I was recently witness to a discussion concerning the temperature of water for hand-washing of dishes. A man indicated that he often does this with cold water; his wife took him to task for this, saying that it’s well understood that warm water is needed, otherwise germs will cling to otherwise clean dishes.
My thought was that the maximum water temperature at which people wash dishes is probably around 120 degrees F - above that it’s too hot for comfort. And it’s a bit hard to believe that 120 is hot enough to kill many germs.
But it didn’t seem wise to intervene in this dispute without the facts. So I now put this question to the SDMB: when hand-washing dishes, how much more effective is warm water than cold?
If you put the dishes through a sanitizing solution, then cold is fine and the dishes will be just as clean. Me, I prefer hot water for two reasons. One: it’s psychological. The dishes just aren’t clean if they’re not washed in hot water. Two: hot water seems to make hardened scummy dishes easier to clean.
Dishes washed in very hot water also dry a lot more quickly, if you’re using a dish strainer. Which is handy for preventing spots, particularly on glassware.
Sorry, lemme try again. If the dishes are washed and rinsed and sanitized the temperature of the water makes no difference because the sanitizer (bleach or whatever) destroys most of the bacteria. If the dishes are simply washed and rinsed then hot water is better because while it may not kill germs as effectively than a sanitizer, it will kill more than cold water.
There was a thread recently about this topic but I can’t seem to find it.