So for starters I recently made a batch of juice (if you can call it that) that is 8% menthol (also made myself with crystals dissolved in pg) and 92% vg and there is a white layer on top of the juice which I’m assuming is the menthol because i do not get any menthol feeling. So the question is why didn’t it mix correctly and is there any way to once again dissolve the crystals?
Because menthol doesn't dissolve well in VG. Most people use a 10% dilution in PG and then add that to their mix at somewhere around 0.5-2% (or more if they have a tolerance).
You're using significantly more than than you need and it likely won't stay homogeneous at that concentration.
So I should mix 90vg with 10pg and then add 1-2% menthol?
You should mix up 10% menthol crystals to 90% PG and then add that as a flavor in your mixing calculator (i.e. https://alltheflavors.com/flavors/the-flavor-apprentice-menthol-liquid-pg) somewhere around 1-2% or if you like really strong menthol, bump it up. You can always add more.
If you're at the 8-10% Menthol mark (assuming your Menthol concentrate is a 1% solution), you need around 30% pg to dissolve it. Add Menthol to pg, run under warm water and make sure there's no cloudiness to it, then add the vg and you should have a clear juice that doesn't cloud up unless very cold
What was your dilution for the crystals. And why use 8%? That's rather high, and if your math was correct for the dilution, that's probably why the menthol is seperating.
I have used too much before. Sit in a cup of warm-up water this should dissolve the crystals a bit and shake the fuck out of it. You can try to squeeze the crystals out too. Just use much less next time as has been suggested. Koolada is a good one to mix small ammounts with menthol. WS-23 is great to, only use 1ml it's strong as fuck.