freezing yogurt

[GLC1968]

And here's the next question: when you ferment milk into yogurt, does that prolong the life of the milk, i.e. if milk was to expire say May 20, could I extend the life of the milk as yogurt because it's been fermented?

Yes. Plus, expiration dates on milk are pretty arbitrary, so don't go by that. If the milk tastes fine, drink it. If it's off, toss it. I've had milk go bad long before the expiration date (probably due to improper handling) and I've had it last well past the date (particularly if it's skim) as well.

But yes, turning milk into yogurt will make it last longer than if you left it as milk.