Put 2 or 3 small saucers in the freezer; they'll be used to quickly cool teaspoons of jam to find when the setting point has been reached.

Put 4 washed, rinsed and drained jars and lids on a baking tray and place in an oven at its lowest setting. Turn off the oven when the jars are hot, but leave them inside until you're ready to pot the finished jam.

Put all the ingredients in a large, deep and wide saucepan and stir well.

Switch on the heat to low and stir while the sugar slowly dissolves.

Once the sugar is completely dissolved, turn up the heat and bring contents to a boil – you can put a lid on for this stage to speed it up.

As soon as the jam has come to the boil, take the lid off and keep at a rolling boil until setting point is reached (15 - 25 min).

To test for setting point:

Take the saucepan off the heat.

Flake test: Take some jam on a wooden spoon, cool it a little, then let it fall off the edge of the spoon. If the final bits of jam come together into 'flakes' rather than running off in a stream then proceed to the Saucer test. If it doesn't flake, boil for another 4-5min then test again.

Saucer test: Take one of the cold saucers from the freezer, put a teaspoon of jam on it to cool then gently push the jam with your finger. If it wrinkles then setting point has been reached. If not, boil for another 4-5 min then test again.

Once setting point has been reached, take your jars from the oven and pack the jam into them. Protecting your hands, put the lids on and leave to cool.

When the jars are cold, tighten the lids a little more if possible. Label and store in a cool, dark place.

Ready to use immediately but unopened jars should keep at least a year.