Seedless grapes
Large tray for baking
Large pan for boiling water

Preheat oven to 160 degrees. Wash the grapes and put them into boiling water until skins crack. Remove the grapes and spread them in a single layer on the large tray. Place the tray in the oven for 2 to 3 hours, turning grapes at least twice. When the grapes are dry and pliable, remove them from the oven and cool. Store any uneaten raisins into an air tight glass container.