Copycat Costco Mac and Cheese: The Tested Recipe That Tastes Exactly Like the Deli Tub

If you’ve ever pried the lid off Costco’s deli mac and cheese and wondered why it tastes better than anything you make at home, the answer is on the label — and it’s simpler than you’d think. This is the closest copycat I’ve been able to dial in after a stack of side-by-side tests, and it gets there with three cheeses, one pan, and a couple of small technique fixes most recipes get wrong.

If you’ve ever pried the lid off Costco’s refrigerated mac and cheese, scooped a cold spoonful straight from the tub, and wondered why it tastes better than the one you make at home — you’re not alone. The deli mac has a cult following for a reason: it’s stupidly creamy, sharply cheesy without being one-note, and it bakes into something that’s somehow both gooey and structured.

This is the closest copycat I’ve been able to dial in after a stack of side-by-side tests. The trick isn’t a secret ingredient. It’s three things most home cooks get wrong: the cheese ratio, the sauce temperature when you add the cheese, and how long you bake it. Get those right and you’ll stop buying the tub.

What’s Actually in Costco’s Mac and Cheese

Before reverse-engineering anything, it helps to read the label. Costco’s Kirkland Signature Macaroni & Cheese (the refrigerated heat-and-serve tub from the deli section) lists, in order: cooked cavatappi pasta, a cream-and-cheese sauce built primarily on cheddar with Romano and Parmesan, butter, milk, modified food starch (their thickener instead of a flour roux), and a short list of seasonings dominated by salt and a touch of white pepper.

A few things jump out from that ingredient list:

• Cavatappi is non-negotiable. The corkscrew shape catches sauce in its ridges and inner channel — elbow macaroni is half as efficient at this.
• Cheddar is the dominant cheese, not Parmesan. Most copycat recipes online get this ratio wrong and end up too salty and one-dimensional.
• The Italian cheeses are supporting actors, not the lead. They add sharpness and that nutty, savory backbone, but cheddar carries the body.
• White pepper, not black. It’s a small detail but it’s why Costco’s version has no visible specks and the heat is clean rather than peppery-sharp.
• No mustard, no nutmeg, no Gruyère. Costco keeps it simple. Resist the urge to “elevate” it — the restraint is the point.

Why This Recipe Works

Most copycats fail in one of two ways: the sauce breaks (oil separates, cheese goes grainy) or it bakes into something stiff and dry. Both have the same root cause — heat management.

A good cheese sauce holds together because the proteins in cheese stay emulsified with fat and liquid. Push the heat too high and those proteins seize up, squeezing oil out. The fix is to build a stable base (the roux thickens the milk so it can carry the cheese without breaking), then pull the pan off the burner before adding cheese. Residual heat melts it gently.

The bake is the second half of the equation. Costco’s mac has that just-set, gooey-but-not-soupy texture because it’s baked covered, briefly, at moderate-high heat. Too long and the pasta absorbs the sauce and goes claggy. The recipe below times it to land in the sweet spot.

Ingredients

Pasta:

• Cavatappi pasta: Corkscrew shape catches sauce in every ridge.

Cheese sauce:

• Unsalted butter: Forms the roux base for the cheese sauce.
• All-purpose flour: Thickens the sauce and prevents cheese from breaking.
• Heavy cream: Adds richness and stabilizes the sauce structure.
• Whole milk: Balances the cream without thinning the sauce.
• Sharp cheddar: The dominant cheese carrying body and flavor.
• Pecorino Romano: Italian sheep’s milk cheese adds savory depth.
• Parmigiano-Reggiano: Nutty, salty backbone that supports the cheddar.
• Kosher salt: Seasons the sauce and amplifies the cheese flavor.
• Ground white pepper: Clean heat without visible black specks.
• Sweet paprika: Adds warm color and subtle background flavor.
• Garlic powder: Rounds out the seasoning without overpowering.

For the top:

• Sharp cheddar — Reserved for the gooey melted top layer.

Ingredient notes

• Shred your own cheese. I know it’s annoying. Pre-shredded cheese is coated in potato starch and cellulose to keep it from clumping in the bag, and that coating actively prevents smooth melting. The sauce will look grainy. This is the single biggest variable separating a passable copycat from one that’s indistinguishable from the original.
• Use Pecorino Romano, not domestic “Romano.” The Italian sheep’s milk version has the savory, almost funky edge that Costco’s mac has in the background. American Romano is milder and slightly tangy — fine in a pinch, but you’ll taste the difference.
• Heavy cream is doing structural work. Substituting all milk gives you a thinner sauce that breaks more easily. Half-and-half is the only acceptable swap and you’ll lose a little richness.
• Sharp cheddar over mild. Mild cheddar gives you texture without flavor. You need the sharpness to stand up to the cream.

