Preserves and Jellies
Gather fruit when it is dry. Long boiling hardens fruit. Pour boiling water over the sieves used, and wring out jelly-bags in hot water the moment you are to use them.
Do not squeeze while straining through jelly-bags. Let the pots and jars containing sweetmeats just made remain uncovered three days.
Lay brandy papers over the top, cover them tight, and seal them, or, what is best of all, soak a split bladder and tie it tight over them. In drying, it will shrink so as to be perfectly air-tight. Keep them in a dry, but not warm place.
A thick leathery mould helps to preserve fruit, but when mould appears in specks, the preserves must be scalded in a warm oven, or be set into hot water, which then must boil till the preserves are scalded. Always keep watch of preserves which are not sealed, especially in warm and damp weather. The only sure way to keep them without risk or care is to make them with enough sugar and seal them, or tie bladder covers over.
From The Ladies of Hyde Hall, Ann Low Cary Cooper Clarke’s Time (1819-1842)