I was making pasta and a vapor-like steam came from the inside of the pots. The first pot was a stock pot from Calphalon. I have used it for over 20 years. Vapor started before a boil but water was quite hot. I switched pots to an old stock pot and the same happened. I threw out the pasta. I was freaking out. I quit cooking the pasta. Yesterday I used the broiler. NO PROBLEMS AT ALL! I am fairly certain the vapor was inside the pot. As someone said, it was ghost like. If anyone has an idea I would love to get some advice. It is so weird and scary! Also a chemical odor is there.

  • 2
    Are you sure it wasn't just steam? That can happen with hot but not boiling water. I'm honestly having trouble visualizing what you've experienced, so I could be wrong. – Erica Feb 23 '19 at 23:47
  • Hi I am sure. It was very strange. Definitely vapor-ish. Picture a ghost type of image. Sort of cloud like but not as white or dense. – pamela Feb 24 '19 at 0:02
  • 6
    @pamela that is an apt description of steam. – AGirlHasNoName Feb 24 '19 at 1:50
  • Same kitchen as always, you haven't moved to a very different elevation or something? – Erica Feb 24 '19 at 12:36
  • Everything is the same. I am looking under the stove top but the vapor/steam is not coming from there. – pamela Feb 24 '19 at 16:39

Felt like I needed to join here to clear this one up.

What you've experienced here is not otherworldly, just physics and statistics. The following is a somewhat simplified explanation of what's likely going on.

What is temperature, and why is it important?

Temperature is an average of the amount of thermal energy in a substance. Some parts are warmer, and some parts are colder.

Water (at sea level1) turns to vapor once it reaches 100 C (212 F). That's true for any water molecule. Even if you measure your water to be at room temperature, there are still some molecules of water that, though sheer chance, happen to reach 100 C and turn into vapor.

The chance of that happening at room temperature is relatively low, but it does happen. Leave a bowl of water out long enough, and it'll all eventually evaporate.

As you heat the water to cook your pasta, you're adding energy. This raises the average level of energy in the water (i.e. increasing the temperature), and causes more water molecules to have enough energy to become vapor.

The other major factor

The dew point and humidity in your kitchen is also important.

Air at a given temperature can only hold so much water vapor. Once you fill the air with water vapor, it'll desperately try to get rid of it. Once a molecule of water vapor hits something it can glom onto (the side of your pot, the pot lid, a microscopic piece of dust, some starch that's flying through the air, etc...) it'll go back to being liquid water.

This is similar to something you've experienced plenty of times, fog.

Putting it all together

  • Your water is warm
  • Which means a fair portion of it is becoming water vapor
  • And it's basically turning into fog
  • Which can happen even before the water reaches a boil

Bonus, that "chemical" smell

Since you're cooking pasta, I assume you've added salt to your water.

Chances are pretty good that the salt that you're using is "iodized" (has the element iodine added, which is important for proper thyroid function). That's likely the source of your "chemical" smell.


What you've experienced is not strange, it's just how things work. Nothing to fear here.

1: Pressure affects the boiling temperature of water as well. Lower atmospheric pressure = lower boiling temperature. This is a factor in why recipes change for people at higher altitudes.

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