to 1 lb. of sugar for each lb. of fruit is the usual amount, but ½ a lb. is sometimes enough to preserve the fruit, and if this quantity is sufficient no more should be used, as jam is often unpleasantly sweet with very little flavour of the fruit left. The methods employed vary considerably; sometimes the fruit is boiled a long time and slowly, and the sugar added towards the end of the process; but more frequently the sugar is boiled first with a little water, and the fruit added afterwards and boiled from 20 to 60 minutes.
The latter method is commonly employed in manufactories where time is money, and it certainly preserves the shape, colour, and flavour of the fruit better than the former, which, however, has advantages for some fruits that require long stewing, and for those persons who find it difficult with the means at their disposal to make the jam boil as thoroughly and completely as it readily does in the manufacturer's pans, heated by steam coil or gas to the exact temperature required.
The pots in which the jam is put must be perfectly dry and the cupboard in which they stand neither so warm that the jam ferments, nor damp so that it becomes mouldy. The housekeeper will do well to remember that mould is a plant sowing itself by multitudes of seeds, so small that they penetrate the tiniest crack. It spreads, therefore, readily from one thing to another, and may sometimes lurk unsuspected on the shelves of a cupboard that is not well cleansed and aired. Formerly jam was allowed to become quite cold before being covered, under the erroneous belief that the steam arising from it would, if confined, produce mould. Now jams, jellies, and marmalades of every description are covered as speedily as possible, before the escaping steam loses its power to exclude the air. If air is allowed to enter it may carry with it bacteria which quickly develop into mould, more particularly so when the preserved substances happen to be stored in a warm damp place favourable to the growth of such organisms.
Fruit jellies are compounds of the juice of fruit and sugar, concentrated by boiling to such a consistency that the liquid upon cooling assumes the form of a jelly. But notwithstanding the resemblance in appearance and in name, this jelly, which is known as pectin, is from a chemical and nutritive standpoint entirely different from gelatine. It is closely allied to gum, and has about the same food value as the sugar with which it is boiled.
Candied or Glace and Crystallized Fruits.—Before fruit can be subjected to the final processes by which it is preserved for use in these two forms, it must first be boiled in syrup. The fruit to be candied or iced is dried before the fire or in a cool oven, the syrup in which it was cooked being meanwhile boiled to the "large blow" degree (see p. 1070). When the syrup has cooled a little, the fruit should be dipped into it until thoroughly coated, and then dried, when they will have a transparent coating. Fruit to be crystallized should, immediately on its removal from the syrup, be rolled in crushed loaf sugar and after-