Hull and wash the strawberries and drain well
Put into a preserving pan or a large thick-based saucepan and crush.
Add the lemon juice or the citric acid or either of the fruit juices and allow to cook gently to soften the fruit, about 10 minutes.
Add the sugar and stir over a gentle heat until it is dissolved.
Bring to the boil and boil rapidly, to setting point, about 15 minutes.
Pot and cover in the usual way; label and date. (See 'Potting and covering' for details).