How long is the appropriate soaking time for making cold extract coffee? Introduction to the parameters of grindness and gouache ratio of cold-brewed coffee

Qianjie believes that cold extracted coffee is the most suitable type of iced coffee made at home, because it has high extraction compatibility and can make good iced coffee even without professional utensils. In addition, recently, a friend asked me to teach you the grinding degree and soaking time, so I just want to talk about it today.

Although the friend did not ask the question of the proportion, the various parameters in any extraction scheme will be related accordingly, so it is necessary to mention the proportion in front of the street. Qianjie recommends that the powder-to-water ratio for cold-extracted coffee is between 1:12 and 1:13. In the front street experiment, some coffee beans with a percentage above 1:13 were lighter and tasteless. The proportion below 1:12 will appear a little thick and difficult to swallow.

Next, in front of the street, let's talk about how to choose the grinding degree and time of cold-extracted coffee. At this point, we need to talk about the extraction principle of cold-extracted coffee. Cold-extracted coffee essentially belongs to the type of soaking, which means that we can control the parameter of time (soak as long as we want, and end as long as we want).

But there is another attribute of cold extraction is low temperature extraction, that is to say, the extraction temperature is a set constant, we want cold extraction coffee to be sour or thicker, which depends on the two parameters of grinding degree and time. Compared with many other variables, cold-extracted coffee is the simplest and most friendly way of extraction. In terms of grinding fineness, it is easy to understand that the finer the coffee is ground, the faster it tastes (the faster the coffee substance is released), and the thicker the coffee powder is, the slower the coffee powder releases. But here in Qianjie, I would like to remind you that because cold-extracted coffee is a long-term static extraction, if the coffee is too fine, the coffee powder will stick together, making it more difficult for cold water to extract coffee substances. Therefore, the coffee powder is too fine to be suitable for making cold extracted coffee. Qianjie has been tested many times, and the thickness similar to the grinding degree of hand grinding (if indicated by the No. 20 screen, the screening rate is between 70-85%) can be used to make cold-extracted coffee.

Time is easier to understand. The longer you soak, the more substances the coffee releases, and the stronger the coffee will be. However, the more coffee substances are dissolved, the better. Qianjie experiments show that cold-extracted coffee is prone to the bitter taste of nuts and sawdust when it is soaked for more than 24 hours. When soaking for less than 8 hours, the release of coffee substance is not enough, which is likely to be light coffee-flavored water. Therefore, the more safe cold extraction coffee soaking time is 8-24 hours.

At this time, some friends want to ask, why this time span can be so long, 8-24 hours, the difference between 16 hours, then the flavor will not be a big difference. When we extract espresso, there may be a big difference in flavor between 1 second and 20 seconds. that is because espresso is extracted with high temperature and pressure. Hand flushing is also high temperature plus stirring force to improve the extraction efficiency. The average water temperature of cold-extracted coffee is 4-10 degrees Celsius, the extraction efficiency is very low, coupled with coffee powder and water in a relatively static state, there is no external force driven, coffee powder released flavor substances are very limited. When soaking for 8 hours, the flavor of the coffee will be bright sour and refreshing. After soaking for 16 hours, the flavor of the coffee will be more round and full, sour and sweet. After soaking for 24 hours, the flavor of the coffee will be thick, full-bodied and balanced.

If the range of grinding degree (the pass rate of No. 20 screen 70-85%) is divided into coarse, medium and fine grades. The time range (8-24 hours) is divided into short, medium and long grades. Well, in making a reasonable cold extraction coffee scheme is: the insurance practice is rough grinding with long-time extraction, which is a must for lazy people. For example, if you are free at this time today, you will most likely be free at this time tomorrow. This can save calculation time (and forget that you have been soaked in cold extraction). The time-saving method is medium and fine grinding with medium and long time, which can shorten the time accordingly, and reduce the extraction time will also make the performance of coffee more refreshing. Finally, let's talk about the cold extraction coffee making method in Qianjie. First of all, coffee beans tend to use medium-to-light roasted coffee beans in front of the street. All you need is a clean container that can be sealed. Prepare 40 grams of coffee powder, grind it into a fine grind (85% pass rate of sieve 20) into a container, then pour in 480 ml of cold water, stir with a stick and cover.

After refrigerating for 12 hours, remove the filter residue, filter out the coffee grounds and drink the coffee liquid immediately, or you can put the filtered coffee liquid into a bottle and refrigerate for another 4 hours.