Our milk usually keeps at least 8 - 9 days (but we usually use it up by then, so we aren't trying to keep it longer than that). We get about 2-3 gallons each week, in glass jars. I put it in the coldest part of the fridge, and open one jar at a time. The last jar is just as good as the first. If you can only pick up every two weeks, you might consider getting extra and freezing it, or getting it almost to freezing temperature so it will keep longer. Definitely put it in more containers so that you have to open it less frequently, and keep it in the coldest part of your fridge. Also, if it starts to sour before you run out, you can still use it for baking, smoothies, etc., where you won't notice the sour taste as much. Make sure you are getting the freshest milk you can, and that your farmer is chilling it down as rapidly as possible. That will help your milk stay fresh longer in your own fridge. Also, being super clean contributes to longer shelf life.
IME, cream does not last any longer than milk.
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