Step-by-Step Instructions

Step 1: Shred and grate all three cheeses before you start cooking. Once the sauce comes together you won’t have time to grate. Set aside 1 cup of the cheddar for the top.

Step 2: Bring a large pot of well-salted water to a rolling boil. Add the cavatappi and cook for one full minute less than the package directs. It will finish cooking in the oven, and undercooking it now prevents mushiness later. Drain but do not rinse — you want the surface starch to help the sauce cling.

Step 3: In a large heavy-bottomed saucepan or Dutch oven over medium heat, melt the butter. When it stops foaming, sprinkle in the flour and whisk constantly for 90 seconds to 2 minutes. The mixture should bubble and smell faintly like pie crust — that’s the raw flour taste cooking out. Don’t let it brown.

Step 4: Pour in the milk and cream in a slow stream while whisking. Keep whisking until smooth, then let it come up to a gentle simmer. It’ll thicken noticeably in 3 to 5 minutes — when it coats the back of a spoon and a finger swipe leaves a clean line, you’re there.

Step 5: Whisk in the salt, white pepper, paprika, and garlic powder now. Seasoning the base liquid distributes flavor better than salting after the cheese. This is the step everyone skips. Cheese added to a simmering sauce will break. Take it completely off the burner.

Step 6: First add the Romano and Parmesan, whisking until fully melted and smooth. Then add 8 oz (2 cups) of the cheddar in handfuls, whisking after each addition. The residual heat will melt everything. If you have any stubborn lumps, put the pan back over the lowest possible heat for 30 seconds while stirring.

Step 7: Add the drained cavatappi directly to the sauce pot and fold gently until every piece is coated. The sauce should look almost too loose — that’s correct. The pasta will absorb some during baking.

Step 8: Pour into a buttered 9×13-inch baking dish. Spread evenly. Scatter the reserved 1 cup of cheddar across the top. Preheat oven to 400°F. Cover the dish tightly with foil and bake for 20 minutes. Then uncover and bake another 3 to 5 minutes — just until the cheese on top is fully melted and starting to bubble at the edges. You do not want a deep golden-brown crust. Costco’s version has gooey melted cheese on top, not a casserole crust. This lets the sauce set just enough to scoop cleanly without going stiff.

The Most Common Mistakes (and How to Fix Them in Real Time)

• The sauce went grainy. You added cheese to a too-hot sauce or used pre-shredded cheese. To rescue: whisk in 1 to 2 tablespoons of cold cream off the heat. Often this re-emulsifies it.
• It tastes flat. Almost always under-seasoned. Costco’s mac is saltier than people remember. Taste before baking and adjust — a ¼ teaspoon more salt usually fixes it.
• It’s gluey or stiff after baking. Pasta was cooked too long before baking, or it baked too long. Next time, undercook the pasta by 90 seconds and pull the bake at 20 minutes covered.
• It’s swimming in liquid. Sauce wasn’t thickened enough before the cheese went in. Your béchamel needs to be visibly thick — like a pancake batter — before any cheese hits it.
• The top didn’t melt right. Cheese was cold from the fridge. Let shredded cheese sit at room temperature while you make the sauce so it melts evenly.

Make-Ahead, Storage, and Reheating

• Assemble ahead. You can build the whole thing through step 9, cover, and refrigerate up to 24 hours. When you’re ready to bake, add 8 to 10 minutes to the covered bake time since it’s going in cold.
• Refrigerator. Leftovers keep 4 days in an airtight container. The texture changes — the sauce thickens as the pasta absorbs more of it — but a splash of milk during reheating brings it back.
• Freezer. Freeze in a covered baking dish or portioned containers up to 2 months. Thaw overnight in the fridge before reheating. The texture survives freezing better than most pasta dishes because of the high fat content.
• Reheating. Oven is best: 350°F, covered with foil, with 2 to 3 tablespoons of milk stirred in to loosen things up. About 20 minutes from refrigerated, 35 to 40 minutes from frozen. Microwave works for single portions if you stir halfway through and add a splash of milk.

