I have been vaping some juice with 6% EM and it was a little harsh. I just added 2 drops of lemon juice to 3ml and it smoothed it out a good bit.
Verrry interesting. I just recently experimented with a previous blend by tuning down the flavours used and adding one drop vinegar and one drop 10%EM (in 10ml - yes, I am über cautious), and my first impression was that the vinegar was a mistake. Weird irritating sweetness, my throat liked it even less than my palate.
I wouldn't initially have called it "harshness", since it was a very sweet taste/feel. But if I think about how my throat feels after vaping it, "harshness" is pretty spot on.
After thinking and vaping some more I decided that maybe it was the EM that I just don't like. So I compared to another, sloppier, blend, where I had also added about this much vinegar, but no EM. Yup, not the fault of the vinegar.
Why I should be so sensitive to the EM is weird. People say it doesn't really taste like anything in low concentration. Well maybe it doesn't, but it *feels* to me like burnt/caramellized sugar. Or at least it does when combined with M-type (tabanone) and my home-brew extraction.
But vinegar/lemonjuice/other acids are worth experimenting with - and it seems that it is hard to mess things up if one carefully adds 1 drp/5ml, let it steep at least a day, and then taste.