Making homemade raisins start to finish. Normally, when I make raisins, I pick up a couple of cases at a time. I wash well in a mixture of water, vinegar, and salt. I prefer organic when i can get them. I cut a slit in each grape to decrease the dry time. it takes approximately 150 grapes to fill a tray without overcrowding. My dehydrator runs 24/7 for a few days to complete the task. I set my dehydrator to the high temp side of the fruit setting. I have a nine tray Excalibur dehydrator. It takes approximately two days for a full tray to dry. I spread the dried raisins out on parchment paper to cool completely, then store them in large mason jars. You can hear them ping as they fall into the jar showing they are dried completely. Do not vacuum seal raisins. You can breed botulism. Enjoy throughout the year.
This time I dried 4 cases of grapes. One I gave away, and the other three will be used for homemade gifts in a jar of oatmeal raisin cookies. Included is the recipe I have been using for years.