How long does cold brew last?

In an airtight container in the fridge: 7–14 days. It tastes best during the first 5 days. Undiluted concentrate lasts longer than pre-mixed beverages. Mold or a sour smell means: down the drain.

Why that is

Cold brew has a significantly longer shelf life than hot-brewed coffee — for several reasons. Cold extraction produces fewer acids and compounds prone to oxidation. Furthermore, cold brew is stored cold right from the start, which slows down flavor degradation.

Shelf life by state:

• Undiluted concentrate (1:5 to 1:8): 10–14 days in the fridge. The high concentration inhibits bacterial growth. Always store in an airtight container — open vessels absorb fridge odors.
• Diluted cold brew (ready-to-drink): 3–5 days. By diluting it with water, the concentration drops, making it easier for bacteria to grow.
• Cold brew with milk: 1–2 days. The milk is the limiting factor — it spoils faster than the coffee.

Optimal flavor: The first 3–5 days after brewing. During this time, the flavors are freshest and most intense. After a week, the taste becomes increasingly flat and dull — drinkable, but no longer at the level of the first few days.

How to tell if cold brew has gone bad:

• A sour, fermenting smell (not to be confused with normal light coffee acidity).
• Visible mold on the surface.
• Slimy consistency.
• A strongly altered, unpleasant taste.

Tips for maximum shelf life:

• Store the concentrate undiluted; mix it just before drinking.
• Use glass bottles with screw caps — glass doesn’t absorb odors.
• Filter out the coffee grounds completely — residue accelerates spoilage.
• Do not leave it out at room temperature — always put it back in the fridge.

In practice at Green Wall Coffee

At Sophienstraße 27, we brew fresh cold brew every 2–3 days — this ensures it is always in its optimal flavor window. For home use, I recommend brewing a liter once a week and storing it as a concentrate in the fridge. That will last you the whole week.

Come visit us at Sophienstraße 27 — Mon–Fri 8am–5pm, Sat 10am–5pm.