Beer Flavour Stability in Home Brewing

[Tuur Mertens]

For those interested in keeping their beer fresh and enhancing beer flavour stability (shelf-life) during brewing, I wrote an introductory article about it here:
http://www.lowoxygenbrewing.com/brewing ... e-brewing/

Feel free to ask any questions or give comments of you have any.

Kind regards,
Tuur

[Beer-lord]

Welcome to the Borg Tuur!
I've read so much about this and listened to even more podcasts about it. I've tried, as much as possible, to keep oxygen out but have to say that I personally think that for the average brewer, some of this is overkill. Certainly oxygen will hurt and affect your beer and taking care not to shake or aerate after fermentation has started is a priority but I've brewed 100's of beers and try to drink them as fresh as possible and can't say I have had a beer ruined by oxygen.
Now, if I were to take all the precautions suggested by many and compared 1 beer to another, I've no doubt that I'd see a difference, especially the longer they age but I think the simpler thing to try when packaging would be to add some SMB (with care of course).

Thanks for sharing. I very much enjoy reading and learning about new things and how to make hombrewing better.

[mashani]

The only place I think going totally overkill on the upstream side (vs. just doing all of the common sense basic things) might make significant difference "in real life" for many home brewers is for highly dry hopped hazy IPAs that do really go a bit flat after 3-4 weeks or so. But that is tricky because the very process of hopping them the way they are is part of what introduces the upstream oxidation. You would almost have to dry hop them in a "bubble", or introduce something that removed all oxygen again post dry hopping, IE you could hit it with campden, that will remove all of the oxygen. But if the "biotransformation by yeast" is actually important, then you can't do it then because it would murder the yeast, but you could still do it right after the hops are pulled. You would need to introduce a bottling yeast strain though after if you wanted to bottle prime with sugar (kegging, not a problem though).

Otherwise, I've never had any issues with oxidation ruining any beer I make before drinking it. Hoppy beers I am drinking in 1-2 months or so anyways, anything that I'm aging more then that long is a non-hoppy Belgian or such style.

There are actually some aged non-hoppy beer styles that would potentially be make worse if we could actually remove every bit of oxygen post fermentation and/or just increase the required aging time if you removed a good chunk of it. Because those styles actually develop some of their flavor character from the slight amount of oxidation during aging. Think aged styles that develop sherry like characteristics desired in the style. Flemish browns or reds, some other strong ales.

In aged "live bug" (not quick kettle) sour brewing we actually sometimes encourage slight amounts of oxygen during the long aging by using things like wooden dowels to plug up the carboy instead of an airlock. For those same reasons, it helps develop the proper character in those beers. They would have been traditionally fermented and aged in wooden casks, slight oxidation has always been part of their "life cycle" as such in traditional brewing process.

Personally I find whatever the minimal process there is required to create the beer I want, and roll with it. Adding more "work" to achieve a minimal gain like making my normal IPA stay more stable for 4 or 6 months isn't worth it when I am just going to drink that IPA in a month or two anyways. I just minimize post fermentation oxidation by following common sense processes and don't stress about it.

[Tuur Mertens]

Welcome to the Borg Tuur!
I've read so much about this and listened to even more podcasts about it. I've tried, as much as possible, to keep oxygen out but have to say that I personally think that for the average brewer, some of this is overkill. Certainly oxygen will hurt and affect your beer and taking care not to shake or aerate after fermentation has started is a priority but I've brewed 100's of beers and try to drink them as fresh as possible and can't say I have had a beer ruined by oxygen.
Now, if I were to take all the precautions suggested by many and compared 1 beer to another, I've no doubt that I'd see a difference, especially the longer they age but I think the simpler thing to try when packaging would be to add some SMB (with care of course).

Glad you liked it. I tried to arrange the article in such a way that the easy (but extremely effective) stuff comes first. If you keep your beer cold, the shelf-life can be prolonged significantly. If, on top of that, you drink your beers fast enough, you will generally never have a staling problem. It's as simple as that.

That said, and this is an argument a lot of LoDo guys will use, (hot side) oxidation during brewing will "destroy" a lot of the the fresh/crisp flavours that you might want to keep intact (especially when brewing German lagers). For sure it is possible to brew a good beer even without paying much attention to upstream oxygen; but in order to make a good beer even better (which you could rightfully consider overkill, as an average home brewer), the next logical step would be to keep oxygen at bay.

[mashani]

That said, and this is an argument a lot of LoDo guys will use, (hot side) oxidation during brewing will "destroy" a lot of the the fresh/crisp flavours that you might want to keep intact (especially when brewing German lagers).

Just to be devils advocate:

Except one of the traditional old ways of cooling German beer specifically introduces HSA. Hot wort was literally pumped through the air and run over the outside of cooling coils or metal plates, totally open the air - not through them like a counter flow chiller or immersion chiller. This kind of cooling was still used in some places until very recently. Maybe even still now IE, I think Anchor actually still has and does use something like this, because it literally was a traditional German brewing practice (I think Anchor mixed it with a contained chilling process, so it was a hybrid).

