"The grading is optical, as a result of experience, there being no linear or cubic measurement standard. Thus, a nice cluster with all berries of large size, would be a 'Six-Crown Cluster,' such being the very finest raisins on the stem. 'Five-Crown Clusters' were formerly the 'Dehesia' cluster, and 'Four-Crown Clusters' were formerly 'Fancy Clusters.' Grades less than 'Four-Crown' on the stems (the 'Three-Crown' and 'Two-Crown') are known as 'Layers,' or 'London Layers.' These are placed in boxes containing 20 pounds net; in half boxes of 10 pounds; and quarter boxes of 5 pounds; and in fancy boxes containing 2-1/2 pounds. Loose raisins, or raisins off the stem, are graded into Two-Crown, Three-Crown, and Four-Crown raisins by being run through screens the meshes of which are thirteen thirty-seconds, seventeen thirty-seconds, and twenty-two thirty-seconds of an inch in size, respectively. The Sultanina (erroneously called Thompson Seedless), and the Sultana are packed in 12-ounce cartons, 45 to the case."
"The invention of a raisin-seeding machine by George E. Pettit in the early seventies, and its use, has had a wonderful effect on the industry.
"Seeded raisins were first put on the market by the late Col. William Forsythe, of Fresno, Cal., who at first found it very difficult to dispose of 20 tons. The output in the last 15 years has increased from 700 tons to 50,000 tons per annum, and their popularity is constantly increasing. In 1900 about 14,000 tons were placed on the market, in 1905 about 21,000 tons, in 1910 about 31,000 tons, and in 1913 about 49,000 tons. The seeding machines in present use can turn out 300 tons per day. Seeded raisins are now the most important branch of the raisin industry.
"A brief outline of how seeded raisins are prepared will prove interesting. The raisins are first exposed to a dry temperature of 140° F. for three to five hours, after which they are put through a chilling process so that the pedicels can be easily removed, and are then thoroughly cleansed by being passed through cleaning machines. They are then taken by automatic carriers to another room, spread out on trays, and exposed to a moist temperature of 130° F. to bring them back to their normal condition. The raisins pass to the seeding machine, where they are carried between rubber-faced rollers and the impaling device of the seeding machine which catches the seeds and removes them from the fruits as they are flattened between the surfaces of the rollers. The impaled seeds are removed from the roller by a whisking device in such a way as to be caught in a separate receptacle. The seeded raisins pass through chutes to the packing tables on the floor below.