Originally Posted by waves

so, fizzing tells you the reaction is not complete - that's why you need to wait till it stops before you drink up or do anything else to the preparation.

So then.... how hot does "hot" need to be?

At one point I'd found a chart that told me optimum solubility temps for bunches of salts in different solvents. Alas, I cannot find it again! What I do personally is heat water as though i were making instant coffee... i bring it to steam point but not to a full boil (as i would for tea). Then I add the stuff and then i let it cool down. that's probably hotter than needed but i am sure, that way, that as it cools it will certainly pass "through" critical solution temperature.

hope that's helpful and not too chem-geeky.

~ waves ~ a once-wannabe chem major