Stockpot

Surface area decides evaporation

Liquid evaporates from its surface. A wide shallow pan has a large surface for its volume and loses water fast; a tall narrow one has a small surface and loses it slowly.

A stock wants to sit at a bare simmer for hours while collagen converts, and it does not want to reduce by half in the process. A tall pot keeps the volume roughly stable and lets you cook for as long as the bones need.

The same shape helps in another way: bones and vegetables can be fully submerged in a tall pot without needing an enormous quantity of water, which keeps the stock concentrated.

When the shape is right and when it is wrong

Stock and broth

Right. Long simmering with minimal reduction.

Boiling pasta or potatoes

Right. A lot of water, brought to the boil and kept there.

Blanching

Right, and the volume matters — a large body of water barely drops in temperature when food goes in.

Preserving and jam

Wrong. Jam needs fast evaporation and a wide pan. A stockpot makes setting take twice as long.

Reducing a sauce

Wrong, for the same reason. Move it to a wide pan.

Braising and stewing

Usually wrong. A heavy wide casserole browns better and fits a joint.

Deep-frying

Possible and awkward. A tall pot is safer for oil volume and harder to manage food in.

Choosing one

• Size: eight to twelve litres covers most households. Bigger is only useful if you make stock in quantity or cook for crowds.
• Base: a thick sandwiched base stops the bottom scorching during a long simmer. Thin bases catch.
• Material: stainless steel is the sensible default. Aluminium reacts with acidic contents; unlined copper likewise.
• Handles: two, riveted, large enough to grip with oven gloves. A full stockpot is genuinely heavy.
• Lid: worth having, and a stock is usually simmered uncovered or barely covered.
• A pasta insert or a steamer basket turns one pot into three, and is the reason many households own only this one large pan.

Getting the most out of it

1. Start stock with cold water and bring it up slowly, so proteins coagulate gradually and can be skimmed.
2. Skim in the first twenty minutes, before the aromatics go in.
3. Keep it at a bare simmer. A tall pot on a small burner tends to boil at the base while the top looks still — watch it rather than trusting it.
4. Do not fill it more than three quarters, particularly for pasta, which foams.
5. Use a heat diffuser if the pot is much wider than the burner.
6. Strain by ladling rather than pouring a full heavy pot.
7. Cool stock quickly and safely — decant into shallow containers rather than leaving a full pot to cool. How to cool and store it is a Food Standards Agency matter.

Common questions