Oxalate levels in beer

In an attempt to reduce the occurence of Calcium Oxalate kidney stones I've been instructed to reduce oxalates in my diet. My doctor gave me a sheet that said draft beer was bad but bottled beer was moderate. I found this Low Oxalate Diet paper and it says that 'dark or robust beer' is bad, 'draft beer' is moderate, and 'bottled beer' is good.

What assumptions are they making to say that draft beer and bottled beer are different regarding calcium oxalate?
Why are 'dark or robust' beers considered bad? Just because dark grains tend to be more acidic?
Anything I can do as a brewer to reduce Calcium Oxalate in my beer while not affecting quality?

I've seen those same statements and I think they are BS. Oxalate is produced (released) in the production of beer. Even if dark malts contain a higher proportion of it (which I doubt) it is easily removed by making sure that enough calcium to precipitate it is carried into the final beer. Good brewing practice demands that we do that as oxalate crystals suspended in the beer apparently promote gushing. That said, in over 20 years of doing this I have seen a calcium oxalate crystal in one of my beers exactly once.

Thanks AJ, I was hoping you'd respond. So, counter-intuitively it would seem, reducing the Calcium in my brewing water would actually be the wrong way to go (purely from a 'Calcium Oxalate levels in the final beer' perspective)?

I can live with less spinach and collards in my diet, but not beer.

Interestingly, the sheet my doctor gave me said meats were 'bad' but that University of Pittsburgh Med Center paper says meat is good (sardines and liver are 'moderate' but I don't eat either). Obv I tend to believe what I want to be true.

Maybe it's one of those: 'Well, eggs have cholesterol so obviously eating eggs is unhealthy' things that goes counter-intuitive to what seems obvious (but isn't).

I'm no expert on this certainly but I do know more about it than I ever hoped to. Yes, from the oxalate carry over POV low calcium is the wrong thing to do. I put more calcium into my Boh. Pils than I normally would for this reason.

As for the meat the idea there is that meat contains nucleotides (but, of course, so do plant cells) and that this leads to higher urea and that the urea can serve as a stimulator for stone formation. Indeed your "oxalate" stone(s) are probably about 10% uric acid. And yes, I have seen conflicting advice WRT to what one is advised to eat.

I thought one paper put it nicely. It said stone formation is perhaps 30% explainable by the thermodynamics, 25 percent explainable by ionic strength effects (I would roll this in with the thermo but I didn't write the paper) and the rest by as yet not understood phenomena. I look at it this way. The more dilute the solutions involved the less the liklihood of precipitation from any of those effects. If it comes out darker than 3 SRM or so I figure I haven't had enough water intake and work on that basis.

Based on my typ water intake (often next to none), I'm hoping just drinking more water will help. As of last night (well, two more tank flushes) I now have RO at my kitchen sink (separate faucet), I wonder if drinking that instead of regular tap will help?

If it comes out darker than 3 SRM or so I figure I haven't had enough water intake and work on that basis.

Click to expand...

I know another great beverage to get it under 3 SRM.

Yes, its BS. Having a relatively high calcium content in your brewing water will help precipitate oxalates from your beer.