RAISIN, the name given to the dried fruits of certain varieties of the grape vine, which grow principally in the warm climate of the Mediterranean coasts and in California and are comparatively rich in sugar. The use of dried grapes or raisins as food is of great antiquity (Num. vi. 3; I Sam. xxv. 18). "Raisins of the sun" are obtained by letting the fruit continue on the vines after it has come to maturity, where there is sufficient sunshine and heat in the autumn, till the clusters dry on the stalks. Another plan is partially to sever the stalk before the grapes are quite ripe, thus stopping the flow of the sap, and in that condition to leave them on the vines till they are sufficiently dry. The more usual process, however, is to cut off the fully ripe clusters and expose them, spread out, for several days to the rays of the sun, taking care that they are not injured by rain. In unfavourable weather they may be dried in a heated chamber, but are then inferior in quality. Some superior varieties are treated with very great care, retained on their stalks, and sent into the market as clusters for table use; but the greater part are separated from the stalks in the process of drying and the stalks winnowed out of the fruit.
Raisins from numerous Mediterranean localities are of three distinct varieties—(1) ordinary or large raisins, (2) sultana seedless raisins, and (3) currants or Corinthian raisins. (See CURRANT.) The greater proportion of the common large raisins of English commerce comes from the provinces of Malaga, Valen cia and Alicante in Spain ; these are known by the common name of Malaga raisins. Those of the finest quality, called Malaga clus ters, are prepared from a variety of muscatel grape, and pre served on the stalks for table use.
Sultana seedless raisins are the produce of a small variety of yellow grape, cultivated exclusively in the neighbourhood of Smyrna. The vines are grown on a soil of decomposed hippurite limestone, on sloping ground rising to a height of 400 ft. above the sea, and all attempts to cultivate sultanas in other raisin-growing localities have failed, the grapes quickly reverting to a seed-bearing character. The dried fruit has a fine golden-yellow colour, with a thin, delicate translucent skin and a sweet aromatic flavour.
Raisins are very successfully cultivated in California and in Australia. The United States is a large exporter. Practically all raisins grown in the United States are grown in the San Joaquin and Sacramento Valleys of California. The sultana seedless raisins of Smyrna are extensively grown under the name of Thompson seedless, which is rather an improved variety of sultana, and it is of these that the bulk of the United States ex ports to the United Kingdom consists. In Smyrna, owing to the climatic conditions, the sultanas are habitually soda-dipped, but in America this is not necessary and only those intended for English consumption are so treated. A second variety of raisins grown in California is the muscat, which is a seed-bearing variety, very sweet, and extensively used as a dessert fruit. It is also packed for household purposes by the removal of the seeds and by so processing them that they now pour from the box.