The manner of using the canvas is very simple. The canvas cover, which is stationary, is attached to the wire and the higher posts. Every evening the cover is thrown over the trays, the front or lower edge is hooked by the aid of the rings over the pegs in the ground, and the trays thus securely sheltered. In the morning, when the sun is up, the cover is thrown back over the higher posts, and the trays fully exposed. The trouble to cover is not very great; two men can cover forty tons of grapes in half an hour, and generally it is considered that the picking-gang can cover the whole crop in half an hour’s time every evening, and it takes them as long to uncover in the morning. If well cared for and properly dried, and stored away in the autumn after the crop is all in, this canvas cover, with its posts, will last six or seven years, and if painted or oiled would probably last still longer. One yard of canvas can cover thirty pounds of grapes, and for the purpose of utilizing the full space, the trays are made two and one-half by three feet.
Such is the process practiced in Orange county. If adopted elsewhere, it would enable many localities to produce good raisins, where the climatic conditions are such that no drying is now practicable. The process is not as good as the one employed in Malaga, but it has some advantages which make it very acceptable. It enables the grower to use trays, and it makes drying-floors unnecessary, and the spaces in the vineyard can be used without taking away room from the vines. On the other hand, the drying-floors of Malaga are warmer and more secure, and almost absolutely safe in case of rain.
Drying-floors.
—While, in some parts of California, the first crop dries generally without any difficulty, in other parts rain and dew very frequently interfere with the drying of even the first crop. In many places where raisin-curing is not successful, the same could be practiced profitably if we would adopt the system of drying-floors used in Spain. Even in localities where the first-crop raisins dry well, the second crop is always exposed to more or less rain, and the raisin-grower annually loses large sums of money on account of not being able to hasten the drying of the second crop. But it is doubtful if the Malaga drying-floors will ever be found practical and come into general use with us. They take considerable space from the vineyard, and are very expensive, but they are very secure, and when once built are very profitable. A limited number of such floors would be very useful in every vineyard, especially for drying the second crop. At present no such floors exist in this State. The following description gives an idea of how they may be constructed:
These drying-floors may be built of brick with the long sides as long as required, while the short sides should be about twelve feet long. The back wall is six feet high, while the front wall is only six inches high, which, with the above length of side wall, would give enough slope. In Malaga the interior is filled with black gravel and tamped hard, but for our purpose probably nothing would be superior to asphaltum, bituminous rock or cement. It must first be ascertained if bituminous rock would not impart a flavor to the grapes, in which case cement would be the most useful flooring. In order to allow the rain to run off, the front wall should be pierced with small holes close to the ground, but this would only be necessary in case the bed is filled with gravel, or no cement floor exists on top of it. Along the back part of the floor should be set a row of uprights of two by four lumber, driven securely in the ground. On the top of each post is set an eyelet, through which runs a stout wire along the whole back of the frame. A canvas cover long enough to reach the whole length of the floor should be used for covering, and, in order to secure it to the wire and the posts, it should be hemmed and furnished with small rings to run on the wire. In front similar rings are set in order that the canvas may be secured to the smaller posts and kept down in case of wind. On such floors common trays may be used. To make the canvas impervious to rain, it may be painted with boiled linseed oil. The above are only suggestions based on the Spanish drying-floors. For a full description of them, I beg to refer to the [article on Malaga]. In using linseed oil, care should be taken that only pure oil is used. There is linseed oil which contains chemicals which rapidly rot the canvas.
Dryers.
—The subject of dryers is of great importance to the California grower. The last few years have fully demonstrated that every raisin vineyard, no matter where it is situated, should have one or more dryers, in order that the last of the crop may be dried properly when the rain sets in. Many years these dryers are not required, but from time to time they prove of vast value, and if properly constructed are much superior to any drying-floor. But so far no perfect dryer has ever been constructed. Most dryers are too expensive, costing from three thousand to seven thousand dollars, when of a capacity to dry from twenty-five to fifty tons of green grapes at one charge. Nearly all late dryers are constructed with a fan, which sucks the air out through one end of the building. The large complicated dryers are all patented, but there can be no doubt that good small dryers might be constructed by every grower, which will do good service. As, however, so far no very perfect dryers have ever been constructed, and as every owner of one changes and rebuilds every year, we must leave the consideration of the construction of these dryers to some future time when more knowledge or experience will have been gained. Dryers large enough to hold a charge of one ton of green fruit have been constructed at the price of two hundred dollars by Ellwood Cooper of Santa Barbara. They dried their fruit in twenty-four hours, but they were never used for raisins.
But as this style of dryer may be adapted to raisins, I will give a few hints at its construction. The heating apparatus consists of a large iron drum, or radiator, seventeen and one-half feet long by two and one-half feet wide, set on a furnace in which is burned wood. The furnace and radiator are built into a bank, on top of which the dryer is built. This dryer is simply a large wooden box about seventeen feet square and six feet high, and looks, as seen from the outside, like a chest full of drawers. These slide on frames, are deeper than they are broad, and contain movable bottoms or trays made of small redwood ribs. They begin about two feet from the top of the radiator; if closer, the heat would be too strong for the fruit. The ventilation is had by small sliding doors at the bottom of the chest, through which the air rushes in, while it goes out through the drawers, which for this purpose are left open an inch or two. The chest is covered over with an open shed, which makes the labor pleasant, and enables the attendant to inspect any drawer at any time without seriously disturbing the heat of the dryer. The cheapness and effectiveness of such small dryers are such that every one can afford them. A dozen such small dryers all set in a row in a bank could be attended to by very few hands. They would also be preferable to very large dryers on account of the short time required to fill them, and their raisins can be dried long before a larger dryer has been filled.
As to the usefulness of steam or fire dryers there can be no doubt. The idea is not to entirely dry the raisins in them, but only to finish up the raisins when, on account of unfavorable climatic conditions, they do not dry any more out-of-doors. The question as to which are best, “machine-dried” raisins or those dried in the sun, is entirely unimportant. No one would think of drying raisins entirely in the dryer, as it would not pay. Raisins properly finished in the dryer are not inferior to those entirely sun-dried.