Lumpy porridge

Why a lump seals itself

When a starch granule meets hot water it swells and gelatinises, turning sticky. If a clump of oats hits hot liquid together, the outer layer gelatinises immediately and forms a skin around the dry oats inside.

That skin is effectively waterproof. Stirring afterwards moves the lump about but does not open it, which is why lumps in porridge, gravy and custard are all so stubborn.

Everything that prevents it comes down to the same idea: let each grain meet the liquid separately, before the liquid is hot.

Making it smooth

1. Start with cold liquid. Put the oats and the cold milk or water in the pan together and stir before any heat is applied. This is the single most effective step.
2. Bring it up slowly over a medium heat, stirring as it goes.
3. Stir with a flat-ended wooden spoon or a spurtle rather than a round spoon — you want to sweep the base, where lumps start.
4. Keep it at a gentle simmer, not a boil. A hard boil makes it catch and spit.
5. If you must add oats to hot liquid, rain them in slowly from a height while stirring constantly, never all at once.
6. Take it off the heat slightly before it looks ready. It thickens considerably as it stands.
7. Salt it. Porridge without salt tastes of nothing, whatever else goes on top.

Fixing a lumpy pan

• Whisk it hard. A balloon whisk breaks up most lumps that a spoon will not.
• Add a splash more liquid and whisk again. Loosening it gives the whisk something to work with.
• Press lumps against the side of the pan with the back of the spoon.
• A stick blender, briefly, for a genuinely bad pan. It will make the porridge slightly gluey, which is a better outcome than lumps.
• Push it through a sieve if it is going to a child or a guest and appearances matter.
• Accept some texture. Steel-cut and pinhead oatmeal are meant to have body and are not supposed to be smooth.

By oat

Rolled or porridge oats

The standard. Five minutes, and the most prone to lumping if added to hot liquid.

Jumbo rolled oats

Chunkier and slower. Give them longer and expect more texture.

Pinhead or steel-cut

Twenty to thirty minutes, nutty and chewy. Soak overnight to shorten it.

Instant oats

Pre-cooked and very fine. Lump the most readily of all — always start cold.

Oatmeal

Ground, and closest to a gruel. Rain it in and whisk continuously.

Common questions