There are so many things that can be done to help raw milk stay fresher longer. One of those is keeping raw milk stored in an air-tight container. I was using one of those neat plastic lids with the built-in handle and flip-top cap....the milk didn't last but four or five days. I switched to the metal ring and lid and am back to 10+ days. Even the plastic storage lids that everyone keeps requesting are not air-tight. Lay two jars on their sides, one with a plastic lid and one with a metal ring and lid, the jar with the plastic lid will leak.