I recalled an old thread where the comment that x number of days after manufacture date should be the cutoff for mozz. I did a significant amount of searching and found this NicksPizzaActive Member You may also be running into a cheese age issue. Even the best of cheeses will oil out and curdle after it gets too old. Check the manufacture dates on the cheeses as you get them. 45 days after manufacture seems to be the date I recall being red flag time. Others may correct me on this one. The cheese I received today has a date code of 20119 , which means it was packaged on Jul 20 so is 40 days old. It won't be completely gone for 9 to 10 days so it will be 50 days old. I noticed it because we have had the same date code and color coded tape for 3 weeks. Is 45 days the standard? Should I anticipate problems? So far I haven't noticed excessive oil on the pizzas but I am concerned.