Scaling for a Crowd

Costco’s tub is roughly 4 pounds and feeds 6 to 8 as a main. This recipe matches that. To feed a true crowd:

• Double batch (feeds 16): Use a deep half-sheet pan or two 9×13s. Increase covered bake time to 25 minutes.
• Triple batch (feeds 24): Make the sauce in two batches rather than one giant pot — you’ll get better cheese emulsification. Bake in two pans.

The recipe scales linearly except the cooking times. Larger volume needs slightly longer in the oven, not proportionally so.

What to Serve With It

Mac and cheese this rich wants something cutting alongside it. The pairings that work best:

• A sharp green salad. Arugula with lemon vinaigrette is the best counterweight to all that dairy.
• Smoked or roasted meats. Brisket, pulled pork, smoked sausage, rotisserie chicken. The smoky char plays well with creamy cheese.
• Pickled vegetables. Quick-pickled red onions or cornichons cut through the richness.
• Roasted broccoli or Brussels sprouts with a hit of lemon and chili flakes.

Skip another creamy side. You don’t want mashed potatoes next to this.

Variations Worth Trying

Once you’ve nailed the base recipe, a few additions hold up without losing the Costco character:

• Crispy topping. Mix ½ cup panko with 2 tablespoons melted butter and a pinch of salt. Sprinkle in the last 5 minutes of baking.
• Bacon. Cook and crumble 6 strips, fold half into the sauce, sprinkle the rest on top after baking.
• Lobster. Fold in 8 oz cooked, chopped lobster meat with the pasta. This is wedding-mac-and-cheese territory.
• Buffalo. Add 2 tablespoons of Frank’s RedHot to the sauce and serve with crumbled blue cheese on top.
• Truffle. A teaspoon of truffle oil drizzled over the finished dish — never in the sauce, where the heat kills it.

Frequently Asked Questions

Is this exactly the Costco recipe? No copycat is exact — Costco uses a commercial cheese sauce concentrate with modified starches we can’t perfectly replicate at home. But this version matches the flavor profile and texture closely enough that side-by-side blind tasting fooled three out of four testers in my household.

Can I make it on the stovetop without baking? Yes. After folding the pasta into the sauce, serve immediately. You’ll lose the slightly-set baked texture but the flavor is identical. Use only 8 oz of cheddar total (skip the reserved cup for the top) if you go this route.

What pasta does Costco actually use? Cavatappi — the corkscrew-shaped tube pasta. It’s confirmed on the ingredient label. Other shapes work but won’t taste quite the same; the sauce-to-pasta ratio depends on cavatappi’s specific surface area.

Can I use a different cheese? You can, but it stops being a Costco copycat. Gruyère makes it more sophisticated, Fontina makes it stretchier, mozzarella makes it blander. The cheddar-Romano-Parmesan trio is what makes it taste like Costco.

Why white pepper instead of black? Two reasons: visual (no black specks in a pale yellow sauce) and flavor (white pepper has a cleaner, slightly earthier heat that doesn’t compete with the cheese). Costco’s version uses white pepper based on the label.

How long does it keep at room temperature? Two hours maximum for food safety. After that, refrigerate or discard. Dairy-heavy dishes are not buffet-friendly past that window.

Can I use evaporated milk instead of cream? Yes, and the sauce will actually be more stable — evaporated milk has a higher protein concentration that resists breaking. You’ll lose some richness. Use 1½ cups evaporated milk plus 1½ cups whole milk, skip the heavy cream.

Why did Costco’s stop being available in the deli? Availability varies by warehouse and season. Many locations carry it year-round in the refrigerated prepared foods section; others rotate it out. This recipe means you don’t have to track it down.

Can I use gluten-free pasta? Yes. Use a high-quality GF cavatappi or fusilli (Jovial and Barilla both work). Cook it 2 minutes less than the package says since GF pasta turns to mush faster. You may also want to use 1 tablespoon cornstarch instead of flour in the roux, mixed into the cold cream first.

Is this kid-friendly? Yes — it’s basically what kids think of as “real” mac and cheese. The Romano and Parmesan add depth without strong flavor, so even picky eaters tend to love it.

More Easy Recipes

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Copycat KFC Macaroni and Cheese Recreate KFC’s creamy side at home with this dialed-in copycat. Quicker and lighter than the Costco version, but every bit as satisfying.

Easy Copycat Olive Garden Mac and Cheese Restaurant-style ultra-creamy mac and cheese, ready faster than waiting for a table. The velvety sauce competes directly with the Costco deli tub.