Dishwasher vs. Hand Washing

During this Thanksgiving holiday, I witnessed the dish washing behaviors of some of my family and friends. I noticed that both my father and mother-in-law pre-washed dishes before placing them in the dishwashing machine. Seeing this behavior made me wonder a few things:

1. Does pre-washing dishes really help?
2. Which one is better- Dishwasher or Hand Washing?


1. According to a New York Times article on the subject, pre-washing dishes is a "triple-bad" because it makes your dishwasher work less efficiently, and if you pre-wash with hot water you’re pumping precious water and electricity down the drain. Mike Edwards, a senior dishwasher design engineer at BSH Home Appliances in North Carolina explains, “Dishwasher detergent aggressively goes after food, and if you don’t have food soil in the unit, it attacks the glasses, and they get cloudy,” This process is known as etching and can cause permanent damage to eating utensils. So don't pre-wash your dishes!

2. For the answer to my second question, I went to the internet to find the facts! Treehugger.com featured an article about the subject, and according to a scientific study conducted at the University of Bonn in Germany dishwashers use only half the energy, one-sixth of the water, and less soap compared to hand washing. Yup, even the most sparing and careful washers could not beat the modern dishwasher. The study also rated the cleanliness achieved, again in favor of the washing machine.