The first step to producing good raisins is growing quality grapes in the vineyards. Grape farming is a year-round commitment and includes the practices of pruning, irrigation, fertilization, and pest control. Most of the work done in these vineyards is still done by hand. Pruning involves the removal of parts of the vine to control its growth pattern. This has the benefits of equalizing the quality of grape throughout the vineyard, making other farming tasks easier and reducing costs. It is typically done when the vines are dormant between August and October. Irrigation is done during the summer while the vines are growing to keep a continuous supply of water in the vineyard soil. While fertilizers are not needed in all vineyards, some vines respond well to the use of nitrogen and zinc based fertilizers. Fertilization is typically done during the summer growing season.
Vineyards are susceptible to various diseases and insect attacks, so it is important for these factors to be controlled. Chemical and biological agents are used to control mites and other insects. Sulfur dusting is used to prevent the growth of mildew and other fungi. Since these compounds can have an effect on the overall grape quality, attempts are made to minimize the amounts used.
Harvesting and Drying
Starting in late December and continuing through April, the grapes are harvested. At this point in the year they are at their optimum sweetness. Bunches of grapes are handpicked by field workers and dippped in potatium carbonate solution dried on tray and then spray of dehydration oil is applied. Further dried raisins are sent for cleaning, neating, grading, sorting, and packing process.