Energy Star, a joint program by the Environmental Protection Agency and the U.S. Department of Energy, cautions people to scrape, not rinse. Pre-rinsing dishes can waste up to 20 gallons of water.
Energy Star dishwashers and today’s detergents are designed to do the cleaning so you don’t have to pre-rinse.
And if your dirty dishes are going to sit overnight, use your dishwasher’s rinse feature. It uses a fraction of the water needed to hand rinse.
Speaking of a using a fraction of the water, a dishwasher built before 1994 wastes about 8 gallons of water per cycle compared to owning a new Energy Star-qualified model. So if you replace one of these old dishwashers with an Energy Star dishwasher, you’re saving enough water each week to wash two loads of laundry in an Energy Star qualified clothes washer.
So be lazy: scrape, don’t rinse!