Oxygen and Mashing (Immaculate Brewery blog)

[lupulus]

I read with great interest the posting about Oxygen and Mashing by the Immaculate Brewer and I would like to comment on it from the perspective of an avid brewer/ learner without a bias for or against the LODO paper.
GENERAL COMMENT
It seems that many bloggers/ brewers attempt to challenge the paper as if it were an original method. Maybe most people interpret it this way; I do not. My interpretation of the paper is that the GBF team is hypothesizing that HSO does occur at a homebrew scale, and proposes a process to prevent it.
SPECIFIC COMMENTS
1. IB: " ...The fundamental argument boils down to "it works, trust us" with no supporting evidence..." On the contrary, there are many papers about mashing HSO and Kúnze among others strongly recommends taking steps to avoid it. I would agree that currently there is no clear evidence (that I know of) that mashing HSO at the homebrew level affects the final beer, but the hypothesis has a solid base, and this must be recognized.
2. The suggestion of the Immaculate Brewer to start a mash at the acid rest level to inhibit the PPO enzyme is not aligned with the LODO principles. LODO calls for a mash start at a relatively high temperature to minimize the effect of LOX.
3. The suggestion of IB to use sauergut as a reducer is also incompatible with LODO because as indicated above, mash is to start at a high temperature (about 63C). Of course, the use of sauergut for pH adjustments is strongly recommended and used by all Reinheitsgebot brewers.

In summary, it is clear that the comments are thoughtful and well-intended, but they can lead some readers to test this hypothesis with processes not based in the original LODO principles. In other words, you do not have to follow the method outlined in the paper, but in this case, you have to go to the source (eg Kúnze) and adapt the process considering all the variables outlined (in Künze).

Cheers,

[Bryan R]

Your general comment is pretty spot on.

I just wish people could actually follow the paper and give a proper reviewal. Everyone is adding their own personal "flair" and IMO that deems it null.

[mchrispen]

Gary can defend himself, but to discount a chemist's view of what is going on with LODO and looking at the particular reactions from that perspective (as opposed to a brewer's perspective) seems a bit myopic. His findings don't discount LODO in any way, rather speculate on the actual impact of sulfites and low oxygen in the mash.

I read the paper to say to keep the mashing period as short as possible to avoid exposure to atmospheric oxygen (and other potential oxidizers, such as hydroxides that form in the mash) - which Gary doesn't address. The PPO comments were contextually made in reference to the sulfite interference of PPO, SOD, and LOX, and their potentially bad effects, and there is ample evidence that a short protein rest reduces PPO. The paper references using malt conditioning, which also inhibits the formation of these compounds. The rest is musing through procedures that may or may not have alternative benefits.

Bryan - I agree, but there is a house of cards argument to be made. It took you and the team years to perfect your technique and methods, and testing this in a manner that doesn't drift from the paper directly (and open up the *valid* argument) will take iteration and refinement. I am struggling with getting A/B batches that match up - and have thrown out 4 batches now that either measured poorly or hit some other technical issue that would disqualify it. While I am convinced that LODO is a positive technique at this point - it will take more than someone on a stump shouting the gospel of LODO for the larger community. My perspective has been how to accomplish this with my system, and to reduce the SMB dosage to match. If people want to mock me (and they have) about trying to perfect this - I really don't care. I care about what is in the glass. Understanding why is simply part of my lizard brain struggling.

A few positive triangle tests with data should add credibility to the paper. And I understand Brandon maybe having some discussions with Prof. Barth who wrote the book, "Chemistry of Beer." I am reading through his book right now, and find it fascinating, and written in a way that I can just grasp. I spoke briefly with him at HomebrewCon, and he is quite interested in AND very supportive of low oxygen brewing. It would be nice to isolate what specifically is happening.

[Bryan R]

You guys and your blind triangle testings
Here is your blind test, can you taste the difference between a german beer and an American made supposed german beer from an american brewery? If yes, they are brewed using low oxygen methods, its no secret and every German brewmaster will tell you so. So make that happen on a homebrew scale, thats it, and thats all.

