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LODO - The Return oF HSA - Printable Version

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LODO - The Return oF HSA - ArrogantBastardAle - 06-22-2016

The German Brewing Forum came up with a technique that they say makes a huge difference in their beer.  They claim that they are getting true German tasting beers with this method.  Essentially, they argue that hot side aeration occurs during the mash.  They document a process they call "Low Dissolved Oxygen" brewing where the mash water is boiled before hand to remove oxygen, and a small amount of sodium metabisulfite is added to prevent oxygen from dissolving into the water.  There are quite a few other steps that they say reduce HSA, so I won't list the other .  They argue that most HSA tests don't take into account the oxidation that occurs during the mashing process.

Although I will probably never try it, this is super interesting to me.  The paper did have some references to German science texts (Narziss and Kunze), but did not go into great length as far as providing sources for particular claims or data points.  Despite this, it was interesting enough to bring Kai Troester out of hiding: http://braukaiser.com/blog/blog/2016/04/30/low-oxygen-brewing/

Here is the write up: http://www.germanbrewing.net/docs/Brewing-Bavarian-Helles.pdf

Apparently, there has been some amount of drama on their forum regarding the legitimacy of the claims from a scientific point of view.  Theoretical discussions seem to have halted due to these arguments, with threads ending with "Just try it for yourself."  Despite this, there has been a recent write up on the science of these claims from a guy that goes by "uberg33k" on the BrewUnited Forums and Reddit (he appears to be a neutral person with a strong science background): http://immaculatebrewery.com/oxygen-and-mashing/

Matt Chrispen from Accidentalis Brewing Blog recently wrote about his experience of LODO.  I have met Matt, and have read a bit of his blog.  He's definitely a smart homebrewer whose opinion I take seriously: http://accidentalis.com/low-oxygen-brewing-exploring-lodo-method/.  He's established a relationship with these German Brewing Forum guys, so I think he might be a little biased, but I believe that he is being truthful about the results he is getting.

Lastly, here is a guy from the German Brewing Forum who brews live on Youtube: https://www.youtube.com/user/rabeb25/videos (these are live streams, so the videos are very long).

Anyway, I find these claims interesting.  As mentioned above, my equipment does not allow me to easily pursue this method myself (and I don't brew German style beers).  I know Tony Yates has shown some interest, but also seemed too skeptical to perhaps try it himself (maybe he changed his mind after seeing some of the new blog write ups about LODO).  If I am curious about this method though, I assume others will be as well, hence this post.  If you do choose to try this method, please let us know how the results turn out.

Cheers,
Dan


RE: LODO - The Return oF HSA - LLTV - 06-22-2016

That's some pretty interesting reading. Thanks for posting it Dan.


RE: LODO - The Return oF HSA - Mainebrewguy - 06-22-2016

Dan, I probably wont have time to dig into this right away but this has always been a subject i believed in however I thought that the boil would undo any harm in the mash with reference to HSA. What specifically is the reaction that happens in the mash that is not being un-done in the boil? In the military we call this the BLUF (bottom line up front).

Thanks for posting this info.


RE: LODO - The Return oF HSA - ArrogantBastardAle - 06-22-2016

(06-22-2016, 03:47 PM)Mainebrewguy Wrote: Dan, I probably wont have time to dig into this right away but this has always been a subject i believed in however I thought that the boil would undo any harm in the mash with reference to HSA. What specifically is the reaction that happens in the mash that is not being un-done in the boil? In the military we call this the BLUF (bottom line up front).

Thanks for posting this info.

The German Brewing Forum PDF has a fairly unspecific explanation:

"There is far more to HSO than the formation of trans-2-nonenal precursors typically associated with a “cardboard” flavor. In fact, HSO should be thought of as both the loss of malt flavors, as well as the creation of staling compounds. Oxygen can react with a great number of compounds in wort, including aromatic malt phenols. These compounds posses fresh, pleasant flavors and aromas on their own, but upon oxidation they quickly polymerize to form bitter tasting polyphenols and tannins [3]. Oxygen can also react with Maillard products from darker malts (such as caramel malt), altering their flavors by muting them or making them cloying. Unfortunately, copper, iron, zinc and manganese will accelerate the oxidization of malt compounds, and must be eliminated from the brewing system altogether. "

More specific information is in Uberg33k's write up where he discusses the enzymes that create the browning that we see in things like fruit that sits out too long (he also argues against some of the statements above).  Heat alone won't reverse these reactions; in fact boiling will denature these enzymes so the reactions cannot be enzymatically reversed, and 100°C is probably not hot enough to change the molecules without enzymes (I think):

