Can Leaving Cold Brew Coffee Out At Room Temperature Make You Sick?

Smooth, sweet and layered with delicate flavor, cold brew has quickly become the go-to chilled coffee of choice for Americans. In fact, Statista reports that by 2025, the market for cold brew is expected to reach over $900 million! Whether you make it at home or rely on your local coffee shop for the best cold cup of joe, it's fair to wonder just how long it can keep when left at room temperature. 

Unlike iced coffee brewed with hot water and then chilled, Cold Brew Lab explains that cold brew coffee uses room temperature or cool water and allows the grounds to steep anywhere from 12 to 24 hours, before being strained. While the process is far lengthier, there are certain benefits when it comes to taste. Since heat can result in astringency, Cook's Illustrated explains that cold brew can actually taste significantly less bitter, allowing subtle flavors from the coffee beans to shine.

While there are different philosophies on whether or not you should make and store cold brew in the fridge or at room temperature, can the latter actually make you sick?

It won't hurt, but it will taste different

Unopened bags of coffee beans can last about 6 months when stored in a dark, cool location. But Drip Beans explains that once steeped, cold brew can last for about 2 weeks in the fridge — but only 2 days when stored at room temperature. Unless you've added dairy to your cup of cold brew (which can spoil and cause food poisoning), Well+Good notes that drinking coffee that's left out at room temperature is pretty safe, as the bacteria isn't likely to grow at the same rate. 

However, the quality of your cold brew will start to take a hit with the passage of time. Just like most foods and beverages, cold brew can fall prey to oxidation. When exposed to air, it changes in composition and deteriorates, resulting in discoloration, mold, weak or rancid aromas, and stale flavor, reports Drink Golden Ratio. Should your room temperature cold brew exhibit any of these warning signs, it's best to toss it and start prepping the next batch.