I brew LODO where it benefits the beer. Some beers don't benefit. Some beers I would take care on the cold side to prolong shelf life.
I dunno. Dr Charlie Bamforth (Beersmith "Flavor Stability" podcast #74) said “In regards to sweating the small stuff over trying to minimize air uptake in wort production and so forth, I wouldn’t waste my time and effort on that.”
He also said, that using de-aerated water or nitrogen-purging the grist are "overkill". …but if he chose one it would be purging the grist because there’s more air in it than in the brewhaus liquor.
Instead, he recommended focusing on minimizing air in packaging and keeping packaged beer cold. He said those are the two biggest things you can do for shelf life while recommending against dosing with sulfur based compounds.
From what I understand, oxidation in the mash is caused by O2 reacting with divalent cations (manganese, magnesium, zinc — cations with valence of 2+) to create superoxide, free radicals.
Problem is once those oxidation reactions occur, the compounds created continue all the way thru to the packaged beer and cause staling.
Instead of focusing on reducing/elimination of O2, I think time is better spent focusing on the oxidation reaction that’s occurring. Reduction or removal of these ions reduce the incidence of these reactions regardless of the level of oxygen present.
I believe by using heavy metal chelators that can trap the divalent cations, you can reduce and possibly eliminate the oxidation reaction. So, I add 1/2 tsp of hydrated Brewtan B directly to the strike liquor prior to mash in then underlet the grist. According to Joe Formanek, “This has worked well in systems where there is an inherent high level of DO due to equipment used.”
After the mash is complete, transfer quietly to the BK, keep the wort hot until boiling, cool quickly and pitch plenty of healthy yeast, closed transfer to a purged keg as soon as fermentation is complete (or just prior and spund), and keep the beer cold while conditioning and serving.
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