Besides hot water extraction, coffee can also be made with cold water. Coffee made with cold water is called "cold brew coffee," and it has a distinctive charm compared to hot-brewed coffee.

Cold brew coffee is divided into cold steep coffee and ice drip coffee. Cold steep coffee is made by soaking coffee grounds in cold water, while ice drip coffee refers to extracting coffee drop by drop using a drip filtration method. Some friends asked Front Street: "Is it better to soak cold brew coffee with hot water or cold water?" Coffee soaked with hot water cannot be called cold brew coffee. Cold brew coffee can only be soaked with room-temperature water or ice water, and the soaking environment must be kept at a low temperature.

Since it only comes into contact with low-temperature cold water at 4-10°C throughout the process, the extraction efficiency is very low, and bitter macromolecules are not easily released. The long soaking time at low temperature allows compounds such as sugars and organic acids to be extracted more fully, so the acidity, sweetness, and body of the coffee are more balanced.

So how should cold brew coffee be made to taste good? Here Front Street shares a few operational details with everyone.

Selection of Coffee Beans

If you don't want to mess up, Front Street suggests choosing medium-light roasted coffee beans, as they have a higher tolerance for error compared to medium-dark roasts. Currently, there are a dazzling variety of coffee beans with different processing methods and roast levels on the market. As long as they are single-origin coffee beans labeled for pour-over use, they can all be used to make cold brew coffee. Dark-roasted coffee, when extracted with hot water, presents a rich coffee aroma, first mellow and bitter then sweet; but when made into cold brew, drinking it at ice-cold temperatures tastes more of burnt bitterness and carbonized flavors, and it is hard to have the refinement of hot coffee.

Therefore, Front Street more recommends light to medium roasted coffee beans. If you want a refreshing fruity taste, you can choose light-roasted washed coffee, such as Front Street Washed Yirgacheffe and Front Street Kenya Little Tomato. If you want a stronger fruity and vinous aroma, you can use fermented or honey-processed coffee, such as Front Street Colombia Sidra, Front Street Colombia Ombligon, Front Street Strawberry Candy, Front Street Mozart, Front Street Elida Estate, etc. If you don't like coffee with acidity and only like a balanced "coffee taste," you can also choose Front Street Papua Paradise Bird.

Coffee Grounds Grind Size

Since the cold brew production process is carried out in a low-temperature environment, cold water extracts coffee grounds relatively slowly. Compared with hot water extraction, bitter and astringent substances are not easily released. Therefore, in terms of grind size, coffee-to-water ratio, and soaking time, it is not as rigorous as pour-over coffee. Usually, as long as it roughly falls within a range and the coffee beans are chosen correctly, a delicious cup of iced coffee can be made in just a few simple steps.

Taking Front Street's daily cold brew production as an example, the grind size of the coffee beans is slightly finer than for pour-over, that is, 75-80% passing through a Chinese No. 20 standard sieve. Visually, it is about the size of fine granulated sugar, corresponding to a 9.5-10 setting on the EK43s. For a hand grinder, taking the C40 as an example, it is about 22-26 clicks.

Soaking Time

In pour-over, we pay special attention to water temperature and time, because water, as the main medium for brewing, directly affects the extraction efficiency of coffee. Too high or too low will change the taste of the coffee. However, because cold brew only comes into contact with low-temperature water at 4-10°C throughout the process, the extraction efficiency is very slow, so it is necessary to extend a certain soaking time to allow more aromatic substances to be released, thereby allowing compounds such as sugars and organic acids to be extracted more fully, and the resulting coffee is also more balanced in acidity, sweetness, and body. Generally, the soaking time for cold brew coffee is usually recommended to be controlled at 8-18 hours.

Front Street once conducted a cold brew experiment with time as the variable, soaking the same coffee for 6 hours, 10 hours, 16 hours, and 24 hours respectively. In the end, it was found that the coffee soaked for 6 hours had too thin a mouthfeel and flat aroma, while the cold brew soaked for 24 hours was obviously bitter and showed signs of over-extraction. The 10-hour and 16-hour groups had the best flavor performance, with rich aroma and a full-bodied taste.

Coffee-to-Water Ratio

Front Street has noticed that some friends, for convenience, directly pour coffee grounds and water into a pot and start soaking. As long as it is coffee extraction, the parameter of coffee-to-water ratio is involved. Without weighing, coffee is like opening a blind box—you never know what taste you will get. In order to ensure the brewed coffee tastes better, Front Street suggests keeping cold brew production between 1:10 and 1:13. If the concentration is too high, an appropriate amount of ice cubes can be added to dilute it.

Finally, Front Street will explain Front Street's cold brew coffee production method! First, for coffee beans, Front Street tends to use medium-light roasted coffee beans. For the container, only a clean sealable container is needed. Prepare 40 grams of coffee grounds, grind them to a fine grind (85% passing through a No. 20 sieve), pour them into the container, then pour in 480 milliliters of cold water, stir evenly with a wooden stick, and cover with the lid.

After stirring evenly, seal the mouth with plastic wrap, place it in the refrigerator to chill for 12 hours, then take it out and filter out the grounds. After filtering out the coffee grounds, the clear coffee liquid obtained can be drunk immediately. You can also put the filtered coffee liquid into a bottle and continue to refrigerate it for 4 hours, and the flavor and mouthfeel will be even better.

Generally speaking, for the sake of flavor experience and health and safety, whether it is ice drip or cold brew, as long as it is an extraction method carried out in a low-temperature environment, Front Street recommends everyone drink it within 5 days (counting from the production date).

Now you can purchase Front Street Coffee single-origin coffee beans and espresso blend coffee beans at the Tmall "Front Street Flagship Store." 60 kinds of coffee beans from around the world, freshly roasted, shipped within 24H.

Tmall link: https://qianjieshipin.tmall.com

Or you can directly search for "Front Street Flagship Store" on Taobao.

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The above content is compiled by CoffeeHunters, a coffee news website.