Put the sugar into a preserving pan or large saucepan with the vinegar and leave to dissolve over a low heat. Tie the lemon zest, cloves, allspice, ginger and cinnamon in a muslin bag and add to the pan. Peel peaches, cut in half and remove stones. Put the prepared peaches into a weak salt and water solution to prevent them from browning. When they are all prepared, rinse in cold water and add to the pan. Cover and simmer gently for 20–30 minutes until tender. Do not cook too quickly or the peaches will break up. When the peaches are tender, remove carefully with a draining spoon and arrange neatly in jars. Boil the liquid rapidly for about 5 minutes until it is the consistency of thin syrup. Pour over the peaches while still hot. Cover and leave to mature for at least 3 months before using.