The second golden cup theory of coffee: what is TDS? TDS reference values of countries all over the world

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As we said last time, regardless of brewing coffee with cat and dog brewing, our goal is to extract about 20% of the coffee. In order to preserve some space, we allow 18%-22% to be acceptable. To achieve this goal, of course, it has not been said that we have got the perfect coffee. But to correctly extract coffee, basically in line with this extraction rate.

Then we found that it was not easy to measure how much coffee really entered our final cup. Because we need to know how much less powder we have, and the powder is full of water after soaking, it is difficult to calculate the net weight. So we thought: if we could directly measure how much coffee we got in that cup of coffee, wouldn't everything be perfect?

Is it possible? Of course you can! Because water is basically, um, water. So there are other substances in our lovely coffee, which is probably coffee. So, if we can measure TDS (Total Dissolved Solids, total dissolved solids), we know how many strange things there are, no, coffee, in the water.

We are going to express TDS as a percentage, for example, we brew 400g of coffee. Now there is a "magic TDS measuring machine". If the TDS is 1.5%, it means it contains coffee.

The amount of coffee extracted = the coffee we brewed * TDS = 4001.5% = 6

That is, 6g of coffee! If my original coffee powder uses 30g, that means our lovely extraction rate is

Amount of coffee extracted / coffee used = 6 stroke 30 = 0.2 = 20%

Completely hit our desired extraction rate! It's so touching, really a master, you don't have to clap your hands. What is the same as what? this is a self-made figure as an example, of course, it must be as accurate as possible. Then we know that measuring TDS is a big deal, so we're going to show you how to do it next.

TDS, which measures coffee, also allows us to discuss that the "concentration" of coffee has a standard. We know that everyone's taste is different, so TDS is not in a certain range like the previous extraction rate. Each country will set the "reference value" of TDS according to its own preference, for example:

Us SCAA: 1.15%-1.35%

This is a relatively light route, and when it comes to Europe, it becomes

European SCAE: 1.25%-1.45%

Obviously Europe can accept stronger coffee, but also in Norway in Europe, it is not enough, so their standard is

Norwegian NCA: 1.3%-1.55%

Taiwan may be closer to the Norwegian standard, but you can actually prefer higher or lower concentrations, but you should pay attention to the extraction rate of 18%-22%.