We find the yeast deoxygenation method is a very viable way to mitigate DO in brewing water. Thanks to our good friend Bilsch he came up with this method and here is an excerpt from him:
“Someone said to me, in the context of pitching in oxygenated wort, yeast are the best oxygen scavengers we know. Shortly thereafter, while reading up on calibration of DO meters, I came upon the mention of zero water and the ways to make same. This got me thinking maybe we can harness the wee beasties for more than just turning wort into beer. Possibly they can help us before the mash by cleaning up dissolved O2 in our brewing water and save the time and energy needed for boiling and cooling the strike water. For lack of a better term, let’s call this process yeast oxygen scavenging. To that end, I did several small tests using cheap and available baking yeast for this purpose. It also seemed reasonable to assume that the yeast might need some fuel, beyond their reserved glycogen, to do their job more effectively. Initial tests employed dextrose and subsequent ones DME.
YOS test 1:
450ml RO water @27c in 500 ml Erlenmeyer flask with stopper
0.2g bread yeast, dry
Initial DO reading- about 6.5 mg/l
1 hour – 0.33mg/l
2 hours – 0.27mg/l
3 hours – 0.31mg/l
5 hours – 0.36 mg/l
17 hours – 0.47 mg/l ”
We find for us, the dextrose/bread yeast is the best bang for your buck and it is very easy to scale off of this test by using the dextrose and a dry bread yeast at a rate of twice your batch volume (not beer batch, water needed for deoxygenation) in grams (i.e. 5 * 2 = 10 grams each of dry bread yeast and dextrose). Or 2g/gal for easy dosing.
New and updated on this post
This is more thoroughly discussed in the original thread if you want to read into it.
Good luck and let us know!