What amount of nic?
"Tongue burn" is something I am very familiar with from smoking, and I noticed to my surprise that in
vaping it seems to be even more related to nicotine strength than when smoking.
Now, nicotine isn't the whole story - I have vaped higher than my normal nic level in pre-made juices and been astonished at the lack of "tongue burn", and managed to get the effect in some comparatively low-nic mixes of my own. But I can say with certainty that I've never experienced it with zero-nic liquids.
I don't know what the secret is to mask or avoid this "bite" - yet...
My grandmother detested cigarettes with "tongue bite", and was very very unhappy when at some point in her early eighties her regular brand not only started tasting foul to her, but also started giving her "tongue bite".
She went to the doctor and complained. The doctor was luckily a sensible man, and understood that lecturing a healthy octogenarian on the dangers of smoking wasn't a very sensible thing to do. So after looking carefully at her mouth and throat and finding nothing amiss (and asking her to follow up with her dentist just in case), his suggestion was:
- Try another brand for a few weeks? Maybe even menthol?
And this my grandmother did. After trying a few different menthol brands, she weirdly enough settled on Newport
(which *I* thought had a horrendous "tongue bite" - go figure; I think she probably settled on it because if every cig gave "tongue bite" and tasted bad, why not choose the most menthol-y and the strongest and harshest? A cig meant to be mild that tastes harsh is horrible, a cig meant to be harsher can at least be appreciated on its own merits), which she smoked for a few weeks.
After about a total of three weeks smoking menthol, she tried her own brand again. Success! No tongue bite or foul taste anymore! Hurrah for the best GP ever!
So maybe it might help you, Xmit, to let your tastebuds rest for a few weeks, and make yourself a very simple menthol-juice at as low a nic concentration you can get away with? Or try alternating unflavoured, zero-nic, with your normal vapes?
(I have a very very simple juice that I find myself vaping more and more of - as an "in between": It is 5% mint flavouring at 10mg/ml, probably about 70/30 PG/VG. About every 3rd fill of the same carto I put one drop of my weakish menthol-spirits in the carto-condom when I re-fill. This was made with a mint flavouring from
Twojliquid.pl.
(Who unfortunately doesn't say exactly what is in it except for "purest PG" and "original Italian components" - they do sell FA tobaccos, but insist that the non-tobacco flavourings are not re-labeled FA, I guess they might be creating these flavourings from super-concentrates - I don't know how many Italian manufacturers of flavouring/scent raw-materials there are that we as consumers have no knowledge about at all.)
Eh, point being I find myself using this mint juice, with the occasional addition of a dash of menthol (and the occasional addition of unflavoured juice) quite a lot. My mouth likes it

)