[Techbrau]

I am happy that people like uberg33k and mchrispen (and others as well, like Brian Bergquist) are taking the time to help get the ball rolling on a serious conversation about the role of oxygen in brewing. It's a complex issue that hasn't gotten the attention it deserves from the craft/home brewing community and I think anybody who discusses or posts about it thoughtfully and with an open mind is doing a good service for the community.

This is slightly unrelated, but I just got back from a trip to Germany as was lucky enough to be able to spend some time with a pro brewer friend of mine there. I asked him what the main factors you have to consider are when going from brewing a typical craft ale to a beer like Edelstoff, and I kid you not, the very first thing he said was "well, to start you need to use degassed water." I hadn't even mentioned anything to him about low oxygen brewing at this point in the conversation. I asked him if low oxygen brewing was common knowledge in Germany and he said that anybody who goes to brewing school knows about it, and that in a brewery setting it all comes down to how well the oxygen controls are implemented in practice. Some do it better than others, but he confirmed that DO is routinely measured and recorded in most everybody's brew logs along with everything else like gravity, color, turbidity, etc. They keep it as low as possible.

I'm not sure where the idea that HSA matters at commercial scale but doesn't matter at homebrew scale came from. I can't think of a physical explaination for why that would be. I can, however, think of a physical explaination for why HSA happens much more readily at the homebrew scale.

If you're brewing 1,000 hl, you benefit from a dramatically reduced surface area to volume ratio thanks to the square-cube law. Specifically, this ratio is about 20 times smaller than a homebrewer's system (the exact ratio will depend on vessel geometry). This is equivalent to us keeping an invisible mash cap covering 95% or more of the wort surface in place through the entire brewing process. It is also standard practice at large scale to mill under inert gas (this is extremely important to prevent explosions), and for the malt to go through a piping system directly from steam conditioning to milling to non-aerating dough-in with a vormaischer (basically a device which injects water into the delivery pipe containing the milled grist and inert gas mixture) before being pumped into the tun.

This means that the malt is conditioned, milled, and mixed into degassed water with virtually no oxygen pickup. Subsequently, the tiny surface area to volume ratio of a commercial system, combined with pumping from below, means that oxygen diffusion into the wort from the atmosphere will be minimal (although Kunze explicitly states multiple times that ideally nitrogen is blown into the vessels). There are other methods used to keep oxygen in check (like the Shakesbeer device), but the system I described is basically all you need to do to achieve Lodo at large scale. It's also easy to see how a bit of wort splashing could quickly mess all of that up.

A lot of the criticism I've seen of our Lodo process (not from Gary or Matt) revolves around the fact that German pros don't use SMB. If you followed my example above, you'd understand why they don't need to. However, what are you going to do as a homebrewer who doesn't mill under inert gas, doesn't own a packed column capable of degassing water down to 0.01 ppm DO, doesn't dough-in with a non-aerating vormaischer, and has to deal with oxygen diffusing into the wort 20 times faster (or more) than it does in a commercial system? SMB is our crutch.

[Kit_B]

[mchrispen]

Bryan - I can and have. But that is anecdotal and not proof. Like I said, I care less about what people think and more about what is in the glass.

The triangle is the accepted citizen science and has more holes than a sponge the way it is interpreted. But, it does bring some unbiased data point to the discussion.

I think there are a few folks that are credited with saying that HSA is not a Homebrew problem - which I think ties to the RDWHAHB mantra. Fine for the casual brewer - but I am not that person. I am happy to sweat and bleed if I see progress.

To be fair - the tossed batches are efficiency problems, not LODO problems. But showed in doing LODO batches. Has to be the crush.




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[Bryan R]

I have nothing to prove to anyone, I am happy to have others claim it's confirmation bias. I will not be changing my processes and will enjoy my conformation biased glorious Helles for entirety.

[mchrispen]

I respect that Bryan, as well as the work involved to get here, and sharing the process with the world. I hope none of my comments were taken as insult or criticism.

I am convinced, just want to understand the underlying chemistry and add to the conversation. I was raised to have a critical mind and question everything. It's a process.

I wouldn't be considering tossing out all of my equipment to build a new automated system to brew inside (and electric) engineered for low oxygen sensibility if I wasn't positive. I just need to find a new job to pay for it

[Brandon]