mozzarella
Also known as: fresh mozzarella
A mild, stretchy Italian cheese sold two ways -- fresh, soft, and packed in water, or firmer and aged in a block for shredding. Its low salt and high moisture are what let it melt into long strands rather than pooling into an oily layer, but that same moisture makes it behave very differently from a hard aged cheese.
Buying guidance
Buy the form you need: fresh mozzarella for slicing and eating cold or barely warmed (it's too wet to shred well), low-moisture block mozzarella for melting onto something hot. A block you grate yourself melts more smoothly than pre-shredded, which is coated in anti-caking starch that can leave a topping grainy.
Substitutions
- Low-moisture block mozzarella in place of fresh, or the reverse -- fresh is wetter and milder, block melts more evenly under heat.
- Provolone -- similar stretch, a bit sharper.
- Fontina -- meltier and nuttier, with less of a pull.
Tips & common mistakes
Fresh mozzarella packed in liquid should be patted quite dry before it goes onto a hot surface -- the extra moisture it holds otherwise steams the surface and keeps it from browning or crisping.
Storage
Fresh mozzarella needs to stay submerged in its packing liquid to keep from drying out and is best used within a few days of opening; low-moisture block mozzarella keeps for weeks wrapped in the fridge and also freezes reasonably well for cooking use, since it's already firm rather than delicate.