Mozzarella Cheese

From Season 13: Ultimate Italian

For such a mild-mannered cheese, mozzarella sure is popular. In 2006, it passed cheddar to become the leading cheese in the United States in per-capita consumption, with most supermarkets stocking two main varieties: fresh (usually packed in brine) and low-moisture (available either as a block or preshredded). Both kinds are made by stretching and pulling the curds by hand or machine, which aligns the proteins into long chains and gives the cheese its trademark elasticity. However, the final products differ considerably, particularly when it comes to water weight. According to federal standards, fresh mozzarella must have a moisture content between 52 percent and 60 percent by weight, which makes it highly perishable. Drier, firmer low-moisture mozzarella hovers between 45 and 52 percent and is remarkably shelf-stable—it can last in the fridge for weeks.

We prefer the sweet richness and tender bite of the fresh stuff for snacking, sandwiches, and caprese salad but tend not to use it in cooked applications, since heat can destroy its delicate flavor and texture. For most baked dishes, we turn to the low-moisture kind: It offers mellow flavor that blends seamlessly with bolder ingredients and melts nicely in everything from lasagna to pizza. It’s a staple in the test kitchen and in many of our home refrigerators. But given mozzarella’s unassuming reputation, does it really matter which brand you buy?

We sampled nine nationally available brands of low-moisture supermarket mozzarella, both block-style and preshredded, made with whole or part-skim milk. Because we knew that the subtle (some would say “bland”) flavor of this cheese would be most easily assessed uncooked and unadorned, we first sampled the brands plain. But since low-moisture mozzarella’s biggest claim to fame is as “pizza cheese,” we also  melted the products on pizza. The perfect specimen’s profile: creamy and clean-tasting with a bit of soft (not rubbery) chew, plenty of gooey stretch, and just a touch of flavorful browning.

Block Party

Straight out of the package, the mozzarellas were surprisingly distinct (we’d carefully shredded the blocks beforehand to match the preshredded samples). Some boasted tender, supple chew and flavor so “fresh” that it reminded tasters of drinking milk. Others were rubbery and virtually tasteless. The worst samples were downright unpleasant—overly sharp or weirdly sweet as well as chalky. This tasting confirmed that when we ate block-style cheeses plain, we preferred those made from whole milk. In contrast, the three part-skim blocks in the lineup, all passable, hovered in the middle of the rankings, while three out of four preshredded part-skim cheeses lost points for an unpleasant powdery coating and flavor that was either weak or off-kilter.

Those results more or less held up on pizza, too. Even though the powder on the preshredded brands dispersed in the fat when the cheese melted, and tasters praised how the oven’s heat rendered them “gooey” and “bubbly,” these cheeses were criticized for being “bland” or “flat” and “sweet.” The lowest-ranked cheese in the plain tasting also failed on pizza; both times tasters noted the preshredded cheese’s objectionably sweet aftertaste. This sample was also pockmarked with overly dark, leathery patches. Most of the block samples, on the other hand, boasted richer flavor (including more oil on the surface), softer texture, more stretch, and just a little appealing browning.

So what, exactly, accounted for these differences? 

Cheese by Design

One obvious factor was that dusty coating. Manufacturers toss the preshredded cheese with powdered cellulose (and sometimes potato starch) to absorb moisture, which prevents clumping and slows spoilage. The powder itself is flavorless, but it can dull the flavor of already-mild cheese. The fat content in the cheeses also played a role in flavor. All of our top-ranked cheeses boasted more fat—between 6 and 7 grams per serving—than the low-ranked cheeses, which contained roughly 5 grams. As a result, these leaner samples were drier and less capable of melting cohesively. They were also unusually bland—or, worse, sour and sharp.

But beyond that, there were very few clues as to why some brands did better than others, as the ingredient and nutrition labels didn’t offer much insight. In fact, aside from variations in their dairy- fat content, the ingredient lists were virtually the same. Digging deeper, we learned that it was the manufacturing process that tweaks a cheese’s taste and alters its ability to shred, melt, stretch, brown, and bubble to an exact set of specifications.

That information is not easy to come by. While the U.S. Food and Drug Administration sets standards for the amount of moisture and fat in mozzarella, manufacturers aren’t required to reveal their processing methods or to spell out the exact form an ingredient may take in their product. For example, we learned from Dean Sommer, a cheese and food technologist at the Wisconsin Center for Dairy Research, that the “milk” listed on a mozzarella label can mean the fresh stuff—or it can mean a cheaper alternative like condensed skim milk or nonfat dry milk. Because condensed milk and nonfat dry milk have more sugars, Sommer said, they can lead to blistering and overbrowning in melted cheese—and oddly sweet, off-flavors. Conversely, the relatively small amount of sugar in fresh milk produces minimal spotting and, as a result, just a pleasant hint of sweetness.

It seemed obvious to us that some of the cheeses in our lineup weren’t made entirely from fresh milk. When we asked, only one manufacturer, would confirm that it allows processed milk products to be used in its mozzarella. Sure enough, that brand turned out to be the very same one that had placed in the bottom of the rankings for a sweet “cooked,” “flat” flavor. At the same time, a few companies—including the maker of our favorite mozzarella—stated outright that they use only fresh milk. Checking the labels, we found that one cheese listed 2 grams of carbohydrates per 28-gram serving; all the other cheeses in our lineup contained less than 1 gram. More carbs in the cheese means that its sweet taste likely derives from condensed or nonfat dry milk.

It turned out that some of the other flavors we noticed—sourness, tang, and even Parmesan- and cheddar-like sharpness—are products of aging. According to Sommer, while low-moisture mozzarella can be sold for up to 150 days after manufacture, the fresh milky taste begins to fade after two to four weeks. This is because the enzymes and starter cultures that turn the milk into cheese continue to break down its proteins into peptides, developing sour, tangy, or even bitter notes. One brand in our lineup said it deliberately targeted a later sale date—90 to 120 days after production—to create this more intensely flavored profile. But in the main, our tasters didn’t appreciate the age-related tang. Some sharpness on pizza was OK, but too much was distracting. And eaten out of hand, these samples got a near-unanimous thumbs-down.

The Cheese Stands Alone

As we looked at the averaged scores from the two tastings, two cheeses stood apart. One was our winner. Its gooey creaminess and clean dairy flavor were exactly what we wanted on pizza. Like all low-moisture supermarket mozzarellas, it doesn’t rival the just-churned taste of the fragile fresh kind, but it comes as close as this style of cheese can get. It was so good that we even found ourselves snacking on it straight out of the package.

The other standout was something of an anomaly. This was the lone shredded sample to make it into the upper half of the rankings. (We also liked the brand’s part-skim block mozzarella enough to rank it number two in the lineup.) The company wouldn’t disclose any manufacturing information, but this sample did have a little more fat than most of the preshredded cheeses. Although it didn’t dazzle us with its flavor, our tasters found it a reliable pizza topping—smooth and melty—and gave it convenience points for those times when we want shredded cheese at the ready.