Marmalades, Jams, and Fruit Pastes
Marmalades, Fruit Jams, and Pastes, are compositions of the pulpy matter of recent Fruits, or other vegetable substances, so combined into a mass with sugar, as will cause them to suffer as little alteration as possible in their native qualities. These comfitures are therefore in reality solid extracts of the pulpy matter of fruit conserved by means of sugar.
The evaporation of the mass is most conveniently performed in broad hollow vessels; the larger the surface of the vessel, the sooner will the aqueous parts exhale. When the pulpy matter begins to grow thick, great care is necessary to prevent its burning. This accident is almost unavoidable if the quantity be large, and the fire applied, as usual, under the pan; it may be effectually prevented, by pouring the mass, when it has acquired the consistence of syrup, into shallow earthen pans, and placing those in an oven with its door open, moderately heated; which, acting uniformly on every part of the liquid, will soon reduce it to any degree of consistence required. This may likewise be done, and more securely, by setting the evaporating vessels in boiling water; but the evaporation is in this way very tedious. The application of steam by means of what is called a preserving pan, is the best contrivance for preparing jams, fruit pastes, and all other culinary preparations, which are liable to become injured by a degree of heat exceeding that of boiling water.