gsub:
Also keep in mind that "boiling" water has pockets of steam at 100C, hence the bubbles, but the total average temperature of the water will be slightly lower. If it were all 100C it'd be steam, not liquid.
Not correct. At boiling the water reaches 100DegC but to turn into steam, liquid molecules pay latent heat of vaporization. Simply reaching 100DegC won't turn liquid water to gaseous water.
The bubbles are absorbed air being released as water at higher temperature can dissolve less air as it does at lower temperature. They are NOT steam. Steam only comes out of the surface. Welcome to the world where everything makes sense only if you know physics! Good intent to help but please read next time before you try to explain something you aren't sure about.