The Basis of Low Oxygen Methodology

Let’s take the time machine and travel back to early 2014, where a guy (Brandon) and I exchanged beers. At the time, I was making what I thought of as “fantastic” beers that were falling flat when compared to genuine German examples. I had tried every trick in book to no avail. To my surprise, Brandon had the same issues going on. We were determined to figure it out. This included gathering others who had the same issues. Low and behold, after many test batches, we solved the problem.

The solution? Following the processes used by the large breweries whose beers we were trying to replicate. There have been many skeptics along the way. So as part of Low Oxygen Brewing’s (LOB) goals, the necessary resources and material were documented and provided for people (skeptics, geeks, the generally curious) to have at their disposal. I have spent the better part of 4 years, reading all these references, making contacts in the industry (name a large German Brewery, and I bet I have a contact), and even getting coursework and some schooling from a very prestigious German brewing school. That information is located on the website’s “List of Brewing References” page, as well as the many blog posts housed here on site.

We live in a day and age where, if we truly believe we are the most civilized and technologically advanced creatures ever to walk the earth, sticking your fingers in your ears and shouting is not an acceptable answer to documented technical and academic resources on brewing. Some of the staunchest and most vocal opponents of the topic either refuse to read any material about it or dismiss us with ad hominem attacks or accusations of some sort of religious style zealotry. ALL of our practices are not only referenced, they come from sound brewing science and is used as course material today in some of the world’s best brewing schools. We realize our stuff is geared towards homebrewers. We realize that these are advanced, and sometimes difficult, processes and procedures. However, just because one doesn’t want to put forth said effort, does not discount the methods. The methods and science are 100% sound. With that said, you will not reproduce larger German brewery beer characteristics using ANY standard homebrew methods in use today, this is a fact. Do we think that using these methods should be limited just to this pursuit? No, absolutely not, as we have had many people excel with these methods for Trappist style Pale and Dark ales, American Pale Ale, etc. The fact of the matter still stands, however, that if beers like Ayinger, Weihenstephaner, Augustiner, Bitburger, etc. are your goal from a flavor standpoint, then these methods are the only way to get there.

Now whether someone chooses to believe that or not is up to them. It however does not change the facts.

Low oxygen brewing in the homebrew world has ALWAYS BEEN the adaptation from professional to home. We don’t have the luxury of multi-million dollar specialized equipment. So these methods and procedures emulate professional teachings and practice with the tools we as homebrewers have. I hope this sheds some clarity on our reasoning and methods of this brewing process. What are the facts? Lets get to them.

Let us take for example a brewery by the name of Weihenstephaner (W), we should all be familiar with it. I am going to use it to compare that of low oxygen brewing methods.


It’s widely known, (and taught in school at W) that the brewery has an ion exchanger at one brewery, RO in the other. They then strip all oxygen with a vortex/o2-stripper. This helps them with fenton reactions and allows mashing with no oxygen content. Also, de-aeration equipment for liquor is standard in any moderately sized brewery because the DO has to be low at packaging, especially in export beers.

-Break Down-

Weihenstephaner- RO and Low DO water

Low Oxygen Brewing- We recommend RO water and some form of water dexoygenation (preboil or YOS). If you chose to use tap water, use BTB (this helps with fenton reactions, due to heavy metals in the tap water)

-Recap-

W is mashing with very little oxygen in the water, and we are mimicking this.


Polyphenols aid in increasing flavor stability, because of their reducing properties, so if they are oxidized it is not good. If the husks remain intact and you keep oxygen out, i.e. avoid hot side aeration, polyphenol oxidase cannot catalyse the oxidation reaction with such alacrity.

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Weihenstephaner- Has a very special mill that allows for them to mill the grain with this deoxygenated water (wet mill), thereby there is very little oxygen in this process as well. This specialized mill, this mill gets the perfect crush for extract and lauterability.

Low Oxygen Brewing – Recommends some grain conditioning, to help keep husks intact. This helps with extract and lauterability. We also advocate crushing grain very close to mash-in, which limits exposure to atmospheric oxygen.

-Recap-

W is crushing with very little oxygen, and while we can’t mimic this specifically, we can mimic the crush properties and limit oxygen exposure of crushed grain.


It is taught that gentle transfers of the beer and underletting (filling from the bottom) is the best and most gentle way to move water and wort. It also reduces splashing which results in oxygen pickup, thermal stress and sheer stress of the wort.

-Break Down-

Weihenstephaner- Fills all vessels from the bottom, avoids splashing and wort stresses

Low Oxygen Brewing – Recommends the same

-Recap-

 W is very conscious and careful of wort handling, and we mimic this as well.


It is taught in school that some breweries (hint nearly all German Macros) may even put a pillow of nitrogen over their grain bed in the lauter Tun. It’s so wide and shallow in non-British breweries that the wort can pick up a lot of o2. There is also professional talk of antioxidants. Narziß in Die mentions the use of antioxidants and Bamforth has played with them as well. There are also manufactures of chemical antioxidants to control HSA- namely AEB– . All this stuff is listed on the references page of the site, along with studies of the use of it… It is located in the Antioxidant section. AEB manufactures an oxidant called Anitoxin-SBT, it uses metabisulifte, ascorbic acid, and brewtanB.

-Break Down-

Weihenstephaner- purges all pipes with their low oxygen water, they purge vessels with n2. They have sealed vessels. They also have the square cube law on their side. In layman’s terms this means as a vessel size grows it’s volume (height) grows faster than its surface area. This matters because only the surface of the liquid (wort in this case) is potentially exposed.  

