54 BULLETIN 1141, U. S. DEPARTMENT OF AGRICULTURE. 



The treatment given the Silver prune, which is dried in a small 

 way in some sections, is identical with that of other prunes, with the 

 addition that the fruit is sulphured to preserve the color. The sul- 

 phur treatment is given after the fruit has been dipped and spread 

 on the trays. The fruit is left in the sulphuring chamber only 15 to 

 20 minutes and is then at once transferred to the drier. 



SMALL FRUITS. 



The small fruits are evaporated or dried to a limited extent only, 

 with the exception of the Logan blackberry, which is a commercial 

 factor in the fruit industry of the Pacific coast, and black raspberries, 

 which are dried on a more or less extensive scale, principally in 

 New York. Other small fruits, such as red raspberries, blackberries, 

 strawberries, and blueberries, and perhaps still others, are dried some- 

 times for home use, but they are rarely seen in the market. These 

 fruits may be dried by essentially the same methods as the more im- 

 portant ones above mentioned. These methods are briefly described 

 here. 



BLACK RASPBERRIES. 



In some sections, the kiln type of evaporator is largely used in dry- 

 ing raspberries. The ones built in recent years have been constructed 

 in general according to the plans described and illustrated in the first 

 part of this bulletin, but the older evaporators do not have the hop- 

 per above the furnace. Evaporators of the tunnel and other types are 

 also used, in which the fruit is handled on racks or trays with 

 galvanized- wire netting bottoms. 



Before the fruit is placed in the kiln, the floor is usually covered 

 with muslin, burlap, or some other kind of loosely woven fabric, 

 for the purpose of preventing the fruit from dropping through the 

 spaces between the strips of which the floor is made, or sometimes 

 galvanized-wire netting with -|-inch mesh is used instead of a fabric. 



As with all other fruits, raspberries for drying should be fully 

 ripe. Much of the fruit is harvested by batting — a method whereby 

 a wire hook is used to draw the canes into the desired position, allow- 

 ing them to be lightly beaten with a wooden paddle which knocks 

 the fruit into a device so arranged as to readily catch it as it drops. 

 An expert hand picker under favorable conditions will hardly aver- 

 age more than 125 quarts a day, while in harvesting by the batting 

 method 7^ or 8 bushels is a fair average. 



The manner of operating an evaporator in which raspberries are 

 being dried is substantially the same as when other fruits are being 

 handled. Where an evaporator of the kiln type is used, the fruit 

 is spread on the floor from 4 to 5 or 6 inches deep, depending largely 

 on the variety. Firm berries, such as the Ohio, can be placed con- 

 siderably deeper than the softer, more juicy sorts, such as the Farmer. 

 Where evaporators other than those of the kiln type are used the 

 raspberries are spread in a thin layer on the trays, a tray 3 by 4 feet 

 in size carrying about 11 or 12 quarts of fruit. The temperature 

 should be 135° to 140° F. at the outset of drying and may be increased 

 to 150° to 155° F. as the fruit becomes almost dry. 



As it begins to dry, the fruit passes through a soft stage, which, 

 however, lasts for only a comparatively short time. After this stage 



