Cold brew coffee is the most suitable type of iced coffee to make at home, because it has a high degree of extraction compatibility, and even without professional equipment, you can make good iced coffee. Many people ask the question of grinding degree and soaking time, so today I just want to talk about it.
Cold Brew Concentrate Ratio
Although this friend did not ask about the ratio, the various parameters in any extraction scheme will be related accordingly, so it is necessary to mention the ratio. The recommended ratio of powder to water for making cold brew coffee is between 1:12 and 1:13. In the experiment, some coffee beans with a ratio higher than 1:13 will be relatively weak and taste flat. A ratio below 1:12 will appear a bit thick and hard to swallow.
Cold Brew Grind Size
Next, let’s talk about how to choose the grinding degree and time of cold brew coffee. At this time, we need to talk about the extraction principle of cold brew coffee. Cold brew coffee is essentially a steeping type, which means that we can control the parameter of time (brew as long as you want, and end when you want).
However, another attribute of cold extraction is low-temperature extraction, that is to say, the extraction temperature is a set constant. If we want cold-extracted coffee to be more sour or thicker, it depends on the two parameters of grinding degree and time. decided. Compared with many other variables, cold brew coffee is the easiest and most friendly way to brew.
In terms of grinding thickness, we can easily understand that the finer the coffee is ground, the faster the flavor will be released (the coffee substance will be released faster), and the coarser the grind, the slower the coffee powder will release the substance. But here is a reminder, because cold-brew coffee is a long-term static extraction, if the coffee is too fine, the coffee powder will "cluster" and stick together, so that it is more difficult for cold water to extract the coffee substance. Therefore, coffee powder that is too fine is not suitable for making cold brew coffee. After many tests, it is found that the thickness similar to that of manual pouring (if it is represented by a No. 20 sieve, the sieving rate is between 70-85%) can be used to make cold brew coffee.
Bold Brew Time
And time is better understood, the longer the brewing time, the more substances the coffee will release, and the stronger the coffee will be. However, the more dissolved the coffee substance is, the better it is. Experiments show that cold brewed coffee tends to have a nutty, sawdust-like bitter taste when soaked for more than 24 hours. However, if soaked for less than 8 hours, the release of coffee substances is not enough, and it is most likely to be weak coffee-flavored water. Therefore, the safer cold brew coffee steeping time is 8-24 hours.
At this time, some friends want to ask, why the time span can be so long, 8-24 hours, with a difference of 16 hours in between, so the flavor will not vary greatly. When we extract espresso, the difference of 1 second may be very different in flavor. When pouring by hand, the difference of 20 seconds can distinguish the change of flavor. That is because espresso is extracted by high temperature and pressure. Punching is also a high temperature plus stirring force to improve the extraction efficiency. The average water temperature of cold brew coffee is 4-10 degrees Celsius, and the extraction efficiency is very low. In addition, the coffee powder and water are in a relatively static state. Without external force, the flavor substances released by the coffee powder are very limited.
When steeped for 8 hours, the flavor of the coffee will be acidic bright and refreshing.
After steeping for 16 hours, the flavor of the coffee will be more round and full, full of sweet and sour.
When soaked for 24 hours, the flavor of the coffee will be thicker, full-bodied, and balanced.
If the range of grinding degree (passing rate of No. 20 sieve is 70-85%) is divided into three grades of coarse, medium and fine. The time range (8-24 hours) is divided into three levels: short, medium and long. Then the reasonable cold brew coffee plan is as follows:
The insurance method is coarse grinding combined with long-term extraction, which is a must for lazy people. For example, if you are free at this time today, there is a high probability that you will be free at this time tomorrow, which can save calculation time (and forget that you have soaked cold brew thing).
The way to save time is to mix medium and fine grinding with medium and long time, which can shorten the time accordingly, and reducing the extraction time will also make the coffee more refreshing.
Finally, how to make cold brew coffee!
First of all, the coffee beans tend to use medium and light roasted coffee beans. Only a clean, airtight container is required on the container. Prepare 40 grams of coffee powder, grind it into a fine grind (No. 20 sieve pass rate of 85%), pour it into a container, then pour 480 ml of cold water, stir it evenly with a wooden stick, and cover it.
Put it in the refrigerator for 12 hours, take out the filter residue, and drink the coffee liquid after filtering out the coffee grounds. You can also put the filtered coffee liquid in a bottle and continue to refrigerate for 4 hours, the flavor and taste will be better.