Trim and wash the elderberries and put into a large saucepan with the water - just enough to barely cover the fruit.
Bring to the boil and simmer until tender. Strain through a scalded jelly-bag or at least four layers of muslin and allow to drip, without squeezing, until no more juice comes through. Add the lemon juice - juice of 1 lemon to 3/4 litre (1 1/3 pints approximately) elderberry juice. N.B. Do not leave the juice for longer than 1 day before finishing the jelly.
Measure the juice and allow 1 kg (2 1/4 lb approximately) Sure-Set to each 750 ml (1 1/3 pints approximately) for best results use 1 kg and 750 ml at a time. Heat the juice, add the Sure-Set and stir until dissolved, then bring to the boil and boil vigorously for 1 minute. (See 'Adding Sure-Set' for details on boiling and timing).
Pot and cover in the usual way; label and date. (See 'Potting and covering' for details).
Note: To make Elderberry and Apple Jelly, replace up to one third of the strained elderberry juice with apple juice.