[techbrau]

I'll be curious to see where this discussion goes after people listen to what Joe has to say on today's podcast.

I gave it a listen. It's interesting to get his take on Brewtan B, and while most of what he said is technically correct, it's incorrect to conclude that Brewtan B prevents oxygen from reacting in the mash/boil altogether. I actually noticed that Joe hedged a bit on this - he said oxygen wouldn't react in the same way it normally would. He didn't say it wouldn't react at all.

Oxygen has more than one pathway to react with stuff in the mash. The Fenton reaction is only one of these pathways. Another set of major oxidative pathways are through naturally occurring enzymes found in the malt, such as lipoxygenase and polyphenol oxidase. I think polyphenol oxidase is the real bogeyman here, because we hypothesize that the simple, low molecular weight malt phenols are the main source of the fresh malt "it" flavor, and polyphenol oxidase is specifically made for catalyzing the oxidation of those phenols.

To use an analogy:

Using Brewtan B in oxygen-saturated water and expecting zero oxidation to take place is like mashing at 160 F and expecting no starch conversion to take place because you've denatured beta amylase at that temperature. It doesn't work, because you've overlooked the fact that alpha amylase is still active at 160 F and provides another pathway for the starch to convert.



This is a side-by-side picture of wort produced with a normal process (on the left) and wort made with the low-oxygen process (on the right). The color difference is indicative of the fact that the polyphenol oxidase enzyme has been inhibited. When polyphenol oxidase (which is the same type of enzyme that turns sliced apples or avocados brown when exposed to air) oxidizes the malt phenols into quinones, they polymerize to form reddish-brown polyphenols. The fresh malt flavors of the phenols disappear, and are replaced by a bitter malt flavor (George Fix called this "herbstoffe").

If Brewtan B doesn't make the wort several shades lighter (like the picture above), then it's not blocking all oxidative reactions in the mash.

I think that Brewtan B could absolutely be a useful tool, and i see it helping more post-fermentation because the Fenton reaction is also a big oxidative pathway in finished beer. So it could definitely help with shelf stability there - but I don't see how it can possibly be a magic bullet all by itself. Note that other commonly used additives like gelatin and Irish moss can also have metal chelating properties.

[Big Monk]

Tech replied with a much more thorough assessment than I could have mustered (I was typing before I read it) and I think his comments as well as Bryan's show why Brewtan alone cannot supplant Low O2 brewing should one desire to pursue those methods.

But like he said, that is not to say it isn't a useful tool to have in your arsenal if you aren't already using methods that make it unnecessary.

[beersk]

Tech replied with a much more thorough assessment than I could have mustered (I was typing before I read it) and I think his comments as well as Bryan's show why Brewtan alone cannot supplant Low O2 brewing should one desire to pursue those methods.

But like he said, that is not to say it isn't a useful tool to have in your arsenal if you aren't already using methods that make it unnecessary.

I do think, however, that Brewtan B, in conjunction to low O2 brewing could be a very good thing.

[hopfenundmalz]

I had a thread on that a while back. Read these.
https://beersensoryscience.wordpress.com/2010/11/15/chemistry-of-beer-aging/
http://depa.fquim.unam.mx/amyd/archivero/ARTICULOGRUPO8_25527.pdf

[HoosierBrew]

I had a thread on that a while back. Read these.
https://beersensoryscience.wordpress.com/2010/11/15/chemistry-of-beer-aging/
http://depa.fquim.unam.mx/amyd/archivero/ARTICULOGRUPO8_25527.pdf

This is something I missed the first time around:

" Even (E)-2-nonenal, a compound long suspected to be the main cause of oxidized flavour, paradoxically appears to arise by non-oxidative mechanisms in beer. This explains why staling is possible in the absence of oxygen. On the other hand, although some compounds result from oxidation reactions, it is at present not really clear which compound(s) is/are responsible for the oxidation off-flavour of beer."


