If you're talking about that stuff in a green can that you can buy on the shelf, I think what I've seen online is true: "If you buy the finely grated Parmesan cheese in the green can, take a look at the label. It says do not refrigerate - even after opening!"

That's probably because of the processing it's been through, and the additives, preservatives, etc.

If you're talking about "real" parmesan cheese though (in a hunk, or already shredded or grated) sold in the refrigerated sections, it will keep longer if cool, but should last a long time if just air-tight since it's a very "hard" cheese. Either way it will continue to "ripen" but much slower in cooler situations.

To save money but have parmesan on hand all the time, I keep a wedge (of fresh parmesan) in the freezer inside a ziptop bag, then just grate off as much as I need at any time. Parmesan basically lasts forever in the freezer as long as it's kept air-tight, it grates well from the freezer, saves money, and tastes much better than that stuff in the can unless you're really craving a very strong *pungent* flavor (and some people like it on popcorn).

things like the parm cheese, romano cheese, and herbs/spices do not need to be refrigerated.

I always store things according to the part of the grocery store I get them from. If not sold refrigerated they go on the shelf, if sold refrigerated they go in the fridge!!

since we almost quit eating pastas, due to my food plan, I refrigerate the cheeses or they do go bad!

Just put it in the refrigerator. It lasts a long time.

definitely in a fridge, fortunately it doesn't last in my house, it gets used right away. under buy when buying cheese, better to buy a little than too much, that way you will have fresh. and buy from a cheese shop, better quality, knowledge of what you can use it for, and fresher than a supermarket

I always refrigerate.

you store it in a fridge, just like you would cheddar or swiss cheese.