At some point in your life, you were probably told that hot water cleans better than cold water when you’re using the dishwasher or washing machine. We’re here to tell you that’s not the case.
According to a senior scientist for sustainability at Seventh Generation (a cleaning company), hot water was useful years and years ago because it “sped up the cleaning process when detergents and machines were less efficient.” Nowadays, detergents have been formulated to be effective even in cold water. They no longer need to be “activated” with hot water, as earlier versions did, and contain enzymes that “literally cut up the soils and allow the surfactants to move the stains off the clothing.”
Cold water has additional benefits. It doesn’t fix stains in place the way hot water does, meaning you can actually get cleaner-looking clothes as a result; and it is gentler on fabrics, increasing their longevity. Not to mention turning down the heat on the washing machine and dishwasher can save you a boatload of energy. When it comes to laundry, three-quarters of emissions associated with a single load comes from heating the water itself, so a small tweak practiced over time can go a long way toward reducing your household’s impact.