Cold-brew coffee FAQs
What is cold brew?
Cold brew is coffee brewed cold or at room temperature, instead of with hot water.
Rinaldi said making a batch of cold brew can take 12 to 24 hours, depending on your recipe. That is, of course, significantly slower than any hot water method. But in the absence of heat, it takes much longer for all of those delicious organic compounds and oils to become fully extracted from the ground coffee.
This process slightly changes the flavor too. Helfen said, “Oftentimes, the nuance of the coffee is lost in cold brew, but because the sugars in coffee take longer to extract, the extra brew time can increase sweetness.” According to Rinaldi, some of the more volatile organic compounds aren’t extracted as readily so cold brew can produce a really clean and less acidic flavor profile.
Why should I buy a cold brew maker?
Cold brew is easy to make in any jar or jug, but having a specialized cold brew maker certainly makes the process easier. All of the brewers I tested are designed to make the brewing process cleaner and faster. Most importantly, they all provide a dedicated mode of filtration that is geared toward brewing a more clear and refreshing cup of coffee.
What’s the difference between cold-brew concentrate and cold brew that’s ready-to-drink?
Cold-brew makers can produce cold-brew concentrate or cold brew that is ready to drink. The concentrate is usually a much stronger extraction with higher caffeine content and must be diluted at a coffee to water ratio of 1:3 or 1:2.
Ready-to-drink cold brew doesn’t require any dilution and can be consumed right away. It’s usually lighter in color, and the strength and flavor are more reminiscent of tea. It’s a more bright and refreshing drink, whereas concentrate offers a more full-flavored, dark, intense product. Most cold-brew devices are advertised as producing either concentrate or ready-to-drink, but some are flexible enough to do both. In those instances, you can increase the strength of the coffee and create a concentrate by using less water and steeping for longer.
What are the differences between automatic, immersion, and drip cold brew?
There are a few ways cold-brew makers work. Each method has its pros and cons, but immersion brewing is the standard style, and the most common, accessible, and affordable. Here, the grounds are submerged in room-temperature water for an extended period of time. The ground coffee can be contained in a filter basket, a paper filter, or hang loose in the water and be filtered later.
Drip cold brew, also known as the Kyoto Method, is made by slowly dripping cold water over a bed of ground coffee, which is then filtered. Like immersion brewing, this process can take 12 or more hours. These brewers tend to be a bit more complex and expensive, and aren’t as common as immersion or automatic makers.
Automatic cold-brew makers are a newer entry in the market that use different methods to speed up the brewing process. For example, the Cuisinart Automatic uses a motor to spin the filter basket around in the water tank, agitating the grounds and creating a batch of cold brew in 25 to 45 minutes.
What is the best kind of coffee to use for cold brew?
There is no “correct” coffee when it comes to cold brew — feel free to use any coffee you like. I used blends for my tests, but single-origin roasts are also commonly used. Rinaldi said, “Darker roasted coffee is more extractable, so you see a lot of espresso roasts being prepared as a cold brew.” I’ve also seen many cafes rotating single-origin blends to provide a variety and different choices to their customers. Ultimately, like many aspects of home brewing coffee, it all comes down to personal taste.
What’s the best grind coarseness for cold brew?
Coarse grind size — similar to what you’d use for a French press — is usually recommended for cold brew, and what I used in testing.
The major factor to consider with the grind size is filtration. A finer grind can turn muddy over a long brew time, making it more difficult for the water to pass through the grounds during filtration. Helfen said, “Most folks grind coarser for cold brew because of the long brew time and because filtering the liquid out of the grounds doesn’t take as long.”
Paper and felt filters tend to filter out more of the fine solids than metal or mesh filters, and a finer grind will pass through more than a coarse one. Too much sediment makes a silty, cloudy cup of coffee, which is not desirable with cold brew. Of course, there are exceptions. Some brewers I tested, like the Cuisinart Automatic, respond well to a finer grind because of the shorter extraction time needed.
What is the proper ratio of coffee to water for cold brew?
The ratio of coffee to water will vary slightly depending on whether you’re brewing concentrate or ready-to-drink cold brew, and which coffee maker you use. The ratios we recommend are 1 part coffee to 5 parts water, or a 1:5 ratio, for concentrate and 1:7 for something that’s ready to drink. I recommend following the instructions included in your brewer and adjusting the ratio to taste. The one thing that’s consistent across all brewers is that cold brew uses way more ground coffee than traditional brewing, so be prepared with your beans.
Should I steep my cold brew in the refrigerator or at room temperature?
From all of my testing, I found that letting the coffee steep at room temperature produces a much better flavor than leaving it in the fridge for an extended period of time. But Helfen does add one caveat. “I find brewing at room temp quite risky. Unless you’re very meticulously sanitizing your brewing equipment, the bacterial growth of coffee brewing at room temp can get out of control pretty easy.” If this is a concern, most cold brew devices are dishwasher safe or have removable components that can be cleaned in a dishwasher.
How long does cold brew stay fresh?
Unlike hot coffee, which maintains freshness for no longer than a few minutes, cold brew can maintain its flavor in the fridge for a while. If stored in an airtight container in your refrigerator, it should stay fresh for up to two weeks.