I get asked this a lot and my answer is: it depends.
In my experience, Mbrz milk stays fresh tasting for 5-10 days from when you receive it, depending on a number of factors. Temperature, light, vibration and air exposure will all negatively effect the taste. For instance heat promotes the production of lactic acid, which causes a sour flavor, though this doesn’t mean it’s “bad.” In fact, the probiotic content is higher, but it might not taste as good when drunk fresh. So here are some tips:
- Keep it cold. The back of the fridge is best.
- Keep it in the dark as much as possible, including while transporting it home.
- Keep the air out. As you empty your carton, transfer the contents to smaller glass containers to minimize air exposure.
- Keep it still. Don’t ever vigorously shake the milk – this causes oxidative damage. Just gently turn the bottle upside down a few times to blend the cream layer before pouring. Also remember that the cream layer creates a nice natural barrier between the oxygen on top and the milk proteins below.
Once the milk begins to turn (it goes sour – but is NOT bad), I would start using it in pancakes or soups or for yogurt or kefir – or fertilizer for your plants. Here’s a great article on 101 uses for soured milk.
What about freezing the milk? In my experience, sheep and goat milk freeze and thaw just fine, but cow milk’s ends up with an unpleasant, sort of a grainy texture from the fat particles.
That’s why I think that the traditional preservation methods of fermentation are the best way to go. Yogurt, quark, cheeses (fermentation + salt), kefir, clabbered milk, etc. are all methods of preservation through fermentation.