Is pre-grated cheese worse than grating it yourself?

The anti-caking agent is not a scandal — it is declared on the label and it is there for an obvious reason. But it is a starch coating on every shred, and starch coating changes how cheese behaves when it melts. Knowing which applications care makes this a straightforward decision rather than a matter of principle.

Step by step

1. Know what is on it.Usually potato starch, maize starch or powdered cellulose, sometimes with an anti-mould agent such as natamycin. All are declared in the ingredients. They stop the shreds welding into a block in the bag.
2. Understand what the coating does when heated.The starch absorbs moisture and gets between the shreds, so they do not flow into each other as readily. On a pizza that is barely noticeable. In a sauce it can leave a slightly grainy, floury texture and make the cheese less inclined to become smooth.
3. Use block cheese wherever the melt is the point.Cheese sauce, fondue, a proper cheese toastie, macaroni cheese, anything gratinéed where you want a molten sheet rather than distinct browned shreds. Grate it yourself and it melts as cheese should.
4. Use bagged where the shreds stay separate.Scattered over a chilli, a taco, a baked potato or a pizza, where the cheese browns in place rather than flowing. In those uses the coating changes almost nothing and the convenience is real.
5. Compare price per kilo, not per pack.Grated cheese is routinely a good deal more expensive per kilo than the same cheese in a block, and the bags are smaller than they look. Two minutes with a grater is usually the better trade.
6. Account for how fast it dries.Enormously increased surface area means bagged cheese dries and stales within a few days of opening, whereas a block keeps for weeks properly wrapped. Half a bag going hard in the fridge is a common and expensive waste.

Tips

• Grate a whole block at once and freeze it in a bag. Home-grated frozen cheese behaves better than bagged and costs less — toss it with a teaspoon of cornflour if you want it to stay loose.
• Cold cheese grates far more easily than room-temperature cheese. Fifteen minutes in the freezer makes a soft cheddar much less of a struggle.
• For a cheese sauce, tossing your own grated cheese in a little cornflour actually helps — it is the same principle as the bagged coating, but you control the quantity and add it off the heat.
• A food processor with a grating disc turns a kilo of cheese into shreds in under a minute and is worth getting out if you cook with cheese regularly.
• Bagged mozzarella for pizza is a legitimate exception. It is made low-moisture specifically for the job and behaves better on a pizza than fresh mozzarella does.

Common mistakes

• Using bagged cheese in a cheese sauce and blaming the recipe — The starch coating and the drier shreds work against a smooth emulsion. If your macaroni cheese is grainy and you used a bag, that is the first thing to change.
• Buying grated cheese to save money — It is almost always more expensive per kilo, and the shorter open life means more of it gets thrown away. It buys time, not money.
• Adding any grated cheese to a boiling sauce — Cheese proteins tighten and squeeze out fat above a simmer, giving a stringy, oily sauce. Off the heat, a handful at a time — this applies to block and bagged cheese equally.

Questions people ask