Cold brew coffee is steeped cold and stored in the fridge, but it doesn’t last forever. Yes, cold brew can go bad—it can grow mold, taste off, or lose flavor. This guide covers how long cold brew typically lasts, how to store it, and how to tell when it’s time to toss it. For making great cold brew in the first place, see our best coffee for cold brew guide.

How Long Does Cold Brew Last?

Concentrate (undiluted) stored in a sealed container in the fridge is usually good for about 5–7 days. Some people keep it up to 2 weeks if the container is very clean and the fridge is cold, but flavor and freshness drop after the first week. Diluted cold brew (already mixed with water or milk) will go off faster—drink within 2–3 days. The less air and the colder the storage, the longer it keeps. Use a clean, airtight bottle or jar; avoid leaving it at room temperature for long.

Signs Cold Brew Has Gone Bad

Smell: If it smells sour, musty, or off, don’t drink it. Taste: A sharp or funky taste means it’s past its prime. Mold: Any visible mold or film on the surface—discard the whole batch. Separation or cloudiness: Some separation is normal; heavy cloudiness or chunks are not. When in doubt, throw it out. Fresh cold brew should smell and taste clean and coffee-like.

How to Store Cold Brew

Container: Use a clean, airtight bottle or jar. Glass or BPA-free plastic is fine. Temperature: Keep it refrigerated at all times after brewing. Dilution: Store as concentrate and dilute when you drink; that keeps it stronger and often fresher longer. Cleanliness: Wash the container well between batches to avoid bacteria or residue. For brewing tips and bean choices, see best coffee for cold brew and best coffee makers.

Conclusion

Cold brew can go bad: typically good for 5–7 days in the fridge in a sealed container. If it smells or tastes off, or you see mold, discard it. Store concentrate cold and dilute when you drink. For more on cold brew, see our best coffee for cold brew guide.

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