The Three-Cheese Blend Behind Costco's Mac And Cheese

Costco's Kirkland Signature mac and cheese is the ultimate in take and bake convenience and comfort food all-in-one. It comes fully prepared, so all you need to do is pop it in the oven for 40 to 60 minutes until the cheese is gooey and melty. While there are plenty of copycat recipes out there and a lot of speculation as to what the ingredients are, the biggest mystery has been what kinds of cheese go into it. Costco described it on Facebook as cavatappi pasta that is "enrobed with our signature cheddar cheese sauce" and notes that it is freshly made in the deli department. But there's actually more to it than that.

The ingredients aren't really all that much of a mystery — in fact, they're printed right on the label. Rather than being just a basic mac and cheese recipe, it's made with a blend of three cheeses; along with shredded cheddar, it also contains Romano and Parmesan. That's where the plot thickens, however, because the Romano and Parmesan aren't put directly into the mix. They're actually ingredients that are in Alfredo sauce, which, aside from pasta, is the main ingredient in Costco's mac and cheese.

Both cheeses are typically used as creamy pasta sauce ingredients, along with cream, milk, and butter, which are all in Costco's version. The label reveals that the sauce is flavored with garlic, black pepper, and something simply identified as "spice" ... all of which combine to give the dish its primary flavors.  

Costco employees have shared online that the sauce used in the mac and cheese is store-bought Alfredo sauce from the company's vendor (per Reddit). This would explain why some people think it tastes exactly like the sauce used in the Kirkland Signature chicken penne Alfredo. In essence, Costco's version is really an Alfredo pasta that's topped with cheddar. This isn't to say that it isn't delicious, and it's not unusual for mac and cheese recipes to be made with similar creamy sauces, such as béchamel and Mornay. 

Still, one common complaint about the heat-and-serve dish is that it tastes bland. That's an easy fix — just mix in more salt (or garlic salt). To temper the Alfredo-dominant Romano and Parmesan blend, you can add more cheddar cheese for balance. For that matter, there are plenty of easy upgrades that you can make to improve the flavor, including adding in some protein to make it more of an entree than a side dish. 

Try sprinkling in some chili powder or paprika for color, heat, and smokiness. A splash of hot sauce will do the trick too. Throw in some veggies for freshness, like broccoli, peas, or spinach. Top the tray with your choice of breadcrumbs, bacon bits, or jalapeños before baking. For a heartier meal, stir in a helping of shredded Costco rotisserie chicken. Shellfish lovers will enjoy the addition of crab meat along with some Old Bay seasoning.