Why are some stains easier to get out with hot water than cold water, and vice versa? Is there an easy way to remember (color, consistency, etc.)?

Question

Why are some stains easier to get out with hot water than cold water, and vice versa? Is there an easy way to remember (color, consistency, etc.)?

In: Chemistry

Answer 1

This is only a partial explanation, but: Firstly, unfortunately there isn’t an easy rule to remember. The closest I know of is that stains that have proteins in them (blood, milk, infant formula, egg, semen) should be washed in cold water, because the heat of hot water can cook the proteins and cause them to bond more with the fabric of whatever it’s staining.

Unfortunately it’s not even “bodily fluids” you can classify here, because urine, sweat, and vomit are all better handled with hot water.