Then place in a saucepan and mix well with lemon juice, ginger and preserving sugar, stir and bring to the boil. After a few minutes, chop up with the hand blender. Then let it simmer slowly, stirring well over and over again.
After about 15 to 20 minutes, use a small spoon to put some jam on a cool plate and make the jelly test. When the desired firmness is achieved, immediately pour jam into twist off lidded jars that have been rinsed with hot water. The edges of the glasses must be completely clean! Put a few drops of flammable alcohol on each of the glasses, ignite and screw the lid on immediately.