In pour-over coffee, even if it is the same bean, the difference in extraction equipment and extraction methods will make a huge difference in the flavor of the coffee.
Conventional extraction methods are mainly divided into two types, immersion extraction and trickle extraction. So what is the difference between the two? Let's chat today~
What is Immersion Extraction?
Immersion extraction refers to adding all the extraction water at one time, and extracting the substances in the coffee through the brewing method of fully contacting and soaking with the coffee powder layer, and finally filtering the coffee, that is, extracting first and then filtering.
What is trickle extraction?
Drip filter extraction means that new water will continue to pass through the ground coffee layer and drip into the cup after being filtered. To put it simply, it is to extract and filter at the same time, and the two are carried out at the same time.
What is the difference between them?
01 The utensils used are different
First of all, the choice of equipment is different, and the extraction method will naturally be different. The brewing methods using immersion extraction mainly include cupping, smart cup, French press, Aeropress, siphon pot and so on. The brewing methods using drip filter extraction mainly include hand-dripped coffee made of various filter cups, American drip filter machines, and so on.
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But there are also a small number of appliances that can combine immersion extraction and drip extraction, such as smart cups with valves, or AeroPresses that use back pressure methods, etc.
Therefore, we can also find that the same bean is brewed with different coffee equipment, and the taste will be very different, because the extraction methods they use are actually different.
02 Different brewing styles presented
We used a washed Yunnan coffee bean to test the taste. When the water-powder ratio and extraction rate are basically the same, the coffee extracted by immersion will have a more peaceful, round and clean taste. However, the coffee brewed with the V60 filter cup with one knife has a stronger sense of flavor layering, a stronger aftertaste, and a longer aftertaste.
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This has a lot to do with the uniform and stable extraction characteristics of immersion extraction. Immersion extraction is less subject to human interference, so when adjusting parameters, it can also better control variables.
However, the trickling filter extraction has many human interference factors, such as the stirring of the powder layer, the speed and range of the circle, the size of the water flow, etc., it is difficult to make the brewing process exactly the same every time. But the advantage is that you can explore more flavors of the coffee beans themselves by adjusting these parameters and brewing techniques.
03 Different extraction efficiencies
The extraction efficiency here does not refer to the extraction rate, which are two completely different concepts. Extraction efficiency refers to a dynamic effect of the extraction process, while extraction rate is a result.
During immersion extraction, the concentration of solubles in the coffee increases rapidly when the water is first injected, and then continues to increase the extraction at a slower, gradual rate. When a certain amount of water is injected, the entire extraction process will be at a relatively low concentration difference, so the substances in the coffee will not be extracted so easily.
In the drip filter extraction, because new water continuously enters the coffee powder layer, the entire powder layer will maintain a relatively high concentration difference. During the entire extraction process, new substances will be continuously extracted.
Therefore, under the same conditions, the extraction efficiency of soaking type is lower than that of dripping type. For example, if the ratio of water to powder is the same, if you want to get a similar extraction rate, the extraction time of the immersion type is often slightly longer than that of the drip filter type.
Considering that the extraction methods of the two are different, we also need to adjust when calculating the extraction rate. Due to the characteristics of the immersion extraction equipment, the amount of injected water may not be completely filtered out. If you want to obtain a more accurate extraction rate, you must add the weight of the water absorbed by the coffee grounds when calculating.
How should they be chosen?
Soaking and trickling filtration have their own characteristics, so there must be friends who want to ask, how should I choose? In general, the extraction quality of the immersion method will be more stable and uniform; the filter extraction method can better enhance the complexity of the coffee flavor.
But more importantly, it is necessary to understand the principles and logic of different extraction methods, and understand the differences in the taste styles produced by them. Then make a choice based on the characteristics of the coffee beans you have in hand and the final flavor you want the coffee beans to present.
In fact, both are very playable, and you can even combine their respective advantages through some tricks to obtain a clean taste and clear flavor direction at the same time.
There is never any difference between the two brewing methods. Even for the same type of beans, there are many suitable brewing schemes. The most important thing is to find the one that suits you best.