River Cottage

Put the chopped apples into a pan with 100ml water and the lemon zest. Cook
gently until soft and fluffy, then either beat to a purée with a wooden spoon or rub
through a nylon sieve.

Put the butter, sugar, lemon juice and apple purée into a double boiler or heatproof
bowl over a pan of simmering water.

As soon as the butter has melted and the mixture is hot and glossy, pour in the eggs through a sieve, and whisk with a balloon whisk.

If the fruit purée is too hot when the beaten egg is added, the egg will ‘split’.

One way to guard against this is to check the temperature of the purée with a sugar
thermometer – it should be no higher than 55–60°C when the egg is added.

If your curd does split, take the pan off the heat and whisk vigorously until smooth.

Stir the mixture over a gentle heat, scraping down the sides of the bowl every few minutes, until thick and creamy.

This will take 9–10 minutes; the temperature should reach 82–84°C on a sugar thermometer.

Immediately pour into warm, sterilised jars and seal.

Use within 4 weeks. Once opened, keep in the fridge.

Variations

To make gooseberry curd, replace the apples with gooseberries. If you’d like to go for
a traditional, pure lemon curd, simply leave out the apples, increase the lemon juice
to 200ml (4–5 lemons) and add the grated zest of 2–3 lemons.