CALIFORNIA LYE-DIPPED RAISINS.
General Notes.
—In California the dipping of raisins in solutions of lye is yet in its very infancy, and I do not think that in the whole State over ten tons of lye-dipped raisins have been placed on the market yearly. But undoubtedly this process is destined to become of considerable importance, especially in localities where the drying of the first crop is accomplished with difficulty in the open air. The first and also most important condition in producing superior dipped raisins is that the grapes should be absolutely ripe. Unripe grapes will not produce any good raisins when dipped, but will turn reddish and otherwise become inferior.
Dipping Process.
—A good location for dipping raisins is by the side of an irrigation ditch, provided the water in the latter can be depended upon to flow constantly while the operation of dipping lasts. If not, the water must be procured by pumping or by means of pipes from reservoirs or water-works. Flowing water is of great importance in producing good dipped raisins, and is required for the perfect washing of the grapes. For this purpose, if no ditch is available, a large trough may be used to advantage, and so arranged that the water in it can be kept changing through a continuous flow. The following is a cheap and efficient arrangement for dipping in actual use in one of the largest raisin vineyards, and can be recommended on account of its cheapness and easy working: On one side of the trough is a stationary iron kettle with a fireplace underneath. By the trough is also placed an upright post, about five feet high, and on this balanced a horizontal beam with a double motion. It can be raised and lowered at either end, or swung to the left or right with ease. On one end of the beam is a hook on which to hang the grape bucket. On the other side of the trough is a rough assorting table. Two or more buckets are needed. These buckets are common galvanized-iron buckets, perforated thickly with holes, the latter not large enough to let any loose grapes through. In the kettle is kept constantly boiling a solution of water and potash. Soda is not suitable. The very best potash should be used in the proportion of about one pound to twelve gallons of water. The ripe grapes are now brought to the table and emptied in the buckets. A bucket is then hung on the beam, the latter swung and the bucket for a second lowered first in the pure water and then in the boiling potash; but it is immediately withdrawn and immersed in the water-trough. When rinsed for a few seconds, the grapes are taken out and spread on common raisin trays. If the weather is warm, the trays are stacked one on top of the other, and the grapes thus prepared are dried in the shade.
The rinsing of the fruit before drying is of great importance, and by far not sufficiently understood. In Valencia the finest raisins are treated that way and thoroughly rinsed before being dipped in the lye. But nowhere in Spain are the grapes rinsed in water afterwards, and it is yet an undecided question if this rinsing improves or injures the raisins. It is certain that the washing cleanses the berries, as the water in the kettle is sometimes dark and dirty; but if it is an advantage to deprive the berries of the lye which more or less sticks to them is very doubtful. It is well known here that lye-dipped raisins are apt to mold if the rains set in while the drying lasts, while we are told that in Spain the dipped raisins do not spoil even if subjected to several showers of rain. From this it will seem as if rinsing after dipping is not necessary or perhaps even injurious, but that, on the contrary, rinsing before dipping is of the utmost importance. It may be possible that the lye which adheres to the grapes will, in a great measure, prevent them from molding.
In Spain no olive oil is used for mixing in the lye, and it is not likely that the oil process will come in vogue in California until it is fully demonstrated that it not only greatly improves the grapes, but that it also enables the grower to realize a correspondingly better price for his raisins. Those who care to experiment with it cannot do better than to follow the practice as it is used in Smyrna, for a full account of which we beg to refer to the [article] under that heading. We might here only point out that the oil-dipped raisins of Smyrna bring many times the price of the lye-dipped raisins of Valencia. The arrangement of dipping, kettles, etc., may, of course, be greatly varied. Steam may be used for heating the lye and the rinsing water, if it is desired to keep the latter hot, and regular trays might be used to hold the grapes, instead of the buckets referred to above. Every grower will no doubt vary these appliances to suit his own fancy, and improve upon the methods of others. As an example of the devices used by another grower, we here reproduce the following from an essay on bleaching raisin grapes, compiled by the chief viticultural officer, and especially referring to the system used by Mr. Byron Jackson: “Mr. Jackson places the grapes on a tray made with a frame of iron, which is covered with wire gauze with a quarter-inch mesh. The frame projects upwards on the sides to prevent the fruit floating off while in the dip, and is made to receive, as a cover, the wooden tray on which the fruit goes to the dryer. When dipped and rinsed, the wooden tray is placed over the dipping tray, and two men transfer the fruit by turning over the two.”
