How we tested
It’s a tempting shortcut: spend a few more dollars for a bag of shredded cheese and save time—and potentially skinned knuckles—by not having to grate the cheese yourself. We usually prefer to shred our own mozzarella for pizza, pasta bakes, etc., since most pre-shredded cheese contains anti-caking agents like cellulose powder (miniscule pieces of plant fiber) that can make the cheese stiff and dry, but we wondered if there was a shredded brand that could work in a pinch.
To find out, 21 America’s Test Kitchen staffers tried seven brands of shredded mozzarella plain and melted on pizza. We also sent the cheeses to an independent lab to get a read on fat and sodium content.
Texture was the most glaring problem for most of the brands. None were great when eaten raw—the anti-caking agents made their strands gritty and powdery, and there was no fooling tasters into thinking this was freshly shredded mozzarella. But while tasters said no, grazie to the idea of eating pre-shredded cheese for a snack or atop a salad, most agreed that texture wasn’t as much of an issue when the cheese was melted on pizza. Though many brands were still unacceptably rubbery and stiff when melted, a handful emerged from the oven perfectly stretchy and chewy.
Why were some cheeses better than others when melted? The nutritional labels didn’t reveal any differences in the amount of cellulose powder or starch in each brand. Instead, lab tests pointed to fat as the culprit. Our winner—the only cheese made from whole milk in our lineup—contained 45% fat in its dry solids (a measurement of how much of the cheese is fat once water is removed). Lower-scoring cheeses (again, all made from part-skim milk) were significantly leaner, with between 36% and 41% fat in their dry solids. Fat helps cheese retain a tender, milky texture when melted, which explains why leaner products cooked up dense and rubbery, while fattier cheeses were more tender and stretchy.
Fat also contributes to flavor, so it was no surprise that lower-fat cheeses were seriously lacking in the buttery, rich flavor we expect from mozzarella. It didn’t help that some of these brands were also under- or over-salted; we found the sweet spot for seasoning to be between about 210 and 230 mg of sodium per serving—just enough salt to add a savory complexity that tasters craved. One other factor that contributed to flavor: Our winner was the only cheese that contains vinegar, and our tasters appreciated the tang it added. Testers also noticed that a few very finely shredded cheeses were clumpy and sticky, easily balling up into dense clumps that left the cheese splotchy and unevenly melted. When we measured individual strands with calipers, our favorite shreds were two or even three times thicker than lower-ranked products—about 2.8 millimeters compared to as little as 0.9 millimeters. Large, chunky strands were easy to sprinkle over the pizza, didn’t clump in our hands, and melted in uniformly browned sheets.
Our favorite cheese, Polly-O Whole Milk Shredded Low-Moisture Mozzarella Cheese, contained the most fat, a moderate amount of salt, and the thickest, chunkiest strands. Its superior flavor and higher fat levels can be attributed to the fact that it’s the only product made using whole milk and vinegar, just like our favorite block mozzarellas. Most products make their shreds leaner part-skim milk, and just couldn’t achieve the same bouncy, springy texture and rich tanginess as the Polly-O shreds.
Polly-O also makes our winning block-style mozzarella, and while it was clear from the lab results that the pre-shredded product is a different cheese from the block mozzarella, we decided to try them side-by-side. The block mozzarella was clearly superior when tasted plain, but the two cheeses were pretty close when melted. So if you’re tossing mozzarella into baked pasta or on top of a pizza, you can go ahead and buy our pre-shredded winner in a pinch.
Twenty-one America’s Test Kitchen staffers sampled seven low-moisture shredded mozzarellas in two blind tastings—plain and atop Sheet Pan Pizza. Sodium and percentage of fat in solids were measured and reported by an independent lab. We obtained thickness data by using calipers to measure five shreds from each product and averaging the measurements. Results from the tastings were averaged and products appear in order of preference.