The streets are full of explanations on how to brew coffee, but do you know the real reason why are the taste changes depending on how you brew coffee?
There are two main ways to make coffee
There are various coffee extraction methods, but they are roughly divided into two types based on their basic principles. One is a type in which coffee powder and water used for extraction are mixed at the same time, and the other is a type in which a layer is formed with coffee powder, and water is passed through it. The former is called ” immersion/extraction “, and it may be subdivided into those that are boiled while heating directly over a fire and those that are simply soaked in water or hot water, but the extraction principle itself is the same. This includes coffee siphons, press-type coffee, and Turkish coffee. On the other hand, the latter is called ” transparent extraction “, and drip, espresso, Dutch coffee, etc. are this type. Black tea is a typical soaking extract. If you want an alternative coffee, visit mudwtr review.
The basic principle of immersion extraction
Now, from here on, it’s a bit like a high school physics exercise, but in order to understand coffee extraction, I’d like to replace it with a simplified theoretical model and think about its basic principles. Let’s start with immersion extraction, which has a relatively simple principle. As a model, after putting a certain amount of coffee powder and water (hot water) in a cup at once, take out the liquid at regular intervals while stirring, and adjust the concentration of one component (referred to as component A) in it. Consider an experiment to measure. In order to simplify the story as much as possible, we will ignore the water absorption of powder, the bias of component concentration, and the interaction between components. At the start of extraction, the entire amount of component A is present in the flour, which gradually moves into the water. One thing to keep in mind here is that no matter how long time passes, not all component A will be transferred to water 100%. In fact, during extraction, component A not only moves from flour to water but also from water to flour. This is the part that is different from the “dissolution” that dissolves salt and sugar in water, and in physical chemistry, this phenomenon is called “distribution”. This example is called “two-phase partitioning” because the component is distributed into two phases, powder, and water, or “solid-liquid partitioning” because it is a partition between solid and liquid.
Drip type is chromatography
The explanation so far may have come to the fore if you have studied analytical chemistry at university. In fact, this model is an application of the “chromatography” principle used for component separation and analysis. Even if you wondered “what’s that?”, Do you remember seeing an experiment in which ink pigments are separated with filter paper in an independent study at elementary and junior high school? Hang a strip of filter paper vertically, apply a drop of ink to a place about 3 cm from the bottom, and immerse the bottom edge of the paper in water. This experiment is called paper chromatography, and the pigment of the ink moves as the water rises due to capillarity, but it is observed that one color of ink is divided into several colors due to the difference in the degree of movement of each component.