White stains & muddy deposits in stainless steel pots

Question

I use stainless steel pots on an induction cooker for boiling water for preparing food for an infant. I use bottled and supposedly clear and soft water.

When I pour the water into the pot it is crystal clear. I noticed that after boiling it's not that clear anymore. It's somewhat muddy and has visible whitish deposits.

I also noticed that there are white round spots on the bottom of the pot. When the water is boiling, apparently those spots are where the bubbles appear. I bought a brand new and not-so-cheap pot today and after the first use the same spots appeared.

I am not absolutely sure, but I think the two issues are related.

What is happening? How to prevent it? All I'm interested in is boiling water that is as clear after boiling as it was before.

Answer 1

Boiling water leads to evaporation, which leads to concentration of anything dissolved in the water (and there will, unless your water is distilled, always be something dissolved in it); that concentration can lead the water to be supersaturated and for trace minerals to precipitate out of solution. If you are getting water from your municipal mains, chances are it's perfectly safe either way.

The appearance of 'muddiness,' however, seems very weird to me. Water can't become muddy on its own; by 'muddy' do you mean 'cloudy'?

Answer 2

Your bottled and supposedly soft water isn't soft. Perhaps the manufacturer even adds Calcium to it? Some brands are high in Calcium.

Those white round spots where bubbles appear are likely mineral deposits. They form nucleation sites for boiling. A dishwasher may not remove them, but a soak in vinegar, followed by a scrub with steel wool will. Calcium in water is not a problem, but it's odd that you get cloudyness after a short(?) boil. What kind of jars does this water come in, plastic?