The mystery of the rank Reggiano

Find a person who has tasted really good Parmigiano-Reggiano (P-R), and you will have found a person who will tell you that there is no substitute for P-R.  It's a high-class cheese with a high-class price to match. 


From Wikipedia.

Given the legendary quality of this stuff, imagine my surprise when I brought one of these little expensive grated P-R tubs home from a League City grocery store the other day, only to find that it smelled overwhelmingly of the chemical solvent acetone. 

One of these things. 
You can find them in the deli section.

Cheese can, indeed, smell like many pungent things, but in my experience, acetone is not one of them.  I thought it must have been a freak occurrence of some kind, so I went back tothe store for a replacement today.  To confirm the quality, I discretely cracked open the lid of a new tub and took a whiff.

• Acetone.  Big time. 

So I reached all the way to the back of the cold case and yanked out another.

• No acetone whatsoever.  Smelled completely normal and fresh.

Huh??  Time to consult the all-seeing, all-knowing internet.  I gleaned a very concise explanation from this URL: 

To deter any off flavors, either grate Parmigiano-Reggiano and refrigerate or grate and keep it at room temperature. These two methods should never be mixed. Exposing the grated cheese to a combination of cold and then room temperatures can create an off acetone-like aroma in the cheese.

Upon reflection I realized, yes, this makes perfect sense.  That grocery store had been storing its grated P-R at room temperature in a center display aisle, and then they moved it all to the cold case, thereby apparently ruining most of their stock - all except for the brand new stock at the very back of the display case.

So file this little tidbit in your "learned something new today" category, and remember to sniff your P-R before you pay for it.  Those little tubs cost about ten bucks apiece, so you don't want to take home a dud that has been mis-handled by grocery store personnel.  And then once you get it home, maintain the temperature at which you found it in the store.