The other day, Joe picked up a container of milk and wanted to know what haltbar meant. Because of how it’s used on the milk container — mindestens haltbar bis — he thought it might mean “fresh.” But it doesn’t. The German suffix, –bar, attaches to verbs and generally means “able to be [fill in the blank with your verb]ed.” Thus, when you reach a German’s voicemail, the automatic recording tells you that the person you’re calling is nicht erreichbar — unable to be reached. A German warning label might say, “Achtung! Brennbar!” — “Warning! Flammable!” And a German friend might say that a song is tanzbar — able be danced to. (Offenbar throws us a slight curve, though — it means something is obvious.)
So back to Joe’s question about mindestens haltbar bis. It means the milk is haltbar able to be held mindestens at least bis until the date printed on the carton.