Seedless grapes make the best raisins since they are soft and tender with no hard seeds inside. Green grapes make lighter-colored raisins, while purple and black grape varieties make the traditional dark-colored ones. Raisins are typically made by sun-drying grapes outdoors. Grapes dry best in areas with a week or more of hot, dry weather after harvest. It may take longer to dry them in areas with cool nights or overcast days.
Things You'll Need
- Blocks or sawhorses
- Storage container
Bring a pot of water to a full boil. Drop the grapes into the water, and boil them for 30 seconds. Remove them from the water and cool immediately in ice water. Boiling cracks the grape skins so moisture can escape during drying.
Place a drying screen outdoors in a sunny area. Set the screen on top of two large blocks or sawhorses so air can circulate freely around all sides of the screen.
Spread the grapes out on the screen in a single layer. Arrange them so they don't overlap or touch each other.
Leave the grapes outside during the day when the temperature is above 85 degrees Fahrenheit. Cover the grapes with cloth at night so moisture doesn't settle on top. Bring them indoors on days or nights when the temperature drops below 85 degrees Fahrenheit.
Stir the grapes once daily so all sides dry evenly and to prevent them from sticking to the screen. They require three to five days to dry.
Package the raisins into storage containers once they reach the desired dryness. Properly dried raisins feel leathery but are still pliable.
Tips & Warnings
- If the temperature is too low or the weather is wet, dry grapes indoors using a food dehydrator. Grapes require approximately 12 hours in the dehydrator to turn into raisins, but refer to the user's manual before using the dehydrator.
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