Basic knowledge of coffee: what is the general extraction time of hand-brewed coffee?

Qianjie noticed that when many friends first came into contact with hand-made coffee, they attached great importance to the amount of brewing powder, the proportion of powder to water, water temperature, manipulation and grinding, but the extraction time was probably enough. This is not gonna work! Extraction time is very important!

Why is extraction time so important?

Only 30% of a coffee bean is soluble flavor, and the other 70% is wood fiber, so the flavor of coffee is not long.

In the process of extraction, the first stage of extraction will dissolve the small molecular flavor substances (sour and sweet taste) in coffee particles to the maximum extent, which determines the taste and aroma of coffee. In the latter stage, the extraction begins to dissolve the macromolecular flavor substances (bitterness) in the coffee particles, and these heavier flavor substances can increase the alcohol thickness of the coffee when released properly, and if excessive release, it will bring bitterness to the coffee.

This means that when other parameters remain the same, the longer the extraction time of coffee is, the higher the concentration of coffee is, the more macromolecular flavor substances will be in the end, and the whole coffee will show strong and bitter; if the extraction time is too short, the concentration of coffee is lower. Only small molecular flavor substances are extracted, and the coffee as a whole shows sweet and sour and thin.

In hand-brewed coffee, each factor is related to each other, so there is no fixed standard for extraction time, but there will be the best range. According to Qianjie's brewing experience, if you want to get a cup of hand-brewed coffee with the right flavor, the best total extraction time for 15g coffee powder is 1 minute 50 seconds-2 minutes 20 seconds.

Does the hand timing start before or after steaming?

The best total extraction time just mentioned in front street is from the moment the water comes into contact with the coffee powder. Take freshly roasted and raised beans as an example, grind into coffee particles of suitable thickness and then inject twice the amount of water (15g powder into 30g water). The best steaming time is 30 seconds from the beginning of water injection.

During these 30 seconds, coffee particles will release a lot of carbon dioxide and sweet and sour flavor substances. If we start the timing for 30 seconds after water injection, it will actually prolong the steaming time, because it usually takes 8-10 seconds to inject 30g of water. If you make light roasted coffee beans, the 10-second gap is likely to make the coffee feel astringent.

What are the factors that affect the extraction time?

/ influence of coffee filter cup

The design of the angle, rib and shape of the coffee filter cup will affect the speed of the water passing through the coffee layer, and the extraction time will be fast and slow. For example, the V60 filter cup, the spiral long rib design and the bottom large aperture filter hole will make the water pass through the coffee powder layer faster and the extraction time will be shortened.

For example, the Kono filter cup, the design of short ribs only extends to the filter cup 1 to 3, and the part without ribs can be sealed with the filter paper, which slows down the speed of water passing through the coffee powder layer and prolongs the extraction time.

/ coffee grindability

The finer the coffee beans are ground, the tighter the space between the coffee particles, the slower the flow rate of water, and the longer the extraction time. Too long extraction will lead to excessive release of flavor substances, causing the coffee to become strong.

The thicker the coffee beans are ground, the larger the gap between the coffee particles is, the faster the flow rate of water is and the shorter the extraction time is. Too short a time of extraction will not have time to dissolve the flavor substances, causing the coffee to become boring.

/ thickness of powder layer

Take V60 filter cup as an example, No. 01 filter cup is suitable for brewing 15-20g coffee powder and No. 02 filter cup is suitable for 20g-30g coffee powder. (the same bean under the same grinding degree) too much powder into the No. 01 filter cup, the powder layer will become very thick, increase the resistance of water flow, and the extraction time will be prolonged; if too little powder is put into the No. 02 filter cup, the powder layer will become very thin, reducing the resistance of water flow, and the extraction time will be shortened.

/ method of water injection / method of washing and cooking

When brewing hand-brewed coffee, the number of segments injected and the flow of water will affect the extraction time. For example, compared with three-stage water injection, the more the number of stages, the longer the extraction time.

When using small flow water injection, the overall liquid level in the filter cup will not be greatly improved, the powder layer distributed on the cup wall is thicker, and the extraction time will be prolonged; when using large flow water injection, the overall liquid level in the filter cup will be greatly increased, and the powder layer distributed on the cup wall will be thinner, and the extraction time will be shorter.