e place on this one. Best I can find is to fill whatever bottle you're using 3/4 full with crushed menthol crystals, then add PG. It does help to warm the PG. Then shake it like hell to get the crystals
From what I've learned this is true. I did the same thing with ethyl maltol (sweetening) crystals. I heated up a small pot of water on the stove and put the mixture of PG and the crystals inside of a glass bottle and heated up slowly. After it was warm (about 5-10 mins) and swirling occasionally (I don't suggest leaving the container closed while heating!) the crystals dissolved and I used that as a sweetener.
However, with the menthol crystals, I used to just drop a few small pieces into the (30ml) juice that I was making and closed / shook the bottle until dissolved. That seemed to do just fine but now I just use the pre-dissolved menthol liquid which is a lot easier.
TLDR version:
Use sparingly, add as last ingredient, shake the bottle, add more if needed.
Also, I know that I'm very new to the forum so I might not be trusted, but I've been making my own juice for about 3 years now. Take that for what it's worth.