I always pre-rinse my dishes before I put them in the dishwasher, but I wonder if this is wasting water. Can I stop pre-rinsing the dishes, and will it really save that much water?
-Diana C., Indian Harbor, FL
Unless your dishwasher is more than a decade old, pre-rinsing your dishes does waste water. Modern dishwashers are well-equipped to handle reasonable amounts of food residue, and scraping off the excess food (especially any solid particles like bones or meat) should be sufficient. Consumer Reports notes that most of the models it tests make quick work of even the tougher residues. It helps that many models use features like soil sensors and strategic dish rack design to improve cleaning power, even while reducing energy and water use.
Skipping the pre-rinsing can drastically reduce the amount of water used to get dishes clean. “Rinsing dishes can use up to 20 gallons of water before the dishes are even loaded,” according to ENERGY STAR, and “Hand washing your dishes costs $431 more in energy and water” than using an ENERGY STAR certified dishwasher. Why add the resource costs of hand washing on top of the comparatively low resource consumption of a dishwasher?