Should you wash clothes in hot water?

Consumer Reports says—No!

Washers have changed. Detergents have changed. You can save energy washing in cold water. And it gets the job done just the same.

As the Department of Energy changed the standards to be more eco-friendly, manufacturers lowered wash temperatures while maintaining effectiveness.

And detergent companies responded. They added enzymes that remove dirt and stains at lower water temperatures. Most quality detergents now are less effective in hot water.

Today, “detergents are formulated with enzymes that kick into action even at 60 degrees Fahrenheit,” says Pat Slaven, a chemical engineer who worked as a detergent tester for Consumer Reports for 10 years.

Interestingly, if you’re trying to remove a stain, cold water is still the better option. Once water temperatures exceed 75 degrees Fahrenheit, today’s detergents become less effective. In fact, the heat actually causes the stain to seep deeper into the fabric.

Washing in hot water also runs the risk that clothes shrink, fade, or get damaged. In general, hot water is hard on fabrics and reduces their lifespan. Washing in cold water reduces the likelihood of shrinking, fading, bleeding, and damage.

A cold wash also minimizes wrinkling in synthetic and sturdier fabrics.

There are 2 exceptions:

  1. If you live in an area where the tap water can be as cold as 40 degrees Fahrenheit (Maine and Alaska, for example), you’ll need a newer machine that automatically adds some hot water to the cold cycle. Otherwise, the detergent won’t dissolve properly. Alternatively, you’ll have to wash in hot water.
  2. A cold wash cleans fine, but it doesn’t sanitize. If someone is sick and contagious or if you use reusable diapers, you’ll need to sanitize which means washing in (very) hot water.

Bottom line: unless you live in Alaska or need to sanitize, always wash in cold water. It saves energy and gets clothes cleaner.