We modeled 3 vessels against one another, a standard Blichmann G2 Boilermaker 10 and 20 gallon kettle, and a Stout Tanks and Kettles 7bbl brew kettle, then used the scaling data from these 3 vessels to approximate the dimensions of a 200 hl (20,000 l) vessel similar to what is used at W. These are not the exact dimensions of the W kettle, but it serves to illustrate how much the volume increases versus the surface area.

Blichmann 10 gal. Boilermaker – Diameter = 13.9″, Height = 14.15″, Surface Area = 921 sq. in., Volume = 2,147 cu. in., V/A Ratio = 2.44:1

Blichmann 20 gal. Boilermaker – Diameter = 17.7″, Height = 20.7″, Surface Area = 1,643 sq. in., Volume = 5,093 cu. in., V/A Ratio = 3.1:1

Stout 7bbl – Diameter = 45.5″, Height = 76.5″, Surface Area = 14,187 sq. in., Volume = 124,386 cu. in., V/A Ratio = 8.77:1,

Scaled 200 hl – Diameter = 96.87″, Height = 160″, Surface Area = 63,436 sq. in., Volume = 1,179,323 cu. in., V/A Ratio = 19.1:1

When transitioning from the 10 gallon Blichmann to the 20 gallon Blichmann vessel, the surface area increases by a factor of 1.6 while the volume increases by a factor of 2.1. When transitioning from the 20 gallon Blichmann to the 7bbl Stout vessel, the surface area increases by a factor of 14 while the volume increases by a factor of 50. Finally, when transitioning from the 7bbl Stout vessel to the scaled 200 hl vessel,  the surface area increases by a factor of 63 while the volume increases by a factor of 495! So that means, a vessel that roughly approximates W’s shows a much lower surface area as opposed to the vessels that approximates the typical homebrew kettle setup.

Low Oxygen Brewing – Realizes that due to our surface area difference (as seen above, i.e. much more surface area, hence much more oxygen exposure), we recommend some form of a mash cap. This stops surface absorption of O2 (2ppm per hr). We also recommend some form of antioxidant, either SBT or camden tablets ( straight metabisulfite), due to most homebrewers not being able to have sealed vessels and/or N2 to purge with. With that said, personally with my new system do not use any form of antioxidant, I purge my vessels just like W.

Now I don’t know who is using antioxidants or SBT professionally, but I can assure you that if no one was, they would not be making it. However, you have to realize that using Metabisulfite, SBT, etc. as an anti-oxidant is a homebrew hack! We have never claimed this is a method used by large breweries, but rather a way for homebrewers to have active protection in addition to pre-boiling. It should also be noted: upon oxidation (i.e. post-pitching) they break down to either sodium and sulfate, or potassium and sulfate. They are then completely undetectable and harmless with no residual sulfites left in the wort. Some would argue they are even RHB compliant due to their nature. They could be used simply as water salts, and no one would be the wiser. But that’s a different discussion for a different day!

-Recap-

W realizes the effect of oxygen not only on the cold side, but the hot side of the brewery. The signature German flavor is made (really preserved) here, buy avoidance of oxygen. This is why it is stated above that using standard homebrew practices you will not be able to achieve this flavor, as these practices do not avoid oxygen pickup. We feel the same and mimic the avoidance as much as possible.


Commercial boil rates are much lower than in the homebrewing community. Thermal stress (TBI) is much less as well. In brewing schools, TBI (boil stress) is much talked about and new boiling systems are very popular. TBI has been shown to degrade the quality of finished beer. In the professional literature, they talk of how to measure and the optimal measurements.

-Break Down-

Weihenstephaner- Has a state of the art brewery, and the boiling system is no different. Minimal evaporation loss and TBI pickup.

Low Oxygen Brewing- Recommends a lid partially covered, this allows the evaporation to be substantially lowered, and due to that, you can turn the power down. This allows for less thermal loading of the wort.

-Recap-

W tries to limit wort stress and boil off, we mimic this as well.


Trub and its various elements (hot break, cold break, hops, etc) has long been known, as referenced in and by a plethora of technical (professional breweries) and academic (brewing schools and researchers) studies to be negative to beer. It is taught that hot break and hop matter should be absent in wort. If not using an assimilation yeast, then a little bit of cold break CAN be desired.

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Weihenstephaner- Uses an assimulation yeast, therefore transfers bright beer to the tank.

Low Oxygen Brewing- Recommends a nice whirlpool, and short sedimentation time. Clear wort, to the fermenter, with just enough cold break.

-Recap-

W realizes the potential impact of trub and fatty matter in the wort. It has been proven to lead to a degradation beer flavor, to accelerated staling, etc. We mimic this as well.


Pitch rate and Fermentation. Pretty standard practice, we pitch at commercial rates and ferment cold.


Spunding for carbonation. Cold side oxidation starts when fermentation is done. Professionals have specialized equipment and a seemly endless supply of co2. They can purge a brite tank for 8hrs, and measure DO with some very expensive equipment.

-Break Down-

Weihenstephaner- Is going to cap the tanks, it’s standard practice. Anytime beer is moved it will be with low DO water pre purge and or n2/co2. SUPER low DO numbers, as it has to be for shelf life and exports. Also force carbonation can only happen with re-captured co2 equipment due to the RHB, which they have, and use.

Low Oxygen Brewing- Recommends spunding. Normally folks don’t have pressure capable fermenters, or low DO water around to push beer, Our co² purity is usually much lower. It’s the only way we can get commercial DO values.

-Recap-

W realizes the utmost importance to cold side DO numbers, we mimic this as well. 

 

This should hit on most of all important steps in the process of Low Oxygen Brewing.