Before very modern times in the scale of things when it comes to brewing there was literally no consideration of HSA as a thing and people made beer. Hell in the 18th century it was pretty common to literally toss the wort through the air between containers to cool it, if not simply put it in an open vessel and allowed to chill overnight.

I have done pretty much *everything you can imagine* that would in theory introduce HSA over the years and have never had a beer affected by it whatsoever. I know many other home brewers who have also experimented with HSA to see if it did anything at all at our scale. The consensus among all the people I know who have tried it suggest that it doesn't happen at our scale, and is simply not something to worry about. It may very well be something to worry about in a commercial environment where pumping beer through hundreds of feet of pipe, but we aren't' doing that.

IMHO the "crisp" flavors in a lager come from using the proper yeast and the proper water profile to support the yeast - it has nothing to do with the hops and/or hop oxidation. Lager yeasts and also some ale yeasts like Kolsch strains produce sulfur, and although it dissipates below the level as perceived as "sulfury", it is this very characteristic of the yeast strains that I know of that produce that "crisp" flavor profile in the end product.

Maybe a highly flavor/aroma hopped BoPils would benefit for long term stability, but I would be skeptical that it matters for anything else besides highly hopped IPAs at our scale.

Slight oxidation in a bittering only hopped beer actually helps replace the AAUs fading by a reaction that takes the beta acids which are "forgotten" when it comes to value by many, and converts them into a bittering compound. It actually helps keep the beer "stable" as far as perceived bitterness in that regards when using low AA / high beta acid hops. Which pretty much all noble hops are. It is one of the reasons you should use them for bittering in such a beer instead of a modern high AA hop with less beta acids. There is a method / reason for them to be the tradition as such. Maybe if using a high AA / low beta hop, you would experience a significant loss of bitterness though. But I would argue that in a traditional German lager, you should never do that, and use the hops that are supposed to go in it.

Only when the oxidation starts to turn your beer into something that tastes like cardboard does it start to be a problem. I've had bittering only hopped ales and lagers using noble hops as much as 2 years old in the bottle that I theoretically introduced HSA in by process not ever achieve this sad state of affairs, and were perfectly good beers at that age, just as good as they were at 3 months.

[MadBrewer]

I will probably be the odd man out on this one. I joined the low oxygen brewing forum a few years ago and have been playing around with low oxygen brewing ever since. I have definitely improved my beers overall and learned a lot along the way. A few adjustments/additions to my process and it's been well worth the effort. Biggest improvements have been lighter color beers, clearer beers, beers that have a lingering fresh malt flavor (like you were to munch on a couple kernels of malt) and hop character that is clean, flavorful and long lasting. Overall drinkability of the beers has improved just making for a better finished product. Joining that forum and getting the idea to ferment, spund for carbonation and serve all out of the same keg was a game changer.

[mashani]

Oh don't get me wrong, I'm not trying to say the idea of it is "bad" or anything. I'm just being devils advocate and throwing out historical and style specific things (style is the more important one although most American brewers totally ignore those styles). And at least in my case, for the styles that it might matter in more, I'm drinking them long before it does in any significant way, so adding extra steps to my process personally would be silly.

If I was going to worry about post fermentation oxidation more personally, I would simply hit my product with potassium metabisulfite (campden) a day before bottling, just like I would do for mead or wine, and then add some T-58 or another bottling yeast strain at priming time (or keg and not worry about priming).

That will accomplish the same thing and is no extra work or process for me really (but I am not allergic to sulfites though).

Thinking about it, it is actually possible that one of the reasons my beers are seemingly vastly more stable then the low oxygen proponents would assume they should be (IE in that they never darken, they never change in any way as far as "malty flavor" is concerned, I may lose a bit of hop aroma over time, but I never lose much hop flavor... after ~3 weeks in the bottle, whatever it is at 3 weeks is pretty much what it remains) is that I do treat my water with potassium metabisulfite up front - always - both my brewing and my sparge water, and not just in chloramine reducing levels, but significant levels - because I use it as is part of my general water profile adjustment, not simply for chlorine/chloramine reduction. I guess I should experiment and brew the same beer side by side, one with my normal treated water and one where I just use RO or spring water and see if the RO/Spring water version changes a lot more. It is actually possible this will be the case if I did that.

[ScrewyBrewer]

Almost a year ago I did a few upgrades and started using Co2 to do closed transfers from sealed fermenters to oxygen purged kegs. Admittedly for me, using Co2 to purge oxygen from the mash or boil is something best left to the true LoDo brewers out there. But I've also replaced all the Co2 and beer lines with EVABarrier double-walled lines in a best effort to reduce oxygen levels as much as I can. Since making the upgrades there is an overall improvement in the freshness, flavor and aroma of the beers I've brewed.