A study in the journal Mindfulness found when done, well, mindfully, scrubbing dishes by hand can lift away stress along with the grease and grime on pots and plates. But what may be good for mental health may not be so great for the environment.

Washing dishes in the sink, rather than in a dishwasher, can waste huge amounts of water and energy, says Rainer Stamminger, a professor of appliance technology at the University of Bonn, in Germany.

While new Energy Star dishwashers use fewer than 5.5 gallons of water per load, handwashing dishes uses around the same amount and often more — between 5 gallons and more than 100 gallons per load, says Stamminger, who has studied handwashing dishes for 13 years.

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In a kitchen-like area in his lab, Stamminger has observed the dishwashing styles of hundreds of people from 28 countries. “There are huge variations,” he says. The most wasteful, which happens to be how many Americans do it, involves letting the hot water run continuously while slowly washing and rinsing every item under the faucet. (The typical faucet blasts two gallons of water a minute — or more, if you have an older tap.)

Squeaky clean and thrifty, too

Doing dishes by hand doesn’t have to be wasteful though. Stamminger has created a list of best practices for handwashing dishes and has done in-home studies showing consumers who follow this advice can cut by as much as half the amount of water and energy they use while still getting their dishes squeaky clean.

Here’s a step-by-step guide to washing dishes by hand while conserving water and energy. Before you start, wait until you have a full load.

1. Scrape your dishes. Use a knife or napkin to scrape excess food into the garbage or compost bin. You don’t want food residue to muck up your washing water, Stamminger says.

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2. Fill your sink. A sink with two basins is perfect for handwashing dishes. If you have a single basin sink you can use two plastic tubs. Fill one basin or tub halfway with water that’s as hot as you can stand. This is for washing. Fill the other halfway with cold water for rinsing. By filling up only halfway, you save water and leave room to soak some items while you wash others. The cold-water rinse saves energy.

3. Add dish soap to the hot water. Read the label for the manufacturer’s recommendation for how much soap to use. This can vary because some brands and formulas are concentrated while others are not, Stamminger explains. It also depends on what you’re washing. It takes less soap to get drinking glasses clean than it does to scrub pans used to cook fatty foods, he says. Why not add the soap at the same time you fill the tub or basin? Doing it after creates less suds. It might seem counterintuitive, but foam traps food particles and fat film in the washing water. “You do not need foam for cleaning,” Stamminger says.

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4. Wash the least dirty dishes first. Using a dishcloth, sponge or brush — your choice — wash the cleanest dishes first. Soak each item in the hot, soapy water and give it a good scrub. Then dunk each clean dish in the cold water to rinse. When you get to dirty pots and pans, you may need to use the rough side of sponge.

5. Refill if necessary. If while you’re washing you realize your hot water has gotten too soiled to clean more dishes, empty the sink or tub and start over with clean hot water and soap, Stamminger says.

6. Air dry your dishes. Place clean dishes in a dish rack or on a towel on your counter and let them air dry. Or use a clean kitchen towel to get them dry and put away more quickly.

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Allie Johnson is an award-winning freelance consumer writer with a degree in magazine journalism. She lives in Georgia with her husband and two dogs.