Who let's their VG sit in hot water before using it? I've been doing it lately so it's easier to mix, and I find there's very bland flavor in my juice until it cools off. Anyone have an explanation?
You are just warming up the VG? I don't know that there's really any reason to do that. It mixes just fine right out of the bottle. Are you mixing by volume?
I mix by weight. It's easier to shake with the thin VG.
I mix my weight as well. I have never had a problem with shaking the mix. Even when I used to mix with no added PG
Not only that, but thinner VG bonds with PG and flavorings easier so that the entire juice is more uniform. This can* reduce your steep time and once you let it cool then give it another shake, you may find that the flavors are a little more blended and taste better than if you didn't warm your VG.
This process is called homogenization and it's pretty common in chemistry to warm a more viscous liquid to mix it with less viscous liquids. ALWAYS mix by weight (this is more for other people reading this comment as you said you already do mix by weight) when warming your VG. Warmed VG, like nearly everything else in the entire world, will expand when heated so 1ml when warmed may only be 0.75ml when it cools.
*steeping is still necessary, but your steep time may be shortened by a day or two via a homogenized batch. Sometimes you may not even notice any difference at all. I "speed steep" using homogenization by placing my juice in a warm water (130F) bath for 1 hour, removing it and shaking it every 15 minutes
I warm my VG before use for the same reason, just makes mixing easier. I don't know the scientific explanation but my guess would be that it's not flashing from a cool state to vapor but from an already warm/hot state to vapor. I usually let my mixes sit a day before I go to town on them.
I measure about the amount of VG Im going to use - about 200 ml and heat in the microwave a couple of seconds before mixing. I use funnels with thin necks to pour into my bottles while on the scale and it just makes it pour faster. I don't vape just mixed juice though, so I've never noticed a difference.
Grab some plastic squeezy bottles. They are like 3 for $2 at bed bath and beyond.
I use a soft plastic 16-oz barbecue sauce bottle from Walmart. It has a Yorker-type cap with a spout and it works great. The large mouth on the bottle makes it easy to refill from a gallon jug of VG, no funnel needed.
Only disadvantage: each drop from that big spout weighs ~0.1g.
Get a cheap magnetic stirrer and no shaking is involved, got mine of AliExpress for iirc 25-30$.
I wanted to do this. But, how do you get the little metal piece out of the bottle once you're done mixing it?
It depends on the amount of liquid but tweezers or as the other guy said magnet on a stick, but if you are a concerned with contamination and such you can just run a magnet on the outside of the mixing container in order to retrieve the stir magnet kinda like how you clean a aquarium.
Warm VG is fine. Hot VG will heat up your flavorings or nic and cause reactions to go fast. Sometimes you don't want that. I've found it can screw up flavors. I will warm my VG jugs with hot water in the sink before I get to pouring, but I usually only do this when it's cold in the house. It makes pouring and blending easier. Warm is the key, not hot.
My opinion from my experience, I'm not a chemist.
If the room where you store your VG base is cold, or If when you shake your VG mix you see forms in the bottle that look like you broke an ice-cube in two, warm the VG/mix a bit you'll save yourself headaches.
I made a batch of high VG mix without warming/thinning the VG after reading that it mixed "fine" without warming it, and that batch tasted like crap because some flavor didn't mix as well as some others after shaking my mix compared to when I warm the VG to thin it.