How To: Keep your pumpkin fresh for weeks this Halloween. After you scoop out and carve your pumpkin, dip it in a large container of Bleach & water (use 1 tsp: 1 gal. mix) The bleach will kill the bacteria & help your pumpkin stay fresh longer. Once completely dry, (Drain upside down) add 2 tbs. White Vinegar and 1 tsp. lemon juice to 1 quart of water. Brush this solution onto your pumpkin to keep it looking fresh for weeks.