With its Denominazione di Origine Protetta (D.O.P.) designation and noted 24 months (or more) of aging, Costco's Parmigiano Reggiano wheel is the real deal.

Parmigiano Reggiano is rich and nutty with a deep and complex umami flavor. Costco sells whole wheels for $949.99 — a good deal for those using the entire 72-pound wheel.

Real-deal Parmigiano Reggiano has to meet tightly controlled regulations. Parmesan cheese is made in the style of Parmigiano Reggiano, but it doesn't meet these qualifications.

Made from skimmed cow's milk, Parmigiano Reggiano must be made in one of five Italian provinces, aged at least two full years, and inspected by a master cheese grader.

Parmesan often doesn't carry the same depth of nutty flavor or have the same salty, crystalline texture that Parmigiano Reggiano does.

A Parm aged 24 months, like Costco's, has developed a more savory flavor. It builds on the fruity notes with hints of nuts and meats.

BJ's sells its D.O.P. 24-month Parmigiano Reggiano for $12.99 per pound, and Whole Foods’ version sells for roughly $22.99 per pound. Costco's cheese wedges are $11.49 per pound.

Most Parmesan cheeses rarely qualify as Parmigiano Reggiano, but Costco's version does. Considering import costs, competitor prices, and quality, Costco's cheese is quite the deal.