there has been some discussion about this mozzarella recently. Craig has mentioned that you have to watch the dates at Costco, which I find to be true here too. I bought some this week and had one ball left from the previous bag. The difference in the cheese was noticeable in looks. For melt the mozz on the left is the new cheese, right older cheese. My goal was to taste both on the pizza but I got to involved with the pizza making and it never happened.
the mozz unbaked - left sell by date of 7/31, right sell by date of 7/11
on the pizza - 7/31 on the left, 7/11 on the right (you can see the division based on the three basil spots at the edge)