I’ve got some shredded Costco cheese that I think has been in my fridge since around July or earlier (4 months). I just got back from a two week vacation and it has finally started to have a bit of mold. My question is what is the process that makes this cheese last nearly forever? It is a very fine grated cheddar colored substance. Granted, I no longer have the the original packaging, but it looks and kind of tastes like cheese. Any other cheese in my fridge goes south in less than 3 weeks, except for the stuff in the green can which has much lower moisture. I suspect it uses a similar technology. Do they tumble it it some super preservative?
Well, with some pasteurized cheese, it’s mold-free until mold is introduced from outside sources. Thus, it’s possible that no spores got in.
Note that Velveeta is sold un-refrigerated , and has a fairly good shelf-life until opened.
Did you ever check the salt content of Velveeta? Probably only supports seaweed 
Let me add that this cheese was opened in July and exposed to spores many times. The mold is black, and not the green penicillin mold I’m used to seeing on cheese.
This mysterious cheese probably has at least the salt content of velveta. Now that I think of it, Velveeta has a super long refrigerated shelf life even after opening, so maybe it shares some characteristics with the mysterious shredded cheese.
The cheese spent some time in the freezer, perhaps that kills the spores.
Salt is a major ingredient of cheese. The Tillamook cheese factory is a couple hours from here and whenever we travel that way we stop in to buy fresh cheese curd. We call it ‘squeeky cheese’ because it is kind of rubbery and makes a squeeky sound on your teeth when you bite it.
It is also quite salty.