"On page 4, lipoxygenase (LOX) and peroxidase enzymes are mentioned. I find this interesting because this is a class of enzymes we as brewers will typically glaze over. Along with superoxide dismutase (SOD) and polyphenol oxidase (PPO), they comprise most of what we'd think of as enzymatic browning reactions. You'd commonly see this happen in apples, potatoes, avocados, and just about any other fruit or vegetable after they've been cut and exposed to air. What effect do these enzymes have on beer? Actually, it isn't well studied. It is known that there's a correlation to LOX activity and trans-2-nonenal formation which would be the cardboard staling flavor beer can get7, but that's about it. With the exception of PPO, these enzymes actually increase in concentration during the malting process, but most of them are inactivated early on in the mash8. However, there are two interesting pieces of information to be had: peroxidase survives in all but the highest mash temperatures and PPO is present in low kiln malt, but not higher kilned malts. I find that last point especially interesting. PPO can act on polyphenols to produce benzoquinones9, which then react to form other flavor active quinones. The reason that's interesting is that benzoquinone can take a form that tastes dirty, like pencil shavings10. Engage in a bit of a thought experiment with me for a second. Imagine what you and I normally think of as an all-pils wort straight out of the mash tun. It has a sweet grainy flavor, but can sometimes take on a husk forward, earthy note. If you subtracted the flavor of pencil shavings from the flavor of pilsner wort, how would it taste? Most of the descriptors I come up with seem to fall in line with the way people from the GBF describe their wort. It's my hypothesis that it isn't something being lost, but rather additional flavor being gained by the oxidation of polyphenols due to the action of PPO and possibly the action of peroxidase. This might explain why GBF members detect a difference in some of their beer while a vast majority of brewers have never noticed oxidation effects in their beer; your average American 2-row is kilned and processed to the point where there is no PPO left as are most other malts. Continental pilsner, which would be used in most German recipes, is not processed that highly and would contain some PPO. Step mashing would also mean the temperature is kept lower for longer periods of time, which allows PPO and peroxidase to act longer before denaturing. Some of trials done by forum members indicated a reddish tone to non-SMB'ed controls suggesting that catalase might also play a role in mash oxidation 8."


RE: LODO - The Return oF HSA - ArrogantBastardAle - 07-20-2016

I've been reading through this thread, which has some great insights from highly educated brewing scientists: http://www.homebrewtalk.com/showthread.php?t=580532


RE: LODO - The Return oF HSA - Mainebrewguy - 07-23-2016

Hi Dan that thread is pretty impressive, seems that a lot of urban legends are true?? Or at least being revisited again. some interesting new thoughts on O2 additions after pitching the yeast, on bottom fermenting yeasts


RE: LODO - The Return oF HSA - Mainebrewguy - 07-23-2016

I like this summary of points quoted off of HBT

A summary of the main points:

Hot Side Oxygenation is actually a big deal, but happens so early in the brewing process that homebrewers didn't know how to prevent it.
Copper increases oxidation, so throw out your copper chillers.
Grind grain slightly damp so the husks stay intact. Mill immediately before mashing.
Degas your mash water by boiling it, then add sulfite in fairly large doses (100 mg/l; a Campden tablet is 440mg).
Chill to mash in temperature.
Infuse with minimal stirring, by underletting if possible. If your grain floats it's trapping too much air.
Cover the mash tun during the mash.
Treat sparge water similarly (a bit less sulfite) to mash water, or use no-sparge.
Expect lower mash pH and higher sulfate due to the sulfite scavenging O2.
Boil at a high simmer rather than a rolling boil.
Pitch before oxygenating.
Keg in a CO2-purged keg before primary is complete. Keep headspace to a minimum and put a pressure relief on the keg. Allow some yeast transfer.
If you re-keg or bottle purge and allow yeast transfer, consider adding sulfite as well. For bottling the easiest is to krausen and counter-pressure fill. For re-kegging the easiest is – don't.


RE: LODO - The Return oF HSA - ArrogantBastardAle - 10-20-2016

Sounds about right.  Mike Tonsmeire recently posted about his experience.  They suggest also doing No Sparge so as to avoid HSA during sparging, and if you do that you need to use a lower amount of MBS (55mg/L): http://www.themadfermentationist.com/2016/10/low-dissolved-oxygen-do-brewing-lager.html

Gary, if you try it, please make a video!


RE: LODO - The Return oF HSA - ArrogantBastardAle - 12-08-2016

More links on LODO.

A how-to guide from Matt Crispen: http://accidentalis.com/practical-guide-low-oxygen-brewing-on-the-brew-magic/

An interview with Bryan Rabe on Fermentation Nation podcast.  This interview discusses some of the more basic ways to achieve LODO brewing.  For example, instead of boiling your strike water, you can add a small amount of sugar and bread yeast to the water and let the yeast consume the O2 in the strike water.  If I was more interested in brewing German beers, I would try it: http://fermentationnation.net/2016/11/episode-43-low-oxygen-brewing-with-bryan-rabe/


RE: LODO - The Return oF HSA - ArrogantBastardAle - 01-11-2017

An interview with a German LODO homebrewer who has been winning NHC metals with this process, and how he uses sugar and yeast to remove O2 from the strike water: http://accidentalis.com/brewing-with-a-master-ricardo-fritzsche/

I am posting these links for my own reference, but maybe someone else will find them useful. Smile