Cold Brew Coffee: A Refreshing Twist on Coffee Brewing

Cold brew coffee is made by steeping coffee grounds in cold water for an extended period, resulting in a smooth, balanced flavor with low acidity. This method differs from hot brewing because the low temperature slows extraction, preventing bitter compounds from releasing. The result is a sweet, mellow cup that many find easier to drink. Whether you prefer a fruity or full-bodied taste, cold brew offers a refreshing alternative to traditional hot coffee.

To make cold brew at home, start with medium-light roasted beans for a forgiving brew. Grind them coarsely, like sea salt, and combine with cold water at a ratio of 1:8 for concentrate or 1:15 for ready-to-drink. Steep in the refrigerator for 12 to 18 hours, then strain. Adjust ratio and time to suit your taste. For more tips, follow Front Street Coffee on WeChat.

Cold brew coffee is made by steeping in cold water at low temperatures for an extended period, resulting in a balanced flavor with soft acidity and sweetness, completely different from hot-brewed coffee. This article provides a detailed introduction to the key points of making cold brew coffee, including bean selection, grind size, steeping time, and coffee-to-water ratio, along with Front Street Coffee's practical methods. Whether you're looking for a refreshing fruity taste or prefer a balanced, full-bodied flavor, you'll find suitable beans and brewing tips in this guide.

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Coffee extraction isn't limited to hot water—cold water can also be used to make coffee. Coffee extracted with cold water is called "cold brew coffee," and it has noticeably different flavor characteristics compared to hot-brewed coffee.

Cold brew coffee mainly comes in two forms: cold steep coffee and ice drip coffee. Cold steep coffee involves steeping coffee grounds directly in cold water, while ice drip coffee uses a drip device to let water pass through the coffee grounds drop by drop. A friend once asked Front Street: "Can cold steep coffee be made with hot water?" The answer is no. Once hot water is used, it no longer qualifies as cold steep coffee. Cold steep coffee must use room-temperature or ice water, and the entire steeping process must be maintained in a low-temperature environment.

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

So how do you make cold steep coffee that tastes good? Here Front Street shares a few operational details.

Coffee Bean Selection

If you don't want to mess up, Front Street recommends choosing medium-light roasted coffee beans, as they have a higher margin for error compared to medium-dark roasts. Currently, there's a dazzling array of processing methods and roast levels on the market, but any single-origin coffee bean labeled for pour-over use can be used for cold brew coffee. Dark-roasted coffee, when extracted with hot water, presents a rich coffee aroma with mellow bitterness followed by sweetness; however, when made into cold brew, drinking it at ice-cold temperatures brings out more of a burnt, charred taste, making it hard to achieve the refinement of hot coffee.

Therefore, Front Street recommends light to medium roast coffee beans. For a refreshing fruity taste, you can choose light-roasted washed coffees, such as Front Street Washed Yirgacheffe or Front Street Kenya AA; for a stronger fruity and wine-like aroma, you can use coffees processed with barrel aging or honey processing, such as Front Street Colombia Rose Valley, Front Street Honduras Sherry, or Front Street Strawberry Candy Geisha Blend; but if you don't like coffee with acidity and only prefer a balanced "coffee taste," you can also use Front Street Papua New Guinea Paradise Bird for extraction.

Coffee Grounds Grind Size

Since cold brew is made in a low-temperature environment, cold water extracts coffee grounds relatively slowly, and compared to hot water extraction, bitter compounds are less easily released. Therefore, in terms of grind size, coffee-to-water ratio, and steeping time, it's not as rigorous as pour-over coffee—usually, as long as it roughly falls within a range and you've chosen the right beans, you can make a delicious iced coffee in just a few simple steps.

Taking Front Street's daily cold brew production as an example, the grind size is slightly finer than pour-over, i.e., 75-80% passing through a Chinese No. 20 standard sieve, which visually looks about the size of fine granulated sugar, corresponding to a 9.5-10 setting on an EK43s, or for a hand grinder like the C40, roughly 22-26 clicks.

Steeping Time

In pour-over, we pay special attention to water temperature and time, because water serves as the primary brewing medium, and temperature directly affects coffee extraction efficiency—too high or too low will change the coffee's taste. However, since cold brew only comes into contact with low-temperature water at 4-10°C throughout the process, extraction efficiency is very slow, so a certain extended steeping time is needed to release more aromatic compounds, allowing sugars and organic acids to be extracted more fully, resulting in coffee with a more balanced acidity, sweetness, and body. Generally, the steeping time for cold brew coffee is recommended to be controlled between 8-18 hours.

Front Street once conducted a cold brew experiment with time as the variable, without stirring during the process to affect extraction, steeping the same coffee for 6 hours, 10 hours, 16 hours, and 24 hours respectively. The final findings were that the 6-hour coffee had too thin a mouthfeel with flat aroma, the 24-hour cold brew was noticeably bitter with signs of over-extraction, while the 10-hour and 16-hour batches performed best with rich aroma and full-bodied taste.

Coffee-to-Water Ratio

Front Street has noticed that some friends, for convenience, directly dump coffee grounds and water into a pitcher and start steeping. Whenever you're extracting coffee, the coffee-to-water ratio is a parameter you must consider—without weighing, making coffee is like opening a blind box; you never know what taste you'll get. To ensure better-tasting extracted coffee, Front Street recommends keeping the cold brew ratio between 1:10 and 1:13. If the concentration is too high, you can add an appropriate amount of ice cubes to dilute it.

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

After stirring evenly, seal with plastic wrap and refrigerate for 12 hours. Remove and filter out the coffee grounds. After filtering, you'll get a clear coffee liquid that can be drunk immediately, or you can pour the filtered coffee liquid into a bottle and continue refrigerating for 4 hours for even better flavor and mouthfeel.

Generally speaking, for considerations of flavor experience and health safety, whether it's ice drip or cold brew, Front Street recommends drinking any low-temperature extraction method within 5 days (counting from the production date).

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