The ratio of water to powder refers to the ratio of coffee powder to water injection.

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Author: uncle Dewa

Link: http://www.zhihu.com/question/22664244/answer/42860980

Source: Zhihu

First of all, let's talk about a little bit of personal opinion, this parameter is best called powder-water ratio. Because it is generally presented in the way of [1:xx], that is, the ratio of one part of coffee powder to how many parts of water, it is called the ratio of powder to water is more strict.

Let's answer the landlord's question: does the ratio of water to powder refer to the ratio of coffee powder to water injection, or the ratio of coffee powder to production?

First of all, the quantification of the powder-to-water ratio is widely accepted because of the coffee product management table (The Brewing Control Chart) issued by the SCAA (American Fine Coffee Association), which is shown below:

(the picture is quoted from the Internet, and the copyright belongs to the original issuer)

The Brewing Ratio in the upper left corner is what we call the powder-water ratio. Obviously, it refers to the ratio of coffee powder to the amount of water, which refers to the amount of unboiled water that has not yet been boiled.

Let's take a look at its unit: Grams / 1.9Liter, which is mass: volume, not just mass: mass. Maybe many friends don't have measuring cups at home, but don't worry, we can use [quality of coffee powder: quality of water] to calculate the ratio of water to powder. Briefly explain why friends who don't want to be serious can choose to skip:

If you measure unboiled water. High school physics taught us that the density of water at room temperature is equal to 1 (or about 1). Therefore, at room temperature, the mass of 1 mL raw water can be regarded as equal to 1 g (1 g raw water = 1 mL raw water).

If you measure hot water directly, it is more appropriate to use mass units to measure it. Because the density of hot water is lower than that of raw water, the mass of hot water with a volume of 1 mL is less than 1 g. Hot water measured in units of mass is equivalent to the same volume of raw water (1 g hot water = 1 mL raw water, too).

For example, suppose you have 10 grams of coffee powder and use the 1:10 ratio of powder to water to brew. If you use a cup to measure 100 mL of hot water, its mass may be only 97 g, which is 3 g (mL) shorter than 100 mL of raw water. As a result, your powder / water ratio becomes 1 mL 9.7. Using an electronic scale to measure 100g of hot water, although its volume may have expanded to 104mL at that time, it will return to 100mL at room temperature, which is exactly the amount we need.

As for the second part of the main question: siphon, hand punch and legal pressure, what is your favorite gouache ratio?

In fact, everyone's tastes are different, and there is no absolute powder-to-water ratio, so the respondent will not impose his personal preferences on everyone.

It can also be seen from the SCAA coffee product management table given above. Different red slashes in the table represent different powder-to-water ratios, and even in the middle of the small golden matrix region, there are five different red lines passing through.

For you, by adjusting the powder-to-water ratio that best suits your taste, is the best powder-to-water ratio.