UNIVERSITY OF CALIFORNIA AGRICULTURAL EXPERIMENT STATION *»«%■ ■ m^m, **■ .«**•■#»..■*..-.. BENJ. IDE WHEELER, PRESIDENT COLLEGE OF AGRICULTURE THQMAS FQRSYTH hunt Deanano ,,_.„ BERKELEY H. E. VAN NORMAN, Vice-Director and Dean University Farm Schooi CIRCULAR No. 211 April,' 1919 SAVING RAISINS BY SULFURING By FKEDEKIC T. BIOLETTI and A. E. WAY An improved method of saving raisins in rainy weather has been tested at the Kearney Experiment Vineyard for three seasons, two of which were exceptionally wet, with encouraging results. It consists in sulfuring the raisins as soon as they are stacked after' rain. Its advantages are : 1. Even in the wettest and most unfavorable season yet experienced in Fresno it enables the grower to save his crop. 2. The cost of stacking is much reduced because: (a) It is not necessary to stack until it has actually rained. Even though the raisins are thoroughly wet they can be saved and the useless stacking that is forced by a threat of rain is avoided. (&) Stacking at night and in haste with the consequent payment of an excessive rate of wages is not necessary. A few hours or even two or three days may elapse before stacking without great harm. Molding does not commence for some time, especially if the weather is cold, and as soon as the raisins are sulfured they are safe, (c) The wet sulfured raisins may remain in the stack for many days without injury. It is not necessary, there- fore, to be in a hurry to unstack them. It is safe to wait a week or more if necessary until the weather is definitely settled. The Sulfuring Hood. — In order to apply this method, the grower must be furnished with a hood to cover the stacks and to confine the fumes of the burning sulfur until they have accomplished their object. The hood described here was made by Mr. A. E. Way, of the Viticul- tural Division, and Mr. W. A. MacCutcheon, Assistant Farm Advisor of Fresno. It is a modification of the hoods which have been used by Mr. Way successfully for three years. The lowest photograph in fig. 1 shows the completed hood and the others, the frame in process of construction. Fig. 2 shows the details of construction of this frame. The hood made from these specifications will cover about twenty- six trays in two stacks. It is light and easily handled by two men. This size was adopted as the most convenient under average conditions. If it were larger it would not only be more difficult to handle, and therefore more subject to injury, but it would necessitate carrying the trays a long distance in order to make a stack large enough to fill it. The hoods should be used in sets or outfits and four men are needed for each set. Two men first collect the trays and pile them in two stacks. The other two then carry a hood to these stacks, place it over them, and then place a pan with about half a pound of sulfur between Fig. 1. — Sulfuring hood in process of construction. Fig. 2. — Wooden frame of sulfuring hood. Material and Cost amber for frame: 2 pieces 1" X 3" 14' long... $ .30 2 pieces 1" X 3" 12' long... .25 2 pieces 1" X 3" 10' long... .22 2 pieces 1" X 2" 12' long... .15 27 cleats %" X %" 3' long .. .23 $1.15 Covering of frame: 26 ft. double-ply bldg. paper $ .42 Nails, 184 2%", 48 2", 162 1%" - 13 Labor : 2 men 2 hours at 40 cents.— 1.60 $2.15 Total $3.30 Specifications for Cutting the Material 2 pieces 1" X 3" 10', bottom strips, extending 2' for handles. piece 1" X 3" 12', cut 2 pieces 6' (top sides). piece 1" X 3" 14', cut 4 pieces 3' 414" (ends). piece 1" X 3" 14', cut 4 pieces 3' 3%" (end uprights). piece 1" X 3" 12', cut 4 pieces 2' 9%" (side uprights). piece 1" X 2" 12', cut 3 pieces 3' 6" (tops). piece 1" X 2" 12', cut 4 pieces 2' 9" (tops). 2 pieces building paper, 6' long X 3' wide (sides). 2 pieces building paper, 3' 6" long X 3' wide (ends). 2 pieces building paper, 3' 6" long X 3' wide (top). Cleats nailed along edges of paper. (1) (2) (3) (4) (5) (6) (7) the two stacks. They then light the sulfur and immediately shovel a little soil around the base of the hood to make it air tight. These operations take about three minutes, and by this time the sulfur has done its work under another hood. This hood is then removed and carried to another pair of stacks and the operations repeated. As it takes just about four minutes to assemble and stack twenty-six trays where the crop is of average size the operations are continuous and no time is lost. In making the two stacks they must be placed at exactly the proper distance apart, parallel to each other and vertical. Otherwise, time will be lost in moving stacks in order to put the hood in place, and there is danger of breaking the hood in placing it over crooked stacks. The correct placing of the stacks is much facilitated by using a guide. A suitable guide can be made from a 3-inch batten 12 feet long cut into one piece 6 feet 4 inches long, two pieces 18 eighteen inches long, and two pieces 1 foot 4 inches long. The long piece is placed on edge and the 18-inch pieces nailed to it at right angles six inches from each end. The shortest pieces are then used as braces to keep the guide square. 5' 4* i Fig. 3. — Guide for making stacks. Fig. 3 shows the method of stacking with this guide. The guide is placed on the ground where the stacks are to be made and a tray placed in each angle. Twelve or less trays are then placed on each of these bottom trays and the stacks when completed will be in exactly the correct position to be covered by the hood and to allow space between for the sulfur pan. The cost of the operations per ton can be estimated from the results of tests at the Kearney Experiment Vineyard, as follows : Stacking, sulfuring, and unstacking once $2.56 Sulfur, at $4 per 100 pounds 22 Amortization of cost of hoods, at 20 per cent 23 Total $3.01 The cost of the ordinary stacking per ton, based on results in 1918, is about as follows : Stacking once $ .80 Unstacking once 70 Stacking and unstacking, second time 1.40 Total $2.90 These estimates are based on a wage of $4 per day of eight hours and the use of eight hoods and four men for each outfit. The number of hoods necessary for each outfit depends on the time to which the grapes must be subjected to the sulfur fumes. With two hoods, this would be only five minutes ; with eight hoods, it would be thirty-five minutes. The time necessary has not been determined, but it is probably less than thirty-five minutes and more than five. As, in ordinary weather, the wet raisins would not commence to mold until after three days, a single outfit would be sufficient for a crop of about twenty-five tons or say twenty acres. The cost when the hoods were used would be about 3 per cent of the value of the crop, or about 50 per cent greater than two ordinary stackings. As they would make some stackings unnecessary, as they would avoid the necessity of paying panic wages, and as they would insure the saving of the crop, there would be a considerable net gain from their use.