DIY High % Menthol Concentrate

So about a month ago a user directed me to a 66% menthol concentrate sold by ecigexpress and it was exactly what I was looking for in my DIY menthol liquids. When I began to run low, I decided to pick a massive jar of menthol crystals and make my own, rather than order another pre-made bottle. I researched how to DIY menthol concentrates and whipped up a batch with 34% PG and 66% crushed menthol crystals. I gave it a hot water bath for 10 minutes or so afterwards, and the crystals dissolved perfectly.

I just went to mix up a batch of my menthol liquid and found that the menthol crystals in the concentrate recrystallized. I know this is a problem when diluting menthol crystals in VG, so I used 100% PG for dilution. I'm a bit stumped here, since I've never read anything which indicates that menthol crystals will recrystallize in PG. Perhaps it's because I'm using such a high concentration of menthol crystals? I imagine that I can solve this by giving the concentrate a 10 minute warm water bath right before I use it, but clearly there is another way to do this which doesn't require that step, since I can order a bottle with the same menthol concentration online and it won't have this problem.

Any ideas?

EDIT: Never mind, I figured it out. According to the site they use a mix of 66% Menthol Crystals in 34% PGA, not PG. Should have checked that first before making this post. My bad.