How much powder does it take to make espresso? Can you drink coffee made with a difference of 0.5g of powder?

"Quantitative quantity" is an auxiliary function that most Italian bean grinders on the market are currently equipped with. The quantitative quantity of the bean grinder means that the amount of coffee powder that can be ground can be set. For example, if you set the gram weight to 20g, then this bean grinder will grind 20g of powder for you. This sounds like a very convenient feature because it eliminates the steps and time we need to weigh the powder. However, many coffee shops, including Qianjie, do not rely solely on the quantitative function of the bean grinder, but instead use electronic scales to measure the amount of coffee powder.

The reason is very simple. The quantitative quantity of most bean grinders is not so accurate. Due to many other reasons such as channels and static electricity, the final amount of coffee powder obtained will be different from the actual setting. This value will fluctuate to a certain extent due to the quality and use time of the bean grinder. For example, the Italian grinder on Qianjie will fluctuate between 0.3g and 0.5g after years of use. "Only a few tenths of a gram? Doesn't this have no impact? "Many friends raised such questions on the spot after hearing Qian Jie's explanation. It is not difficult to understand that after all, for other coffee making methods such as hand-flushing and siphoning, such a difference will not have a big impact.

However, for espresso coffee, the difference between a few tenths of a gram of powder is already huge! Even if the difference in powder amount is only 0.2g, there will be a certain difference in the extracted coffee. Why? Because coffee machines use pressure to assist extraction. Usually, coffee makers use a pressure of about 9bar to extract espresso, and for a 58mm diameter powder cake, it is equivalent to nearly 240 kilograms of force during extraction (about the weight of three adults). Such a high pressure allows the coffee substance to be quickly dissolved in a short period of time with very little water, so the espresso machine can make extremely concentrated Espresso.

However, this also makes the extraction of espresso coffee relatively more sensitive. Even if the amount of powder and grinding are only slightly changed, the extraction and taste of coffee will also differ significantly. It may not be obvious just to say it, but you can take a look at a comparison made under the front street. Combined with this comparison data, I believe that you can more intuitively feel the difference caused by the change in powder amount.

Qianjie used 19.5 g, 20g, and 20.5 g of powder to extract two cups of concentration respectively. The weight of each cup of concentration was the same as 38ml. Then the average concentration time and extraction rate of each group were measured respectively, and finally the following results were obtained:

Amount of powder used Extraction time Extraction rate 19.5g 27s 22.37% 20.0g29s 21.70% 20.5g33s 21.42%

It can be seen that the extraction time is gradually increasing with the increase of the amount of powder. This is because the amount of powder determines the thickness of the powder cake. When the amount of powder is more, the more time it takes for hot water to pass through the powder cake, and vice versa; and the extraction rate is gradually decreasing with the amount of powder. This is because the change in the amount of powder and the fixed amount of liquid lead to a change in the proportion, so the extraction rate of coffee will change accordingly.

By tasting, we can intuitively tell the difference between the three. There is not much change in flavor, because it uses warm sun combinations, so the flavors are all whisky aroma, butter cookies, and a little berry flavor. The most intuitive change comes from the taste and taste. The first cup of concentrated (19.5 powder extract) tastes relatively thin, but the finish has obvious bitterness; the second cup of concentrated (20 powder extract) tastes moderate, has balanced taste and high sweetness; and the third cup of concentrated (20.5 powder extract) tastes the thickest among the three cups, but its taste performance is lacking and there is not much finish.

The reason for the difference in taste and taste is that the different amount of powder changes the concentration and extraction rate. The reason why the middle cup is the best is because it is the best parameter adjusted in the morning today! So everyone can know that even a few tenths of a gram of powder can have a significant impact on the extraction of espresso. When the gap in fan quantity becomes wider, the greater the impact will be. If you make it at home to satisfy your appetite, of course you can do whatever you want. You don't have to be too picky. After all, you are drinking it for yourself. But if you want to produce it for customers in a store, it's best to pay a little attention to details and be more rigorous. Although the guests don't know whether your parameters are correct or not, they can still judge whether it tastes good or not ~

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