Why did my cheese go stringy or oily when melted?

Cheese is protein holding fat and water. Heat it too far and the protein tightens and squeezes the fat out, which is exactly what an oily puddle on a pizza or a stringy sauce is.

Step by step

1. Choose a cheese that melts.Mozzarella, cheddar, gruyère, emmental, comté, fontina, raclette. Very hard aged cheeses like parmesan and pecorino are for flavour, not melting, and fresh cheeses like feta and halloumi soften rather than melt.
2. Grate it finely.Fine gratings melt quickly at low temperature. Chunks need more heat to melt, and that heat is what causes splitting.
3. Add it off the heat for sauces.The residual heat is enough. Cheese added to a simmering sauce splits within seconds.
4. Use moderate heat for grilling and baking.A very hot grill browns the top before the cheese has melted evenly, and pushes it past the splitting point. Moderate heat, longer.
5. Use a starch to stabilise it.A roux base for a sauce, or a teaspoon of cornflour tossed with the grated cheese. Starch holds the emulsion together and makes it much more tolerant of heat.
6. Drain fresh mozzarella first.It holds a lot of water, which pools on a pizza and looks like the cheese has split. Tear it and drain on kitchen paper.
7. Avoid low-fat cheese for melting.Less fat means less to hold the emulsion, and it goes rubbery and stringy rather than smooth.
8. Rescue a split sauce with cold liquid.Off the heat, whisk in a splash of cold milk or cream, or use a stick blender.

Tips

• Mixing cheeses works well — a good melter for texture and a strong aged one for flavour gives you both.
• Pre-grated cheese is coated with anti-caking starch, which actually helps stability even though it melts slightly less smoothly.
• Bringing cheese to room temperature before melting reduces the heat needed and helps a great deal.

Questions people ask