Brewing coffee doesn't expel a lot of water, so it freezes easily. You can freeze coffee either in bulk or by brewing a single cup and freezing it immediately after brewing. To make frozen coffee cubes: Pour coffee into a large sealable bag. Cut off one corner of the bag and use an ice cream scoop to fill the space below with water. Seal the bag and shake until the coffee is evenly mixed with water. Place the frozen coffee cubes in a container and store in the freezer for up to 2 months. Occasionally, press down on the frozen cubes to release liquid CO2 that has accumulated during storage.