Step 1: To start:
The Boots Book of Home Wine Making & Brewing (New and revised edition 1978) Recipe 119 PLUM (dry)
42 red/black plums (4.5lb in the book, but I have no scales)
245g red grape juice concentrate (1/2 pint in the book)
1 Kg white sugar (2lb in the book)
1 tsp citric acid (juice of a lemon would be fine instead)
1 cup of strong tea (1/2 tsp of tannin in the book)
1 tsp pectolase
1 tsp yeast nutrient (ammonium phosphate & sulphate)
1 tsp Super Wine Yeast Compound (i.e. yeast and nutrient as above, which in retrospect I didn't need...)
A 5 gallon / 25 litre bucket, with snap-on lid.
Electric blender (optional)
A long spoon
Two 1 gallon / 5 litre demis
1 fermentation lock
Step 2: Plums: preparation
Add plums to a food-grade bucket, and cover with boiling water (~ 5 pints or ~3 litres). This cleans, sterilises and softens the fruit. When cooled pour off the water.
Wash your hands and squeeze out the stones, this will leave you with plum-mush and sticky-fingers.
Step 3: Before fermentation:
Add 1 cup of strong tea (of the "English Breakfast" type, no milk, no Earl Gray) otherwise tannin if you have some.
Add 1 tsp of citric acid, or the juice of a lemon (as opposed to bottled lemon juice)
Add 1 tsp pectolase. This should 'digest' pectin within the fruit, which will otherwise give a hazy finish to the wine.
And finally, the book recomments 1 Campden tablet.
In water, these produce sulphur dioxide to sterilise.
Put the lid on the bucket and leave overnight.