Pick over the fruit, discarding those with damaged flesh or any trace of mould. Wash and drain. Remove the stones, using either a cherry stoner or a small knife, the weight is calculated after stoning.
Pre-cook by simmering the fruit in a large saucepan with 150 ml / 1/4 pint of water for 5-10 minutes or until tender. Add the Sure-Set and heat slowly, stirring, until dissolved, then bring to the boil and boil vigorously for 4 minutes. Start timing from the moment when the mixture begins to bubble vigorously. Remove scum if necessary.
Cool for a few minutes then stir to distribute the fruit.
Pot and cover in the usual way; label and date. (See 'Potting and covering' for details).
N.B. Varieties of cherries, other than Morello, require the juice of one lemon added at the same time as the Siúcra Sure-Set Sugar.