How do you make cold brew coffee from ground coffee?

Cold brew is coffee extracted with cold water rather than hot. Grind coffee beans into powder, steep them in cold water for at least 12 hours, then extract and filter through a dedicated device. Extending the steep to 24 or 48 hours builds a more pronounced body. The method needs almost no technique: a bottle, a bag of beans and one night.

Because extraction happens at low temperature, acidic compounds decrease over the steeping time and aromas volatilize less, so the cup tastes less sour and astringent, smoother and better balanced than hot brew. Iced coffee differs: it is first extracted hot, then cooled with ice when served. After filtering, storage matters, and keeping the concentrate sealed and cold preserves flavor.

On a scorching summer day, a refreshing glass of cold brew coffee always perks you up. Compared with pour-over, cold brew has a much lower barrier to entry—you only need to master a few key parameters like the coffee-to-water ratio, grind size, and steeping time, and you can easily make a rich, smooth iced coffee at home. In this article, Front Street will walk you through the complete cold brew process in detail, including how to choose the coffee-to-water ratio, how to control grind size, the relationship between water temperature and extraction time, and storage tips after filtering. We'll also analyze the flavor differences between cold brew and hot brew to help you understand why cold brew tastes less sour and astringent and feels smoother. Whether you're a beginner just getting into cold brew or a seasoned hand looking to fine-tune your parameters, you'll find practical references here.

Once summer arrives, all kinds of trendy iced coffees start appearing frequently in everyone's feed. On a muggy day, a glass of iced coffee really does cool you down instantly. Today, the star Front Street wants to talk about is cold brew coffee. This coffee is hugely popular among office workers—why is that? Front Street thinks the key reason cold brew is so well-loved is its very low barrier to entry; compared with pour-over coffee, it's simply far too easy.

Next, Front Street will go into detail about cold brew coffee.

As the name suggests, cold brew coffee is coffee extracted at lower temperatures, written as Cold Brew Coffee in English. Many people confuse it with iced coffee, but iced coffee usually refers to coffee that is first extracted with hot water and then cooled with ice when served. So the most fundamental difference between the two lies in the extraction temperature. So how exactly is cold brew defined? Simply put, it means grinding coffee beans into powder, steeping them in cold water for at least 12 hours, and then extracting and filtering through a dedicated device. If you want a more pronounced body, you can extend the steeping time to 24 to 48 hours.

Front Street believes that although cold brew has a longer production cycle, it requires virtually no technique—a bottle, a bag of beans, one night, and the next morning you can drink a full-bodied, rich iced coffee. This is also why many people love cold brew. The principle behind cold brew is actually quite simple: the core is to get the coffee-to-water ratio right, then rely on a long steeping time (over 12 hours) to ultimately get a refreshing, ice-cold coffee. Grind and brew it at home the night before, put it in the fridge to chill overnight, and when you wake up the next day you can drink cold coffee—that feeling is truly delightful.

Cold brew and pour-over follow two different paths in terms of extraction method. Cold brew uses low-temperature extraction, so far fewer bitter compounds are released, and the process is simpler. Front Street thinks that as long as you control the coffee-to-water ratio well, anyone can make a delicious cold brew.

Front Street's method for making cold brew coffee

As Front Street mentioned earlier, cold brew isn't complicated to make, especially when compared side by side with pour-over—the steps are more intuitive and straightforward. As long as the parameters are set properly, you can easily make a tasty iced coffee. So when making cold brew, how should you determine parameters like grind size and coffee-to-water ratio?

Front Street generally recommends a coffee-to-water ratio of 1:12 for cold brew, using 50 grams of coffee grounds as the baseline. Cold brew made at this ratio has just the right concentration and can be drunk directly without dilution. Of course, some people like to add milk, soda water, or use it for fancy coffee drinks, in which case you need to make the coffee stronger. Front Street suggests that if the cold brew is intended for specialty drinks, the coffee-to-water ratio can be adjusted to 1:10.

Grind size for cold brew coffee

The grind size of coffee is closely related to the brewing method. Cold brew uses ice water for steeping extraction, and the extraction efficiency itself is very low—in other words, you hardly need to worry about over-extraction. When Front Street makes cold brew, the grind is slightly finer than for pour-over, with a reference standard of 85% passing through a No. 20 standard sieve, keeping the proportion of fines as controlled as possible. But Front Street also wants to remind you: although low-temperature extraction can reduce the release of bitter compounds, it doesn't mean they won't appear at all. If you grind too fine, after the sour and sweet compounds in the coffee grounds are quickly extracted, the body-giving compounds will be released next. A moderate amount of body-giving compounds can enhance the coffee's body, but if the steeping time is too long, woody flavors will emerge and the cleanliness of the whole cup will decline.

