a delicate balance formed by grinding thickness, baking degree, water temperature, coffee powder amount, water quantity, brewing time and other factors, but simply speaking, it is the result of contact between coffee powder and water.

The more contact, or the more frequent contact (whether through finer grinding, longer brewing time, higher water temperature), the more coffee flavor and aroma substances will be extracted. The less exposure, or the lower the frequency of contact, the less material will be extracted.

Remember to control extraction is the key to delicious coffee, over-extracted coffee will bring bitterness, underextracted coffee will have a sour taste. Uneven extraction will lead to over-extraction and insufficient extraction of elements, this is to explore the importance of disturbance.

The relationship between water cut-off method and spoiler and extraction

The water cut-off method will have an impact on the disturbance and cooking time, he said, citing the Hipster as an example: "We can choose the flow size of the water cut-off method." If the number of times of water injection is less, it means that the amount of water injected each time is more, and the more times of water injection is, the less water is injected each time. If the number of water injection is less, the greater the force of water impact on the powder bed, the shorter the extraction time. If there are many times of water injection, the extraction time must be prolonged. "

In other words, it is not only the amount of water injected and the frequency of water injection, but also the impact of the water.

If the water hits the coffee powder bed with too much force and too much water, the coffee powder will cause too much disturbance, and if the coffee powder is ground too finely, the impact will be even greater, because the lighter the powder will make the coffee powder more likely to be moved.

So what is "excessive disturbance"? For many professionals, the fact that the coffee powder bed is not flat when the extraction is completed is the result of excessive disturbance, and the water will automatically flow to and penetrate the lower density coffee powder, indicating that some coffee powder will be over-extracted. some are underextracted. The best condition is that the coffee powder bed is uniformly distributed before and after the extraction.

"for all brewers, if you want a flat coffee powder bed, the distribution of water will take longer, which means that more water injections with smaller water flows will cause milder water flows to impact the powder beds and form milder disturbances. "

Relationship between Water cut-off method and extraction time and Grinding degree

However, as mentioned earlier, extraction is the result of the balance of many factors, and as long as the flow of the water cut-off method can be controlled, the factors can be changed and the cooking method can be adjusted while eliminating the negative effects.

If you want to maintain the cooking time, but change the grinding thickness. Generally speaking, the grinding thickness will affect the cooking time, and the thicker the grinding will slow down the extraction, because the water flows through the coffee powder faster. However, if it is paired with a smaller flow, the cooking time can be prolonged regardless of the grinding thickness.

"usually you adjust the grinding thickness to adjust the speed at which the water flows through the coffee powder, but if you use the water cut-off method to control the flow, you can reduce the effect of grinding thickness and cooking time on the extraction." "

Consistency and flavor

So is it the best hand flushing method to use water cut-off method with concentric circle water injection? It should be noted that each injection is due to the difference in the brewer's habits and has something to do with who drinks coffee. As long as you remember that the water cut-off method and concentric water injection can form a more uniform extraction, but it is also more difficult to maintain consistency.

Said: "when using hand flushing, it is almost impossible to make every cooking the same, only a very small number of people can achieve complete control." "

In addition, he points out, "hand brewing allows you to combine water and coffee in any form you like." If we use a regular coffee machine, we can only turn on the power and have no control over the size of the water flow. On the other hand, if you flush it by hand, you can have more control over the flow of water, but you can't completely maintain the consistency of cooking. "

Which is more important, "control or consistency"? It depends on the situation when you make coffee. Are you going to make your own coffee? Or do you want to train baristas from stores with good business? Are you going to race? All these determine the nature you value.

Water flow distribution is only one of the many factors that affect coffee extraction. Try different methods, find out what works best for you, and have the courage to try the new changes brought about by each cup of coffee.