Because Sun-Maid is a grower-owned cooperative, our growers have a direct interest in producing the finest, premium-quality raisins in the world. The growing and harvesting of Sun-Maid raisins is a painstaking, year-round effort and one of the most labor intensive in agriculture. Vineyard tending and raisin harvesting are still accomplished almost entirely by hand, much the same way it was done a century ago.