Coffee-to-water ratio

Some friends may ask: how much water should be used for steeping? Front Street's standard approach is a ratio of coffee, water, and ice of 1:8:4, which works out to an actual coffee-to-water ratio of 1:12. The purpose of adding ice is to ensure the water temperature is low enough to keep extraction efficiency at a stable level.

Temperature

Front Street has previously explained that the water temperature for pour-over coffee is related to the roast level, but cold brew has no strict temperature requirements—just put it in the fridge for low-temperature extraction. With low-temperature extraction, the steeping time needs to reach 24 hours. So can cold brew be extracted at room temperature? Of course it can, but you'll need to shorten the extraction time accordingly. Front Street Coffee (FrontStreet Coffee) recommends keeping the time between 8 and 12 hours for room-temperature extraction.

Front Street Coffee (FrontStreet Coffee) uses 50 grams of coffee grounds as the baseline when making cold brew. After grinding the coffee beans, put them into a clean, oil-free sealed container, pour in 400 ml of room-temperature water, then add 200 grams of hard ice cubes (ice-water mixture totaling 600 grams), close the lid tightly and shake gently to ensure the coffee grounds fully contact the ice water, then place it in the fridge and let it sit for 12 to 24 hours. After extraction is complete, filter out the coffee grounds with filter paper or a fine mesh strainer, then pour the coffee liquid into a clean sealed bottle and refrigerate for about 4 hours before drinking.

How long can cold brew coffee be stored after filtering?

Front Street has previously discussed how to drink pour-over coffee—different temperatures give different flavors—but pour-over shouldn't be kept for long; even if it's only been a day, you should finish it as soon as possible. Cold brew is different. Theoretically, the longer cold brew sits, the more pronounced the fermented flavor becomes. But over-fermentation will make the coffee lose its original flavors. If you don't particularly like a heavy fermented taste, Front Street doesn't recommend trying it casually. The best time to drink cold brew is within 2 to 3 days after filtering out the grounds, and storage time should preferably not exceed 7 days.

Low temperature and long extraction time are the two notable characteristics of cold brew, and also its most core differences from hot brew coffee. Hot brew coffee uses water at 88 to 91°C to extract coffee grounds, usually for no more than 5 minutes. The fastest espresso takes only 18 to 23 seconds, while cold brew far exceeds all these hot brew methods in terms of time. Speaking of cold brew's long extraction time, Front Street would like to sum it up with a rather poetic line—"What you're drinking isn't just a cup of coffee, but a long wait."

Characteristics of cold brew coffee

From a flavor perspective, high temperatures cause the tannic acid in coffee to break down into pyrogallic acid, bringing sourness and astringency. Research shows that cold brew coffee contains 67% less acidic substances than hot brew methods. Therefore, compared with hot brew coffee and iced coffee made by adding ice to hot brew, coffee made by the cold brew process is less sour and astringent, which is also why it's so popular. If you don't particularly like coffee with prominent acidity, cold brew is a good choice.

In addition, Front Street found that the low-temperature environment combined with long contact with coffee grounds means only small-molecule flavor compounds can be extracted, such as floral and fruity notes; while flavor compounds with larger molecular weights, like smoky and roasted notes, are hard to extract. This explains why cold brew coffee doesn't have that intense aromatic impact when you smell it, but tastes smoother, richer, with clear layers, noticeable sweetness in the finish, and no greasy feeling.

Of course, all of the above must be built on the premise that the coffee beans are fresh enough. Front Street Coffee (FrontStreet Coffee) knows well that the freshness of coffee beans has an enormous impact on flavor. Front Street's roasting philosophy is "Freshly roasted good coffee," striving to ensure every customer who places an order receives the freshest beans when their coffee arrives. So the coffee beans shipped by Front Street Coffee (FrontStreet Coffee) are all within 5 days of roasting, and coffee's resting period is about 4 to 7 days, so by the time customers receive them, they're right at their peak flavor.

Front Street believes that any coffee-making method requires repeated practice to better bring out the full flavors of the coffee. Front Street has half a hundred coffee beans from different producing regions, allowing everyone to taste a more comprehensive range of coffee flavors; friends can also come to Front Street Coffee (FrontStreet Coffee) and chat about coffee with our baristas.

For professional coffee knowledge exchange and more coffee bean information, please follow Coffee Workshop (WeChat public account: cafe_style)

For more specialty coffee beans, please add the private WeChat of Front Street Coffee (FrontStreet Coffee), WeChat ID: qjcoffeex

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