The Raisin Industry / A practical treatise on the raisin grapes, their history, culture and curing

by Gustavus A. Eisen

The taste of course is the most commonly used method for ascertaining the ripeness of the raisin grapes. Every grower experienced or not should examine his grapes repeatedly. To give directions for tasting the ripeness of the grapes is of course impossible; it must be learned, and can only be learned by practice. It is enough to say here that the grapes should taste very sweet, contain no acid, and if possible be rather solid.

The color is also a valuable adjunct in determining the ripeness of the raisin grapes. Fully ripe and perfect fruit should be amber yellow, somewhat transparent and waxy. If this color is combined with great sweetness, and in Muscatels with absence of acidity, we can be sure that the grapes are ripe. Some grapes do, however, especially when too much exposed to the sun, acquire the yellow amber tint without being sweet, but they are readily distinguished from the ripe grapes by their being of smaller size and harder, tasteless and acid. Such grapes never develop into good, mature grapes, and do not make good raisins. I may also remark that not all ripe grapes become amber colored. Those that grow in the shade and on very damp ground remain always green, although they acquire a certain sweetness, and will make good raisins. The Muscat grapes will make salable raisins even if not fully ripe, but in order to make superior and good raisins all grapes should be “dead” ripe, especially so if the grapes are to be dipped in lye. If unripe or partially ripe grapes of Muscats and Sultanas are dipped, they make very poor and red raisins; it would have been better-if they had never been dipped. This is especially the case with the Sultana, which begins to ripen and is eatable long before the Muscat, but which only makes a good dipped raisin after the Muscat has been ripe for some time. Three or four days make a great difference sometimes in the amount of sugar in the grapes, and consequently in the quality of the raisins, and the experienced grower will keep his grapes on the vines as long as possible to attain the greatest possible amount of sweetness. But on the other hand it takes judgment to foresee how sweet the grapes will be, as in unfavorable seasons they will not attain their full sweetness even if allowed to hang long on the vines. To know the time after which the grapes do not increase in sugar requires much experience and acquaintance with the locality where they are grown. In this respect different years vary very much.

Picking.

—Many vineyardists pick their raisins too green or before they are fully ripe. Not all raisins ripen at the same time, and to make the best possible raisins out of the grapes, it is necessary to pick over the vineyard several times, each time picking only the ripest grapes. In places where there are two crops of grapes, at least two pickings are absolutely necessary, and in many places two pickings are enough. The green grapes of the first crop are then left to be picked with the second crop, at which time they will probably be perfectly ripe and very choice. But if the vineyard is small and manageable, and the owner wishes to realize the most that he possibly can, he should make at least three different pickings, each time taking care only to pick those grapes which are fully ripe and which would make a first-class quality of raisins. As long as the smaller vineyardists sell their raisins in bulk at a contracted price of so much a pound for any kind or quality of raisins, we cannot expect any great improvement in the too common mode of picking, where good, bad and indifferent grapes go on the trays together. But I am certain that in a few years this will or must change. Raisins in sweatboxes will bring the price they are actually worth, and it will be to the interest of every grower to pick his grapes at the time they will make the best possible raisins, even if extra labor is required for the work. The pickers generally use small, pointed knives for separating the bunches, and they are preferable to small shears, as better enabling the picker to reach farther in between bunches and branches, and to cut the former without injuring the branch.

In picking the bunches, great care should be taken, much more than is at present in use. It is always best to begin picking in the poorest part of the vineyard, as it will take some time for the pickers to learn; they are almost certain to pick in the beginning too many green grapes. The poorest part of the vineyard is also apt to have the ripest grapes. The large, fine bunches should be handled with the utmost care, in order that the bloom of the grapes may not be injured. The bunches generally should be handled by the stems only, or, if this is impracticable, by the stem as much as possible. In separating a large bunch from the vine, the bunch should be cut as close to the stem as possible, and at the end of the stem of the bunch there should remain a portion of that broader part by which the bunch is attached to the main branch. There is nothing prettier on a bunch of raisins than this broad end of the bunch; it gives an idea of strength and oddity to the raisin cluster, showing the buyer at a glance that it is a cluster which was once solidly attached to the vine. Many raisin-packers place this broad end of the bunch so as to protrude above or between the berries, as if inviting the purchaser to take hold of it and thus lift the luscious bunch out of the box. With the poorer and smaller bunches, no such care in cutting need be exercised, and it would be to no benefit to so cut a small, poor bunch that it would cause the purchaser to believe it was a large bunch. Poorer bunches might therefore be cut with short stems. As to the handling of the bunches, the intelligent grower will soon learn how to instruct his men. If vine branches interfere with the lifting of the bunch from the vine, some of them may be cut without any injury to the vine, but too many branches cut this way will cause a new growth to start, which often is derived from the best fruit buds for the ensuing season, and which always is apt to be injured from frost.

A picker should average not less than fifty trays a day of cleaned and assorted grapes. At this rate the picking of twenty pounds of grapes costs about two and a half cents. Some persons employing white labor claimed to have lowered the cost of picking to one and three-quarter cents per tray of twenty pounds, but I failed to learn how these grapes had been handled, cleaned and assorted. The picking of the grapes is facilitated by previous care given the vines. Neglected and entangled vines are much more difficult and expensive to pick than those which have been properly cared for and correctly pruned the season before. The same may be said as regards vines between the branches of which weeds have been allowed to grow. In picking from such vines, the grapes are always torn, the best bunches destroyed and many grapes wasted on the ground.

Raisin Vineyard Truck.

Cleaning.

—When the bunch is picked or cut from the stem, it should be cleaned. If it is a first-class or even an ordinary layer bunch, every sunburnt berry, every leaf, twig or other conspicuous foreign substance, must be carefully removed with the picker’s right hand, while the left hand holds the bunch by the stem. This cleaning must some time be done, and at no time can it be performed with better results than when the grapes are green. The stems are then soft and flexible, while later on they are brittle, and in endeavoring to remove foreign substances many berries will be detached, or sometimes even the whole bunch broken. This cleaning of the bunch does not need to extend to third-rate or small bunches, which are to be used for loose raisins. The latter can be cleaned very rapidly with machinery, and it would only be a waste of time to clean them by hand-picking. The use of a pair of bellows is also very practical. With them much of the spider webs and smaller refuse can be removed, which could not be gotten rid of in any other way. A few hands should therefore go over all finer bunches and blow them clean, especially if sand or dust have accumulated on the trays or bunches. If the grapes are carefully assorted when picked, and the different grades placed on separate trays as they should be, this cleaning is done rapidly, as the largest part of the crop, which only will make loose raisins, need not be cleaned.