Just like tea, how long you steep cold brew coffee depends on the flavor and taste you're after. While the ideal time frame for steeping is between 18-20 hours, those who prefer a stronger, bolder taste can steep their cold brew coffee for up to 24 hours. Steeping it for longer than that may get flavors that are unpalatable, but you also run the risk of the drink itself going stale or the grounds going mouldy. Steeping it in the fridge can delay the latter from happening.