Re: Lipase issue ?
If your milk still tastes good after 7 days you should be in the clear. I've only checked for the effect in fresh milk kept in the refrigerator, though. I know that freezing does not deactivate the enzyme, but I'm not sure if activity slows at certain temperatures or not. To be certain about it, you might want to keep an ounce of fresh milk in the refridgerator for a week and periodically smell and taste it rather than tasting thawed frozen milk.
K. Sophia - Mama to my little lactivore, the amazing Mr. X (11/10).