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

by Gustavus A. Eisen

—In using this method, the top layer is finished first, and the bottom last. The packing is done as follows: In the bottom of a tin or galvanized-iron tray, previously described, is placed one of White’s facing-plates. As will be remembered, the frame has a loose drop-bottom, which falls out as soon as the tray is turned over. The facing-plate is placed either directly on this loose bottom, or on the flange supporting it, and always with the facing-cups upward. The facer now places loose selected raisins, one in each hollow, presses his finger on the raisin and works it in the hollow until it becomes flattened. When all the cavities are filled, loose raisins are carefully filled in until the tray is full, when but a gentle pressure is required to steady the raisins and make them keep their places. In the meantime, fifteen pounds of raisins have been put in twenty-pound boxes and gently pressed. Some packers of choice raisins use a wrapper and label for every layer of five pounds, which greatly improves the general appearance of the box. After all is ready, a loose zinc plate is placed over the filled frame or tray, the latter is reversed and placed directly over the raisin box, in which has already been placed the required paper wrapper. The zinc plate, which only served to steady the raisins while the frame was being turned, is now quickly withdrawn, and the five-pound faced layer falls down in the box entirely undisturbed, kept so by the facing-plate which here acted as follower. The box is now ready for nailing, after a label and wax paper have first been placed on top of the plate. Without the facing-plate, a skilled facer can face some forty boxes a day, while from twenty to thirty boxes is a low average. With the facing-plate, the facing can be accomplished with more speed and accuracy.

Comparative Value of the Two Methods.

—The top-up method has several disadvantages. It requires a heavy pressure of the raisins to create a smooth, flat surface on which to face. But even if no facing is done, the top layer will always be more or less uneven, and requires heavy pressure to make it smooth, and appear well and to advantage. This heavy pressure always bursts many of the raisins, and causes them to sugar and spoil. It has also another disadvantage, that the facing of the top layer can only be done with the fancy paper previously placed in the box. In facing and manipulating the raisins, this paper becomes more or less soiled and wet. In using the top-down method, the paper is placed in the box at the last moment, just before the final five-pound layer is emptied from the tray upon the fifteen-pound layer below. I consider these advantages so essential that I must strongly indorse the top-down method, and I believe that, in course of time, it will be generally adopted by all packers who care for the keeping qualities of their raisins. As to the time and expense required by these two methods, there is but very little difference. The top-down method is possibly a little slower and more expensive, but it is by far the better, and the difference in expense of packing is not great enough to be taken into consideration.

LAYER RAISINS.

Sweating or Equalizing.

—This is a process by which the overdried raisins are made to attract sufficient moisture from the underdried raisins in the same box or bunch, and whereby the overdried raisins are made moister, while the underdried ones become drier. Equalizing also moistens the stems sufficiently to prevent them from breaking when being handled. In our California climate, where the air is so dry, this equalizing process is an absolute necessity, and no first-class raisin pack can be produced without the raisins having first been equalized. The word “equalizing” is to be preferred to “sweating,” as the latter word may be misunderstood as meaning that a certain amount of heat is developed by storing the raisins. Heat is indeed necessary, but it should come from the outside air, not from the inside or from the raisins. If from the latter the raisins will be in a fair way to become spoiled. In the foregoing I have described the construction and workings of the sweathouse. It may be suggested that, if there is no sweathouse on the vineyard, a large sail or canvas may be used as a substitute. The latter is simply thrown over the boxes where they are piled out-of-doors, and answers to some degree in keeping the raisins moist. But as this is only a substitute, I shall not dwell longer on its usefulness. It may, however, be said in favor of this appliance, that it is used by one of our largest packers, and by him considered as of equal value if not superior even to a regularly constructed equalizing house.

The raisins which are to be sweated are only the clusters or layers, and not the loose, which as we have seen should at once be taken from the field to the stemmer, while the stems are yet crisp and dry. It is therefore of importance that the bunches or layers should be separated from the loose already in the field, or, which is much preferable, before they are dried, at the time when they are picked from the vines. If the latter is done properly, there will be only a small quantity of loose which will go in the sweating-house with the layers. The layers should at any rate be placed at once in sweatboxes when taken from the trays, and between every two layers of bunches there should be a stout sheet of manilla paper, in order that the bunches may not become mixed. When taken to the sweathouse the boxes should be so placed that air can enter every one. It will not do to place one box on top of another so as to cover up the top entirely, as the raisins are then apt to ferment in a very short time, and, before the raisin-packer is aware, whole piles may be absolutely spoiled. It is not necessary to place the boxes crosswise, as it is enough to allow the short side of each box to overlap the underlying box a little; sufficient air will then enter. In very dry weather the floor of the sweathouse may be sprinkled with water, but this is generally not needed, as the underdried raisins will give out moisture enough to soften those that are too dry, as well as the stems. Every day the sweathouse should be aired, and it is a mistake to believe that all air should be excluded. If air is not daily admitted, the raisins will mold and spoil, and it is even advisable to keep a circulation of air constantly through the house during the daytime. The attentive packer will soon learn to regulate this, and nothing but actual experience with his particular sweathouse will enable him to decide how much air should be let in and to what extent the doors should be closed.

At the end of from ten days to three weeks, the equalizing process should be over, and the layers ready for further packing. When the boxes are removed, it will be found that the majority of those raisins which had been too moist or underdried have dried sufficiently, while on the contrary the overdried raisins, as well as the formerly brittle stems, will have acquired sufficient moisture to enable the packer to manipulate them without risk of breaking the bunches. The raisins should be pliable, and stand moderate pressure without cracking or breaking. But while equalizing is an important operation, and one which we cannot dispense with, it is always to the grower’s interest to so dry his raisins previously that they will require as little equalizing as possible, as even the most carefully sweated raisins which have once been overdried will never afterwards equal those which were at once properly dried in the field. The overdried raisins will always have a tougher skin and be inferior in color; but on the other hand they will keep better than raisins which have been dried less.

Grading and Weighing.

—The next step after the raisins have been equalized is to remove them to the grading tables. This should not be done by dumping the contents of a sweatbox on the table, as in this way but very few of the real choice bunches are saved for the packer. If, however, the raisins have been placed carelessly in the boxes, without sufficient or perhaps without any manilla papers between the layers, the only way is to dump out the contents. By first placing the sweatbox on the long side, and then turning it over, the raisins are but slightly disturbed. But to get these out afterwards from the chunk is the great difficulty, and many bunches must necessarily be broken. If, again, the raisins have been carefully handled and consigned to the sweatboxes, with four papers in every box, not counting in the top cover, the care and handling of the sweatboxes will be much simplified. The sweatbox is then placed alongside of the grading table, and each layer with its paper is lifted out carefully, and placed on the table. The assorting is now to begin. The bunches are taken up one by one, all inferior berries are clipped out, all soft ones are separated and placed in a box by themselves to be further dried. As each bunch is examined and cleaned, it is put in one of the weighing trays resting on small scales at either end of the table, and, when the scales indicate that five pounds of raisins are in the tray, the latter is removed to the packing table.