"Minimum Effective SO2" ??

Some wineries that are using ingredient labeling will state "minimum effective SO2". Some of them are in the
"natural" wine camp (Donkey&Goat), some are not (Ridge).
What kind of numbers (total SO2 at bottling) are we talking here:
1. White wines
2. Red wines
3. Wines w/ RS

Tom

depends on pH, I'd say

[David M. Bueker]

thXA55CJNK.jpg

I haven't checked to see how precisely this answers your questions, Tom, but this is by far the best online resource I have ever found for detail on SO2 in wine, and I think it will help:

http://www.brsquared.org/wine/Articles/SO2/SO2.htm

Warning: from what I remember, there are no simple answers

All the above plus alcohol and residual sugar content. The higher the alcohol, the less SO2 is needed. The higher the pH the more SO2 is needed. Sweet wines require more SO2, but there is not a scale, only a level. The first rule I recall is for 5 mg/l for dry reds, 8 mg/l for dry whites and 1.5 mg/l for sweet whites at pH 2.8 with the amount increasing as the pH get higher. Here's another link: https://www.extension.purdue.edu/extmedia/fs/fs-52-w.pdf
FWIW - generally, most reds are in the pH range of 3.4 to 3.8 and whites 3.1 to 3.5.