How are raisins preserved?

Raisins are preserved by drying grapes, which removes their moisture content and inhibits the growth of bacteria and molds. This process can be done through sun drying, air drying, or using dehydrators and ovens. The lack of moisture helps to extend their shelf life while concentrating their natural sugars and flavors. Additionally, some raisins may be treated with preservatives like sulfur dioxide to maintain color and prevent spoilage.