Adding potassium metabisulphite (i.e. sulfites) to prevent oxidation?

I know this is an old post, but I would like to add a point to the discussion. Oxidation in beer is primarily a concern for heavily hopped styles. From my understanding and experience, oxidation leads to diminished returns on hop aroma and staling of the hop compounds. Since dry hopping often involves racking to secondary, I think metabisulfite added at this stage (and at bottling) would make a significantly hoppier and fresher tasting DIPA that could hold up to the time it takes to age in bottles. Any thoughts?

The only thing I use potassium metabisulfite for in brewing is the dechlorination of my tap water.

I use k-meta in winemaking for several purposes:

1. To stop the naturally occurring wild yeast and bacteria on the grapes immediately after crushing. After sulfiting the must to ~40ppm, I let it rest for about a day before pitching my cultured yeast. This first sulfite addition doesn't map well to brewing because the wort is boiled, thus driving off any baddies.

2. To prevent oxidation.

   • Wine is bulk aged for years, then bottle aged for years more. Oxidation can really take hold in that time frame. Most beers are consumed within a few months.
   • Wine is racked from carboy to carboy up to a half-dozen times before it's bottled. Each racking potentially exposes the wine to oxygen. With beer, you rack zero to two times (none if your fermentor has a spigot, once if you need to rack to a bottling vessel, twice if you secondary). The potential oxygen exposure is much less in brewing than in winemaking.

Finally, messing with sulfites in wine is a pain. If you don't monitor your free and bound SO2 levels, you can over-sulfite your wine, ending up with a strong rotten-egg taste, or under-sulfite it, resulting in oxidized wine. It's a necessary hassle in winemaking, one that I'm glad I don't have to deal with in brewing.

I spent 2 years experimenting with adding campden in an attempt to discern it's effects on oxidation. I finally stopped doing it after noticing no difference. That told me that either the campden did nothing or that I didn't have any issues for it to correct.

I make wine and beer and I use sulfite solution for sanitizing my equipment and bottles for both beverages.

I haven't added sulfite to my beer specifically to prevent oxidation though I would imagine that the residual that's left from my sanitizing does help prevent that from happening.

I know wine yeasts have built up a tolerance to sulfites which is why you can add sulfites to fermenting wines and be okay, it just kills off any wild yeast or other microbes that may be present. I'm not sure if beer yeasts have this tolerance.

I can't imagine why you would do this, although I will check out the show and amend my answer if I receive enlightenment.

In three years and sixty plus batches, bottled and kegged I've never had oxidized stale beer.

You just have to be careful in handling the beer to prevent oxidation, in racking, transfer to keg or bottling bucket.

Furthermore, you can't naturally carbonate if you prevent yeast growth. Wouldn't matter in kegging at least.

Oxidation is NOT a huge concern. It's one of those things you have to be careful of but I honestly can't imagine anyone finds this an overwhelming enough concern to add a (albeit safe) chemical to their beer.