Preserving pan

Three features, three jobs

Wide means a large surface area, and evaporation happens at the surface. Getting water out of the fruit is most of what making jam is, and a wide pan does it two or three times faster than a saucepan.

Sloped sides increase the surface further as the level drops, and they let the jam boil hard without climbing the walls and boiling over. Jam foams enormously and a straight-sided pan is a real hazard.

Shallow means the whole mass heats quickly and evenly, which reduces the risk of scorching at the base and gives you more control over when setting point arrives.

Material matters more here than usual

Stainless steel

The sensible default. Unreactive, durable, and heavy-based versions do not scorch.

Unlined copper

The traditional jam pan. Excellent heat conduction and it reacts with acidic fruit. Traditionally accepted for jam and not for chutney.

Aluminium

Reacts with acid. Avoid for anything with vinegar in it, which rules out chutneys and pickles.

Enamelled cast iron

Works, and it is heavy and slower to respond. Fine for chutney, less good for jam where timing is tight.

Non-stick

Not suitable. The temperatures reached at setting point are too high.

Base thickness

The one thing that decides whether your jam scorches. Thick, always.

If you do not have one

• Use the widest heavy pan you own. Width matters far more than the label on the pan.
• A large deep frying pan or a sauté pan works well for small batches.
• A heavy casserole works, and is deeper than ideal, so expect longer boiling.
• Never fill more than a third. Jam at a rolling boil rises dramatically, and boiling sugar burns badly.
• Make smaller batches. Two small batches in a normal pan beat one large one, and each sets faster.
• Not a stockpot. The shape is exactly wrong.
• Not aluminium for chutney. The vinegar will react.

Using one

1. Warm the sugar in a low oven before adding it. It dissolves faster, which shortens the pre-boil stage and keeps the flavour fresher.
2. Dissolve the sugar completely over a low heat before the pan ever boils. Undissolved sugar crystallises in the jar.
3. Then boil hard. A rolling boil that cannot be stirred down is what a preserving pan is designed for.
4. Watch it constantly at that stage. The gap between setting point and burnt is a couple of minutes.
5. Have frozen plates ready for the setting test before you start.
6. A knob of butter at the end disperses the scum and saves skimming.
7. Clean it while warm, with hot water. Set sugar comes off far more easily than cold set sugar.

Common questions