So when different clothes prescribe washing at different temperatures, it's because the ‘activation’ temperature of detergent changes depending on whether you use it with jeans or underwear?
As far as I know the clothes don’t prescribe a temperature to be washed at, but rather a maximum temperature threshold upto which the material can withstand without risking damage to itself.
So a 40°C cloth can be washed at any lower temp but might deform or loose color or even breakdown if washed warmer than that.
Instructions haven't kept up w/ washing machines and detergents.
> "Front-loaders and high-efficiency top-loaders run normal cycles 10 percent cooler than agitator washers, and the 'warm' wash temperature in the U.S. has declined by 15 degrees over the past 15 years," says Tracey Long, communications manager for P&G's fabric care products in North America. “Traditional detergent enzymes can be sluggish in cold water so we worked to create a mix of surfactants and enzymes that deliver cleaning performance in cold water across all product lines," says Long.
> Consumer Reports’ past tests found detergents have gotten much better at putting enzymes to work in removing dirt and stains at lower water temperatures, and are less effective at higher temperatures.
If you want to sanitize anything, just use some bleach. It's harsh on fabric, but so is hot water, and the bleach will do a much better job. (FYI, I don't have any whites at all.)
My understanding that was for the special fabrics and/or the dyes used. For example raw indigo bleeds a whole lot more with higher heat. I know there are some fabrics and blends that are fragile compared to something like a cotton tshirt and recommend colder water.
