Although some believe keeping coffee grounds in a freezer can help maintain the freshness, the opposite is true. When you store it in the freezer or refrigerator, moisture condenses on the coffee and can extract the flavor.
As briefly mentioned above, coffee should be stored in an opaque, airtight container at room temperature. Ideally, it should be kept away from sun exposure and any appliance that gives off heat like your oven.
HOW LONG CAN BREWED COFFEE SIT OUT?
Coffee will always taste fresh immediately after brewing. However, the vessel you put it in can help you prolong the fresh taste of your brewed coffee.
For instance, brewed coffee kept in an open container, like a glass carafe or even a coffee cup, could taste fresh for around 30 minutes. Since the coffee is exposed to air, it will oxidize quicker, losing its fresh taste over time. Instead, keep brewed coffee in a thermal carafe or in an airtight thermos. This will allow your coffee to taste fresh for a few hours.
Any unused coffee can be made into coffee ice cubes by pouring into an ice tray and storing in the freezer. Just add a few cubes to a freshly brewed cup for a simply delicious iced coffee.