The length of time required for dipping can only be ascertained by experience, and must differ with the strength of the lye, with the heat of the solution, and with the thickness of the skin of the grapes. Thus in different localities the strength of the lye and the length of immersion must always be different, and may even differ from year to year. When properly dipped, the skin of the grapes must show some very minute cracks, similar to cracks in glass which has been heated and suddenly immersed in or sprinkled with ice-cold water. Deep cracks are not desirable, as they will cause the juice of the pulp to leak out, after which the raisins will sugar. In Valencia the grapes used for dipping are the various varieties of Muscats, while in Smyrna both Muscats and Sultanas are used. Corinths are never dipped, as they dry readily and make superior raisins without this process.
Drying and Curing.
—After the grapes are dipped, they must be immediately dried either in the sun, or in sun and shade alternately, or entirely in the shade. According to the circumstances attending the drying of the grapes, the color of the raisins becomes more or less red or yellow, transparent or opaque. The most perfect amber color is attained in the shade, while in the sun the color rapidly changes to reddish, a less desirable color in dipped raisins. The more favorable is the weather for drying, the choicer will be the raisins, and the better their color. If the sun is very warm and the chances are otherwise favorable for drying, the trays should be exposed to the sun only long enough to have their dip thoroughly evaporated, and for this purpose one day in the sun may suffice. After this the stacking of the trays is advisable, and only occasionally may the trays be spread if the drying does not proceed rapidly enough. Such shade-dried dipped raisins will assume a beautiful amber-yellow color, and bring several cents more than those exposed to very warm sun. If, however, the weather is not very warm, the grapes must be dried in the sun, and the grower has then to be satisfied with the color that nature will give to his raisins. Dipped raisins do not necessarily require turning, as they generally dry well anyhow in from four to six days in fair weather. For this class of raisins dryers are very useful to help finish the drying. Such dryers must be almost air-tight, as sandstorms would invariably spoil the raisins, which, on account of their stickiness, are almost impossible to afterwards cleanse. Dipped raisins should always be dried on their trays, and on special drying grounds, which should be so constructed that no sand can blow on them, or at least so arranged that in case of rain the sand from the ground will not be splashed over the trays. In California we have at present no such drying-floors, but it will pay any one who intends dipping his grapes to construct them either of bricks, bituminous rock or lumber.
Stemming, Grading and Packing.
—Dipped raisins should be stemmed when well dried, and then graded in two grades. The proper receptacles for them are either sacks lined with paper, or twenty-pound boxes, in which they may be packed without fancy paper, or in the same way as prunes or other dried fruit. So far no uniform method of packing such raisins has been adopted in this State.
As to the usefulness and future of dipped raisins, not much can be said at present. Our importations of Valencia raisins, which are mostly dipped, are considerable, and as long as this class of cooking raisins is in demand, there is no good reason why we should not compete and endeavor to supply the demand. We can produce them as well as Spain can, and the only reason why we have not competed with Spain so far is that sun-dried raisins are so readily produced here, that it has not been to our advantage to produce anything else. There are, however, many places in our State which will grow Muscatel grapes of good quality, but with too thick skins to make them proper for sun-dried raisins. For all such localities the dipping process is to be recommended, as it will enable the growers to produce marketable raisins, and to profitably supply the demand for this variety of raisins now imported to this country from abroad. In localities with early and copious fall rains, the dipping process will enable the growers to finish quickly before the rains set in. California dipped second-crop Muscatels and Sultanas have brought as high as seven cents per pound wholesale.