How to make cold coffee with espresso coffee? How to brew cold extract coffee? How long can cold brewed coffee last?

Cold extracted coffee, simply understood, is coffee extracted with cold water. Because it is very simple to make and has excellent flavor and taste performance, cold extract coffee has always been a must-have for most friends at home. But cold extract coffee is not without shortcomings. For example, the time it takes to make is too long, which is the biggest flaw that prevents it from "dominating" coffee makers around the world! (exaggerated)

The time it takes to make a bottle of cold extract in the traditional way basically starts in 8 hours. It is not just the soaking time, but the cold extract is also like ice drops. It still takes a certain amount of time to "mature" to develop a complete flavor. Unless there is already pre-made cold extract in the refrigerator, when you want to drink a cup of cold extract coffee, you will have to wait for most of the day for on-site production (except for ordering takeout). So many impatient friends have to ask: "Is there any way to shorten the making time of cold extract coffee? "

Of course there is! The reason why the production of cold extract coffee takes a long time is that the water temperature used for extraction is too low, and the kinetic energy of water molecules is weak, so it cannot quickly dissolve the flavor substances in the coffee like high-temperature water. So as long as we slightly increase the initial water temperature during soaking, we can improve the water extraction efficiency and shorten the extraction time. This is a method that Qianjie just shared some time ago.

But many friends are not satisfied with this, because now we can often read posts in a book: "It only takes a minute to make a sweet and cold extract." Due to the short time and the large number of bloggers sharing it, friends often ask Qianjie in the store what method can be used to make high-sweet and cold extracts in such a short period of time. First of all, we need to know that factors that can affect extraction efficiency are not only time and water temperature, but also grinding, water volume, and extraction method! As mentioned earlier,"making high-sweet cold extraction in one minute" is the result achieved by changing the extraction method.

The specific method is very simple, which is to use hand-pressed or an espresso machine that can be extracted with cold water. In this way, just like making espresso coffee, the flavor substances in the coffee can be quickly dissolved by cold water with a pressure of up to 9bar. Qianjie conducted a related experiment last year, adding ice water to a hand-pressed coffee machine to extract coffee. As a result, as Qian Jie expected, I got a cup of cold extract coffee that looked good in just a few minutes.

However, it just looks good! It tastes like a cup of coffee-flavored water. In addition to the water temperature used meeting the requirements of cold extracted coffee, the taste, taste and concentration are completely inferior to cold extracted coffee obtained by soaking for a long time. You want to say it is sweet... It's really sweet, because the taste is hardly extracted, so it tastes slightly sweet, a bit similar to the taste of apples. Qianjie has also tried to use a finer grind than extracting espresso coffee, more water (hot extraction 1:2 powder-to-liquid ratio, cold extraction 1:10 powder-to-liquid ratio), and longer time (hot extraction 30 seconds, cold extraction 3 minutes) to increase extraction efficiency. But even so, the coffee machine still cannot use cold water to extract a cup of strong coffee. The reason is that the water temperature is too low!

Not only is the kinetic energy of cold water not enough, but also because cold water cannot soften the fiber of coffee in a short period of time like hot water, and its concentration saturation point is also low. This is why even with the help of pressure, coffee machines cannot dissolve the flavor substances in coffee quickly and in large quantities. This is why cold extracted coffee requires time compensation to obtain a relatively complete flavor.

To sum up, everyone can know that although this method can indeed make a cup of "cold extract coffee" in a short period of time, the cold extract produced in this way is only empty, whether it is taste or taste, and the cold extract we know is completely different. If you want to shorten the cold extraction and soaking time, you may wish to slightly increase the water temperature of the initial soaking as mentioned at the beginning of Qianjie. This will not only shorten the extraction time, but also allow the flavor substances to dissolve more completely ~

But then again, since you've already used a coffee maker, why not just extract a cup of espresso and add ice to make iced coffee? Isn't it more convenient?

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