Post by HowardPost by Bill O'MeallyThe sour wort is currently sitting on the fruit, after which I will
rack into a corney keg purged with CO2, and in which I will dry hop
for 5 days. Thinking of adding a pinch (maybe about 10 ppm)
metabisulfite to scavange any small amounts of oxygen left in the mix.
Winemakers do it all the time to prevent oxidization. Why not
brewers?
<http://brulosophy.com/2019/02/11/post-fermentation-oxidation-the-impact-
adding-sodium-metabisulfite-at-packaging-has-on-beer-exbeeriment-results/>
http://brulosophy.com/2019/09/23/cold-side-oxidation-impact-of-dosing-beer-
with-sodium-metabisulfite-smb-at-packaging-exbeeriment-results/
<http://brulosophy.com/2020/03/23/cold-side-oxidation-impact-of-dosing-
beer-with-potassium-metabisulfite-pmb-at-packaging-exbeeriment-results/>
The blind taste tests for sodium metabisulfate found a significant number
of people could tell the difference between dosed and undosed beer, but
opinions about which was better were split.
The potassium metabisulfite taste test did not find a significant number of
testers who could tell the difference.
Obviously it's only limited data points with a lot of other possible ways
of testing, but I think it's still interesting.
Thanks for sharing these exbeeriments -- I found them fascinating. The
one where he uses SMB for a NEIPA in <cringe> unpurged kegs was
especially apt for me. The beer without the sulfite was obviously a bit
oxidized at only 5 days after kegging, when compared with the sulfited
keg. Interstingly, the former was deemed to have a bit more hop
character by the exbeerimenter initially, only to be surpassed with
time by the beer with the sulfite.
I never realized, or at least forgot, that metabisulfites will also
scavange chloramines in the brew water.
Regarding kegging, keeping in mind that even with multiple CO2 purges,
there will still be a few ppm of O2 in the mix (according to that
partial pressure of gasses stuff I vaguely remember from college). One
way around that is to fill the keg with sanitizer solution, then purge
that out completely with CO2. I am feeling a bit more emboldened to use
the PMB (never used the sodium, which was deemed more noticeable though
not necessarily in a negative sense) that I use for winemaking with my
brewing. Especially with my more oxygen sensitive dry hopped beers.
Again, thanks for sharing!
--
Bill O'Meally