just what is the vapour ?

[aardy]

if you use vg with zero nic.
is it just steam? is that what hapens when you heat vg , just steam ?

 

[Odsbodkins]

Most of what you see is vaporized glycerin (vegetable glycerin). I can't prove it, but I don't think there's enough heat to generate a cloud of visible steam, although there is some water in the vg.

 

[dormouse]

It's like the fog machine at a concert. Vaporized glycerine and water.

 

[markfm]

Both PG and VG are humectants. When you vape, the vaporized PG or VG basically sucks water out of the air in your mouth/lungs, the exhaled vapor is mainly all the water that the PG/VG has attracted.

That's why you have to drink a lot of water -- vaping dries you out.