RY4 double has a lot of EM in it, it could have crystallized out of the solution. Warm it a bit in a warm water bath and it'll be fine.
what else is in there?
Odd.. I used to work at a vape shop and we used RY quite a bit and sometimes it sat for awhile.. never once saw it crystallize like that.
It's about a year old and been stored in a refrigerator. I noticed it a few months ago. I'm gonna heat it up a bit.
I am aware that a few flavors can separate or form crystals, especially ones with any “milk” components, like the malted milk, cheesecake, etc. The Flavor Apprentice advises to gently warm the flavoring and shake to dissolve and redistribute the flavoring chemicals back into solution.
You can use a microwave to heat the flavoring vial using very short bursts (1 to 4 seconds at a time) until it’s heated enough to dissolve the precipitation by shaking, but be very careful to check that it’s not too hot to touch before grabbing it out of the microwave.
It takes very little time to overheat a small amount of liquid in a microwave, and can result in a nasty burn if not careful.