Hmm..I really don't know. I did use a bottle a while back from the laxtive section at CVS and it didn't state vegetable glycerin. I didn't notice any significant differences when I used it in my mixture.
Also, but glycerine and cold weather - Glycerine is a humectant, so it absorbs moisture from the air. When the weather turns cold, there is less moisture in the air, so the glyerine will then begin attempted to get it from your hair. In order to keep this from happening, make sure you mix the glycerine with an equal amt of water in your spritz. I use Rose Water and I have no issues with it drying my hair out. I live in the desert, so technically, it should be drying my hair out year round, but using this tip I've had nothing but success with it.