1. Let every thing used for the purpose be delicately clean and dry; bottles especially so.
2. Never place a preserving-pan flat upon the fire, as this will render the preserve liable to burn to, as it is called; that is to say, to adhere closely to the metal, and then to burn; it should rest always on a trevet, or on the lowered bar of the kitchen range.
3. After the sugar is added to them, stir the preserves gently at first, and more quickly towards the end, without quitting them until they are done; this precaution will always prevent the chance of their being spoiled.
4. All preserves should be perfectly cleared from the scum as it rises.
5. Fruit which is to be preserved in syrup must first be blanched or boiled gently, until it is sufficiently softened to absorb the sugar; and a thin syrup must be poured on it at first, or it will shrivel instead of remaining plump, and becoming clear. Thus, if its weight of sugar is to be allowed, and boiled to a syrup with a pint of water to the pound, only half the weight must be taken at first, and this must not be boiled with the water more than fifteen or twenty minutes at the commencement of the process; a part of the remaining sugar must be added every time the syrup is reboiled, unless it should be otherwise directed in the receipt.
6. To preserve both the true flavour and the colour of fruit in jams and jellies, boil them rapidly until they are well reduced, before the sugar is added, and quickly afterwards, but do not allow them to become so much thickened that the sugar will not dissolve in them easily, and throw up its scum. In some seasons, the juice is so much richer than in others, that this effect takes place almost before one is aware of it; but the drop which adheres to the skimmer, when it is held up, will show the state it has reached.
7. Never use tin, iron, or pewter spoons, or skimmers for preserves, as they will convert the colour of red fruit into a dingy purple, and impart, besides, a very unpleasant flavour.
8. When cheap jams or jellies are required, make them at once with loaf-sugar, but use that which is well refined always, for preserves in general; it is a false economy, as we have elsewhere observed, to purchase an inferior kind, as there is great waste from it in the quantity of scum which it throws up, The best has been used for all the receipts given here.