What is the effect of water quality on coffee extraction? a brief Analysis of the effect of Hot Water quantity on Coffee extraction

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Front Street Coffee-Share the impact of water temperature and water volume on coffee extraction

Water quality, including total hardness, alkali hardness, pH value, water and other major factors. Coffee extraction generally refers to "water quality", mostly refers to "total hardness". This article will explain the relevant words in as simple a statement as possible and summarize a set of minimalist but scientific logical methods to understand the impact of water hardness on coffee.

1. Extraction ≠ dissolution

The essence of extraction refers to the ions in A substance, and the ions of B are replaced from B substance into A. Coffee circles often say "extraction" for a long time, only refers to the physical "dissolution", did not consider the chemical "extraction" concept. That is, only saturation is considered.

2. Saturation

The maximum amount of a water-soluble substance dissolved in water at a specified temperature, usually by weight.

The saturation of any water-soluble substance is not constant and will vary with temperature and pressure, such as concentration.

Assuming that the same bean is perfectly extracted in both concentration and drip filtration, the extremely high concentration of concentration depends on the much higher saturation of its water-soluble substances compared to drip filtration, because of the high pressure in the handle; while when the concentrated liquid enters the cup at atmospheric pressure, some of the supersaturated substances will precipitate crystals, and some will not have time to crystallize, so it will appear different from drip filtration heavy feeling, grainy feeling, silky feeling or other tactile sensation.

Total hardness of water

It refers to the total concentration of calcium, magnesium, carbonate, chloride and other salts in water. After heating, carbonate decomposes and precipitates, which is no longer included in the total hardness.

Coffee ring commonly used water hardness measurement unit with the United States, that is, ppm, refers to each liter of water contains 1 mg of calcium carbonate is 1ppm.

Generally, the hardness of coffee water is 100-140ppm, slightly higher or lower, depending on the coffee itself and the brewing scheme, there is no standard hardness value.

4, the total hardness of the extraction capacity

Theoretically, the harder the water, the more powerful the extraction, the easier it is to extract coffee-not the harder it is. Why?

Because first of all, here only discuss hardness, that is, calcium ions, magnesium ions, chloride, etc. in water, do not discuss "saturation";

Secondly, the chemical properties of extraction are "replacement", the higher the hardness of water, the more ions it contains, the stronger the replacement ability, so the stronger the extraction ability, so the easier it is to extract coffee. For example, under the same conditions, 100ppm water extraction coffee, than 0ppm extraction yield is higher.

If the water temperature of the extracted coffee is too high, more flavor substances will be extracted in advance, which will eventually lead to too many extracted substances in the coffee; the amount of water extracted will also affect the overall flavor and taste of the coffee.

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