A year ago, I tried to find out from Hormel the difference between their sliced retail, club pack, and foodservice pepperoni. My emails went unanswered and a rep from the retail side wouldn't tell me or didn't know herself. This effort is in support of our efforts to recreate Shakey's pizza, and we are fairly certain Shakey's corporate restaurants are currently using Hormel foodservice pepperoni.
Hormel's foodservice website notes that a number of their products in this line are "fresh", and state it must be refrigerated. The retail products are apparently shelf stable, though most supermarkets sell them out of a refrigerated case. In particular, I have bought the three pound club pack "pillow packs". This label does not indicate the product must be refrigerated before opening.
In early August I bought a 12.5 pound bag of 16 slice to the ounce "fresh" pepperoni, Hormel product number 31763, for about $35 from a foodservice cash-and-carry. I immediately packed most of it into plastic sandwich bags, 45 slices to a bag, and froze it. My goal was to see how the fresh product performed on our Shakey's knockoff crusts, and how long the product would remain usable. I used a lot of the pepperoni so far to make pepperoni and cheese/club/turkey/BMT etc. sandwiches. On the pizzas, it seemed to perform slightly better than the shelf-stable retail variety, possibly because the slices were thinner. There appeared to be less grease. They are a dead ringer for the pepperoni used on our samples of genuine Shakey's pizza.
In early December (or 4 months later), the first batch could no longer be used for sandwiches because they had the taste of stale deli salami. The second batch, packed earlier after opening the bag and stored in a colder part of the frezer, is still usable. I always remember the retail pillow packages of Hormel pepperoni still usable after freezing them for four months, even with pillow pack opened and tightly resealed.
So this is my experience with using what the pizzerias use. Still looking for what the differences in formula and processing are between Hormel's foodservice and retail pepperoni are.