I have found sour - Malic acid to be useful in fruits that need lifting helps them " pop " I’ve been messing around a bit w/ some deeper diy additives but have been busy so haven’t had the time to test them, but my theory goes like this…Malic acid use it as the higher % in the recipe then follow it w/ a lower % of Ascorbic acid to reduce the PH level of the juice as Ascorbic acid by nature reduces PH.
Sour PH levels - anywhere from 2-4 ( think willy wonka sour candy )
** A little bit of nerd science here ** PH Levels are Acidic below 7 and basic or Alkaline above 7
7.35-7.45 is the acidity of our blood, and tap water is supposed to be at 7.0
Deionized water - 5.0 but when exposed to air it can quickly return to 7.0 d/t introduction of carbon dioxide present in the atmosphere. http://www.mrlhydraulics.com/uploads/Propylene_glycol.pdf
Battery acid is to be considered around a PH of 1.
Ascorbic acid is sour. One definition of acid is a proton donor. Adding protons to a solution increases the hydrogen ion concentration (lowers pH). Taste of sourness in the taste buds is due to detection of lower pH than neutral. Our brains have evolved to interpret low pH as sour for some reason. So, from that explanation we can say all acids have a sour taste, but there are many other factors that affect taste, a molecule may contain other functional groups that can stimulate other taste buds like sweet or bitter. An example is aspartame, it contains an acidic carboxylic acid functional group but it tastes sweet because it can stimulate sweetness receptors by the formation of hydrogen bonds and hydrophobic interactions with the taste “triangle”. Aspartame is used commercially as an artifical sweetener in drinks like Diet Pepsi.
The artifical sweeter potentiates the effect of the acid like wayne is saying. I agree
VG PH seemed to vary highly on searches from 6-9
PG PH varied greatly on seaches as well from 5-9
As of now I am using sour anywhere from 0.5-2% w/ no real sourness just lifting the citrus acid notes in the fruits.
I will eventually test the Ascorbic acid batches that had Ascorbic Acid around 0.25-0.5% and sour around 1-2% I did a few batches and made a couple % changes to them to see how they would react.
Interestingly it seems that each manufacturer has their own " blends" with whatever their buffering pg/vg in outside of the known chemical structure so testing your bases will provide you w/ a ph level… I have some Ph level strips but my guess would be since we open and close our bottles so often this would create more of a neutrilized PH eventually this must be the reason for the varying of levels found online.
Then I looked around some more and found that once Pg is heated it can drop in PH again varying between 4-6 Page 81 http://fire.nist.gov/bfrlpubs/build85/PDF/b85009.pdf this was a w/ heating of copper/ other metals.
For Pg Sensitive ppl like myself these additives are in VG !