Ingredient

Cranberry

Cranberries are hard, dense, intensely sour berries with air pockets inside — which is why they bounce, why they float in the bogs they are harvested from, and why they burst audibly in a hot pan. They are almost never eaten raw and they set into a sauce with nothing added but sugar.

A fruit with air in it

Each cranberry has four small internal air chambers. Growers use this: the bogs are flooded at harvest, the fruit floats free of the vines, and it is corralled on the surface. The same chambers are why a fresh cranberry bounces when dropped, which is a genuine commercial grading test rather than a piece of folklore.

In a pan, those chambers expand and the berry bursts with a pop. Once the popping stops, the fruit is cooked, and there is no need to guess.

Raw, they are extremely sour and quite astringent. This is one of the few fruits where cooking is not a choice.

Why cranberry sauce sets by itself

It is the easiest set in the kitchen and most people never think about why.

Very high pectin

Cranberries carry a lot, concentrated in the skins.

Very high acid

Which is the condition pectin needs to gel. Nothing has to be added.

So it needs only sugar and water

Fruit, sugar, a splash of water, twelve minutes. It thickens as it cools, so a sauce that looks thin in the pan will be right in the bowl.

Overcooking makes it stiff

Past the point where all the berries have burst, it moves towards a solid jelly. Take it off when the popping stops.

It keeps

Because of the acid and sugar, a jar of cranberry sauce lasts well in the fridge — though keeping times are a food-safety question and the Food Standards Agency is the authority on them.

Beyond the Christmas bowl

• With a strip of orange zest and a cinnamon stick, which is the standard improvement and a real one.
• A splash of port, or of red wine vinegar, added off the heat, which gives the sauce some depth.
• In a bread sauce or a stuffing, where the acidity lifts a heavy mixture.
• Cranberry and apple crumble, where the apple supplies bulk and sweetness and the cranberry supplies sharpness.
• In a relish, raw and blitzed, with orange, sugar and a little onion — the American style, and it is sharper and fresher than the cooked kind.
• Dried, in baking or a grain salad, where they behave like a sour raisin.
• Frozen and kept. They freeze without any preparation at all and last a year, so a December glut is a year-round ingredient.

Making the sauce

Twelve minutes, four ingredients.

1. Rinse the cranberries and pick out any soft or shrivelled ones.
2. Put them in a pan with sugar and a small splash of water — much less water than seems right, because the fruit releases plenty.
3. Add a wide strip of orange zest if you want it. Cinnamon, star anise or a bay leaf all work.
4. Bring to a simmer and cook until the berries have burst and the popping has stopped, stirring now and then.
5. Taste and adjust the sugar. Cranberries vary and the sauce should stay sharp.
6. Cool completely before judging the set. It thickens considerably as it goes cold.

Common questions