I don't really understand how they can add more flavour without throwing off the VG/PG ratio.
Thanks for any input on this.
You just use less plain PG in the mix. Most flavorings are primarily PG-based, and so are just counted towards the PG total in a final mix. So if you up the flavoring percentage, you just drop the added PG by the same amount and you end up at (basically) the same ratio. A simple recipe might look something like this, for 100ml of 50/50 at 6mg/ml:
50ml VG
34ml PG
10ml "flavoring"
6ml "nicotine juice"
...but remember, the "flavoring" and "nicotine juice" are not pure ingredients. Flavor is usually in a PG base, and nicotine can come in either PG, VG, or a mix of both. Many people use PG-based nicotine because it makes the math easier (just call everything that isn't VG "PG"), and a concentration of 10%, or 100mg/ml, is common among DIY and professional mixers alike. So when broken into its constituent parts, that looks more like this:
"VG":
- 50ml pure VG
"PG":
- 34ml pure PG
"Flavoring" - 10ml of a solution of flavor molecules in a PG base consisting of approximately:
- 1ml flavor molecules
- 9ml PG
"Nicotine juice" - 6ml of a solution of 10% freebase nicotine in a PG base consisting of:
- .6ml freebase nicotine
- 5.4ml PG
...and lumping all the PG back into one place it would be:
50.0ml VG
48.4ml PG
1.0ml flavoring molecules
0.6ml freebase nicotine
If you used twice the flavoring (+10ml "flavoring"; really +1ml flavor molecules, +9ml PG) and took out that much plain PG (-10ml PG) you end up with:
50.0ml VG
47.4ml PG
2.0ml flavoring molecules
0.6ml freebase nicotine
So you can see the
actual amount of PG has changed very little, since most of what was taken out as "PG" was put right back in as "flavoring," and the VG and nic amounts have not changed at all. Both of these liquids would be called "50/50" on the label, even though neither one of them actually contains exactly 50% PG.