If you, like many people across the country, love cold brew, you're probably wondering how to make your preferred java last a little longer in the refrigerator. Whether you're making it yourself or buying it in the store, have you ever stopped to consider if you're storing your cold brew properly? What's more, do you know how long can you keep cold brew coffee in the refrigerator for? Here, coffee experts share how to ensure your cold brew stays fresher longer, remains food-safe, and tastes good.
What Is Cold Brew?
First, let's differentiate cold brew from your standard brewed coffee. According to Travis Beckett, the Seattle regional educator for Counter Culture Coffee, "regular coffee" (i.e. filter drip, espresso, or a pour over) is typically brewed using hot water that's between 195 and 205 degrees Fahrenheit. This can be poured over ice for those who prefer iced coffee drinks. Whether served hot or cold, this type of coffee is "aromatic" and "bright," notes Beckett.
Cold brew, as the name suggests, uses cooler water (usually either refrigerator temperature around 38 degrees Fahrenheit or ambient temperature around 70 degrees Fahrenheit) during the brewing process, says Beckett. Because the water is cooler, it takes a longer time to brew. For example, making cold brew in the refrigerator can take 18 hours, but brewing on the countertop may only require 12 hours (hot coffee, on the other hand, takes just a few minutes to brew). So, what's the benefit to waiting this long for a cup of coffee? Beckett says the combination of a longer brewing time and cooler water creates a coffee that has a fuller body, smoother texture, and delicate aromas.
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Cold Brew Versus Cold Brew Concentrate
In addition to the standard ready-to-drink cold brew, you can also make a cold brew concentrate. While "ready-to-drink cold brew uses the right amount of coffee from the beginning to give you the desired strength and flavors" (so no dilution is needed), concentrate is made by "using more coffee grounds or less water, and needs to be diluted with cold water after filtering out the grounds," says Beckett. If you order cold brew from a coffee shop, they are often using a concentrate, which saves space and is more efficient when serving a crowd. Beckett says for the at-home coffee maker, making a concentrate is usually unnecessary. He recommends "that coffee enthusiasts make their cold brew at home using a ready-to-drink strength recipe." He personally brews his cold brew in the refrigerator for 18 hours, and then pours it over ice.
Storing Cold Brew
If you're making cold brew in bulk, you want to make sure you're storing it properly. Beckett recommends storing your cold brew (and/or concentrate) in a closed-top container (sealed glass or plastic) in the refrigerator (room temperature storage is more prone to bacterial growth). You'll want to drink your cold brew within a few days; any longer, and you risk the brew oxidizing, which will make it taste stale. According to Chi Sum, co-founder of Coffee Project NY, "since every person's recipe and choice of beans (roast level, grind size, etc.) is different, it contributes to how long the coffee can be stored before tasting stale, flat, and [undergoes] a possible change of acidity." She's seen anywhere between two days to seven days.
Selina Viguera, Blue Bottle Coffee Abbot Kinney cafe leader, says they keep their cold brew concentrates for up to two weeks, but once it has been diluted, they try to serve it within three or four days. "Fresher is always better when it comes to drinking your cold brew, and making smaller batches more frequently will yield better results than a large batch that sits and sits," advises Beckett.
If you're really dedicated to the cold brew cause and want to make your cold brew last longer, the one way to do it is to remove the air from the storage container (similar to a bottle of wine), notes Beckett. While impractical for most, there are some at-home devices available if you want to experiment. This is what coffee shops often do, putting their cold brew in a keg and "flushing it with carbon dioxide to make it fresher longer," Beckett notes. You can mimic the process at home if you have a small kegerator.
If optimal longevity is your aim, Viguera recommends keeping your cold brew in the fridge as a concentrate; you can then dilute it with water or milk as needed (diluting it earlier on may impact its shelf life). Lastly, in keeping with best food safety practices, Beckett recommends thoroughly washing your brewing device between batches.