Mozzarella is a cheese with two distinct personalities. Aged, it's the ubiquitous cheese of choice for casseroles, pizza and so much more, mainly because it melts into a great mass of gooey, stringy decadence.

Fresh mozzarella is an entirely different product. It's a soft, stretchy cheese that tastes like the freshest milk you've ever tasted. Some versions taste as rich as butter; others sport the subtle sweetness of full-fat milk. And they're absolutely perfect, as legions of Caprese salad lovers will tell you, paired with ripe tomatoes, fresh basil and a drizzle of olive oil, all summer long.

But fresh mozzarella is a fleeting pleasure, a food so highly perishable that it must be eaten straight away. Tuck it away for later, and the cheese will be lost. So it's important to know what's what when you shop.

A southern Italian staple, a traditional Caprese Salad is a delicious way to spotlight fresh mozzarella.
A southern Italian staple, a traditional Caprese Salad is a delicious way to spotlight fresh mozzarella. (David Eulitt/Kansas City Star/MCT)

Here in California, there are two basic types: Fior di latte is made from cow's milk; mozzarella di bufala is made from water buffalo milk.

Most mozzarella di bufala is imported. Water buffalo require a lot of land and produce significantly less milk than their bovine sisters. A cow produces 8-12 gallons a day; a water buffalo yields about two gallons of high-quality milk with a deeper, more complex flavor. Buffalo milk is higher in calcium, fat and protein too.

No matter the milk source, mozzarellas are typically made with the same four ingredients: milk, salt, vinegar and enzymes or rennet. The difference between cheeses comes primarily from the quality and fat content of the milk. Higher fat generally results in better texture and flavor.

The age of the cheese is also key, because the texture changes as the cheese ages. The texture is firm and elastic when the cheese is very fresh. Within days, it transforms into a juicy, stringy, sometimes granular mass that's so soft it's almost spreadable. Texture preference is entirely personal, but be sure to check the expiration date on the package so you know what you are getting.

Local markets carry a few imported buffalo milk mozzarellas, which range from truly special to deeply awful. We tasted and rated eight brands. Here's the scoop.

Annabella Buffalo Cheeses

This Colombian import has a subtle blue cheese-like tang, super creamy texture, and just enough salt to maximize flavors. It's made from the milk of grass-fed water buffalo. An ounce has 7.3 grams fat, 85 calories. A 4.4-ounce package is $8.99. Available at Canyon Market and Rainbow Grocery in San Francisco, The Pasta Shop in Oakland, Piazza's Fine Foods in San Mateo and Palo Alto, Draeger's in Menlo Park and other specialty stores. (4 stars)

Mandara Mozzarella di Bufala Campana

This Italian import has a pleasantly earthy, grassiness and a distinctly tender, grainy texture with just a hint of salt. An ounce has 7 grams fat, 80 calories. A 7-ounce container of two balls is $6.99 at Trader Joe's. (4 stars)

Di Stefano Whole Milk Fresh Mozzarella

This snowy white, ultra-fresh tasting cheese is a great pick for those who prefer the more straightforward flavor of a cow's milk cheese. An ounce has 6 grams fat, 80 calories. An 8-ounce tub is $5.99 at Whole Foods. Even better is the burrata, the same cheese filled with a shot of cream. An ounce has 4 grams fat, 60 calories. A 4-ounce ball is $8.99 at Rainbow Foods. (3 ½ stars)

Primo Fresh Mozzarella

The sweet, bright flavor of fresh milk, a touch of salt and a buttery finish earned this Safeway brand high marks. An ounce has 5 grams fat, 70 calories. An 8-ounce package is $4.99 at Safeway. (3 stars)

BelGioioso Mozzarella Fresca

This domestic cheese is a solid choice. It's a bit bland and under-salted, but the mild buttery flavor gives it a pleasant finish. An ounce has 5 grams fat, 70 calories. An 8-ounce package is $8.99 at Safeway. It also comes in individually packaged bites that have a much longer shelf-life than most fresh mozzarellas. (2 stars)

Trader Joe's Ovoline

Even though this cheese tastes fresh, it's under-salted, and the lower fat content renders it dry and chewy. An ounce has 4.5 grams fat, 60 calories. An 8-ounce tub is $3.49. A better pick is the velvety, cream-filled burrata. An ounce has 6 grams fat, 80 calories. An 8-ounce tub of two large balls is $4.99. (1 ½ stars)

Galbani Mozzarella Fresca

This utterly forgettable, flavor-free version isn't offensive. It's simply bland. An ounce has 6 grams fat, 80 calories. An 8-ounce ball is $4.49 at Safeway. (1 star)

Rusticone Euro Pomella

This Italian import gets a half-star for promise. It should have been great, but the cheese was clearly compromised along the way, resulting in a slimy texture and sour, rotten flavor. An ounce has 8 grams fat, 90 calories. A 7-ounce tub is $9.99 at Gene's Fine Foods in Pleasanton. (½ a star)

Reviews are based on product samples purchased by this newspaper or provided by manufacturers. Contact Jolene Thym at timespickyeater@gmail.com. Read more Picky Eater at www.thepickyeateronline.com.