Steeping is the chemical development between the ingredients molecules to a concistent homogenious mix… They are everyone different from others, even in size and solubility. Steeping is the time the different compounds need to do this.
When you made a mix, it will have raw flavorparts eg in more or less “pockets” not homogenious mixed trough whole bottle.
Shaking does make this to start develope, but dont do any steeping process. You can force it as much -/ with what you want, heat - terrorise with a el saw, it dont steep anything.
Does 5 - 10 minutes of shaking giving a better mix than seconds, or faster steep? No difference, it will make your hands tired though… 
First i let my ingredients for sure have roomtemperature all trough before mixing… I shake quite gently some seconds (approx 2 - 10) without trying to crush mix totally, or bottle , and set it aside to steep dark and airtight in roomtemp.
This have been my routine in years, also as a commercial actor in ejuice, and never let me down tastewise. By forced steeping, i got differences in taste, most negatively.
Forcing by any heating is also No 1. for eg dry taste.
When making a new mix, after a few days the rawness of flavors starts calm down. Flavorwise it can close to disappear after a while, come and go, flavornotes change, etc… from day to day, week to week…
After some time, depending on flavors used, amounts and mix, it will stabilize and keep consistent in taste over time. Then it have close reached its potential.
Ive had mixes used 6-8 months before stabilized fully in taste, others approx 1 week.
Some mixes as more singleflavors/only a few used, can be ready in a few days, my experiences are approx. min. 5 - 7 days if very few flavors used in the mix… others min. 4 - 6 weeks, others far longer. A 3d steep aint steeped whatever!
Normally by fully steep, the flavors want change very much in its own taste after the fully steeptime , but the surrounding feeling of taste will change, altering “nuances” of flavornotes , as in a custard, with eg “rounder” more rich-/boldness in taste. The mixes will be a more a mouthfull.
Before this have happend… its not fully steeped, and still will change.
One of the best rules for a great mix is PATIENCE!
Make enough up front to vape on, so other mixes can be steeped enough.
By tasting time to time under the process, you will find out when the mix is ready. Making notes every time you tastecheck, your making your own “mixbible” for future reference use of knowledge.
Its not possible to say exact how long time every mix will take up front, as ellswise in diy mixing, its to much variables for that. Only generally could be stated, if not you tested your mix fully out, and know, your “just taked a chance”…
If the mix make some changes in taste, anything…its not ready steeped.
The big differences in moleculesizes, and types shows it will take the time it needs. This is not water and juice… its flavorchemistry.
Shake & Vape (SnV) is a unsteeped/undeveloped mix… and would anyway change over shorter time… hopefully to better, but falls easier to “ground”, by experience. If making smaller batches for shorter time use, well ok, but dont believe this would keep up in taste as in start over time…
Dont need steeping by adding only nicotine after?
Why does high VG mixes use longer time to steep than PG, for example?
Because the differences of molecule sizes.
VG - Molecular Weight: 92,09382 g/mol
PG - Molecular Weight: 76,09 g/mol
Nicotine: Molecular Weight: 162,23 g/mol
Vanillin - Molecular Weight: 152.149 g/mol.
The molecules of vanillin is bigger than VG… and thats a part of each flavor with vanillataste, Are also in some other flavors even if not typical vanillatasting.
This is reason eg Custards takes longer time to fully develope homogeneous,… its vanillamolecule is twice as big as the PG molecules…
Nicotine is even higher… so nicotine dont need any steeping?
“- so it all reality just to add your nicotine in at the end?”
By looking on the molecules of nicotine… they are bigger than VG… the higher content of VG are in mix/ or nicotine solution, the longer time for also nicotine to develop fully in a mix to a homogeneous state. It also need steeping… even if is “presteeped” in their solution (PG/VG), its not developed in the total mix for all parts to be homogeneous.
if you put a “clear” bottle of nicotinebase without cap, in light, …of a 100mg content it will degrade approx 1-2mg in first 2months. Excessive heat/air will degrade it in strength even more. By lower mg strength it will degrade less mg.
Degrading in a diy mix that stands airtight, out of light, would be so little it cant close to / or not be measured. Its no chemical reason/advantage for putting in nicotinebase after steeped. Just a disadvantage, because needs more steeping afterwards to be making a fully homogeneous mix.
By the way , steeping process, is that flavor molecules combine/develope to create new molecules homogenious, which hopefully mimic a better real taste…
Dont believe its right? Up to you, but this is known fact by flavorchemistry…and by some testing, you´ll find out.
