I asked Mike at @Kalm with Kava whether or not it the Guava or Kavarita concentrates needed to be refrigerated after opening. This was his response: "It's best if it is [refrigerated] as it will last longer. Shelf stability is 6 months unopened unrefrigerated and 12 months unopened refrigerated. " "At the very least 1 month opened unrefrigerated and 3 months opened refrigerated. Also, there will be settling so it's best to shake the bottle before each use. "