People who despise dishwashing chores and long for a dishwasher can take a guilt-free trip to their nearest electrical store. A new study shows that handwashing dishes wastes up to ten times more water and energy than an economy dishwasher.

Edie News Service reports that 75 volunteers from seven European countries were recruited by the German University of Bonn to wash up a typical family load of 140 pots and plates coated with hardened egg, spinach and margarine.

To the surprise of Professor Rainer Stamminger, author of the test study, handwashing was found to use between 20 and 345 litres of water, and 1 to 12 kWh. The average was 88 litres of water and 2.4kWh of energy, compared with a conventional European dishwasher that uses around 15 to 20 litres of water and 1kWh of electricity.

Professor Stamminger also observed a wide range of washing up methods. "Whether it be a housewife or a househusband, a German or a Pole, a Spaniard or a Turk, they all have different ways of doing the washing-up," he said. German and British test handwashers were more economical than their Spanish and Turkish counterparts, though the Spaniards produced the cleanest dishes. The performance of the Germans, who are supposed to be particularly clean, was no more than mediocre, adds Stamminger.

"We were able to characterise three entirely different types of [human] dishwasher," says Stamminger. The super-dishwasher attaches considerable importance to a good result, while the dishwashing economiser manages with as little water, energy and detergent as possible. The carefree dishwasher doesn't worry about the amount of water or energy used or the result.

The Professor's tips for environmentally friendly dishwashing by hand include preventing the food from hardening on the plates, soaking them prior to washing, and using a main hot water bath followed by a cold wash rinse.