The Surprising Reason Pre-Shredded Cheese Melts Weirdly

If you’ve ever topped a lasagna with pre-shredded cheese or made grilled cheese sandwiches and noticed that the cheese wasn’t as gooey or didn’t melt as well as when you shredded your favorite cheese from a block, there’s a reason for this that’s based in science.

Ask the experts and they’ll tell you that the meltability and stretchability of cheese depend on five key things: shred size, type (different cheeses have different moisture and fat content), calcium levels (too much calcium in cheese will cause it to not melt), pH levels (too low or too high will affect meltability) and the cheese’s age, says Jill Allen, director of product excellence in research and development at Tillamook.

“Cheese that’s too young won’t melt,” Allen says. “And cheese that’s too old will be too weak and won’t stretch.”

So what’s the difference between a block of cheese and a bag filled with shredded cheese? Turns out, shredded cheese is coated with anti-caking agents such as cornstarch, cellulose gum (made of cotton, wood pulp and potato starch) and natamycin, a mold inhibitor, all of which work together to keep the strands from clumping together—and keep mold away.

And since these agents coat the outside of each individual piece of cheese, when the cheese melts, the agents form an outer shell around each strand and prevent it from spreading, thus retaining its original firm and separate form. 

“While the proportion of coating to cheese is minuscule, it keeps the shreds from melting as evenly as they would if you shredded cheese yourself,” says Chad “The Cheese Guy” Galer, who has served for years as a judge in international cheese competitions. “This process gives the shreds a slightly drier texture, too,” he adds.

So if the cheese melt is critical for maximum creaminess, it’s best to use a food processor or cheese grater and shred or crumble the cheese right before you need it—even if that means more meal-prep time.

“In dishes like pizza where the cheese melt is front and center, it may be worth the effort to shred the cheese from the block,” Galer says. 

3 Ways to Cook with Packaged Shredded Cheese

 If you’re prepping a recipe and realize you only have shredded cheese in your fridge, not to worry. Here are three ways to work with it.

1. Let It Sit on Your Counter

If you have the time, leave your bag of shredded cheese on the kitchen counter for about 20 minutes until it reaches room temperature while you prep everything else. If you try to melt cheese when it’s cold, it may melt slowly or unevenly, suggests Alexandria Hardy, RDN, a registered dietitian nutritionist in Lancaster, Pennsylvania. “Room-temp cheese will melt better than a bag straight out of the fridge,” she says.

2. Add a Starch

If you’re planning to use shredded cheese to make queso or Mornay sauce, for example, consider mixing 1 to 2 tablespoons of cornstarch with the shredded cheese. “Starches can work as thickeners,” Hardy says. “This helps hold the sauce together and prevent clumps.”

3. Rinse It

Yes, there are plenty of TikTok videos extolling the virtues of rinsing and straining shredded cheese to make it creamier, but this is a time-consuming process and there’s no hard evidence that this will work to make your cheese creamier than freshly shredded or straight-from-the-bag shredded cheese. “Rinsing will remove the anti-caking agents, which is likely what causes the cloudy water you see in those videos,” Hardy says. “If you want to try it, make sure to use cold water (as warm water can cause premature melting), dry thoroughly and use the cheese right away to prevent mold and future clumping.” 

The Bottom Line

For the smoothest melting, start with a block of cheese and shred it yourself. If you do use pre-shredded cheese, note that it might not melt as well due to anti-caking agents mixed with the cheese. You can try leaving pre-shredded cheese out on the counter for 20 minutes before using it to help it melt better.