 Obviously reducing O2 is a desireable goal in brewing, but clearly the whole process is not cut and dried, or completely understood. Thanks for re-posting.

[The Beerery]

Actually kunze speaks to this. There are compounds that you can't stop from reacting even in the absence of oxygen.  That's why even the the big boys can't make beer keep forever. However they do target 9 months for shelf stability.  Which is nothing short of amazing.


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[narvin]

I'll be curious to see where this discussion goes after people listen to what Joe has to say on today's podcast.

I gave it a listen. It's interesting to get his take on Brewtan B, and while most of what he said is technically correct, it's incorrect to conclude that Brewtan B prevents oxygen from reacting in the mash/boil altogether. I actually noticed that Joe hedged a bit on this - he said oxygen wouldn't react in the same way it normally would. He didn't say it wouldn't react at all.

Oxygen has more than one pathway to react with stuff in the mash. The Fenton reaction is only one of these pathways. Another set of major oxidative pathways are through naturally occurring enzymes found in the malt, such as lipoxygenase and polyphenol oxidase. I think polyphenol oxidase is the real bogeyman here, because we hypothesize that the simple, low molecular weight malt phenols are the main source of the fresh malt "it" flavor, and polyphenol oxidase is specifically made for catalyzing the oxidation of those phenols.

To use an analogy:

Using Brewtan B in oxygen-saturated water and expecting zero oxidation to take place is like mashing at 160 F and expecting no starch conversion to take place because you've denatured beta amylase at that temperature. It doesn't work, because you've overlooked the fact that alpha amylase is still active at 160 F and provides another pathway for the starch to convert.



This is a side-by-side picture of wort produced with a normal process (on the left) and wort made with the low-oxygen process (on the right). The color difference is indicative of the fact that the polyphenol oxidase enzyme has been inhibited. When polyphenol oxidase (which is the same type of enzyme that turns sliced apples or avocados brown when exposed to air) oxidizes the malt phenols into quinones, they polymerize to form reddish-brown polyphenols. The fresh malt flavors of the phenols disappear, and are replaced by a bitter malt flavor (George Fix called this "herbstoffe").

If Brewtan B doesn't make the wort several shades lighter (like the picture above), then it's not blocking all oxidative reactions in the mash.

I think that Brewtan B could absolutely be a useful tool, and i see it helping more post-fermentation because the Fenton reaction is also a big oxidative pathway in finished beer. So it could definitely help with shelf stability there - but I don't see how it can possibly be a magic bullet all by it

Uh, your "scientific paper" also said that using metabisulfite resulted in lowering the wort pH by 0.1.  This would also have a major effect on wort darkening.  It's also possible that maillard reactions are inhibited through other pathways, independent of the results you claim.

We all believe in minimizing oxygen.  However your claims are approaching snake oil at this point.  Analogies have no place in science, but they do in politics and cults.

[Stevie]

Narvin, some of the claims regarding Brewtan B have as well. I'm still willing to try it, but I'm skeptical of the magic bullet approach.

[Big Monk]

I'll be curious to see where this discussion goes after people listen to what Joe has to say on today's podcast.

I gave it a listen. It's interesting to get his take on Brewtan B, and while most of what he said is technically correct, it's incorrect to conclude that Brewtan B prevents oxygen from reacting in the mash/boil altogether. I actually noticed that Joe hedged a bit on this - he said oxygen wouldn't react in the same way it normally would. He didn't say it wouldn't react at all.

Oxygen has more than one pathway to react with stuff in the mash. The Fenton reaction is only one of these pathways. Another set of major oxidative pathways are through naturally occurring enzymes found in the malt, such as lipoxygenase and polyphenol oxidase. I think polyphenol oxidase is the real bogeyman here, because we hypothesize that the simple, low molecular weight malt phenols are the main source of the fresh malt "it" flavor, and polyphenol oxidase is specifically made for catalyzing the oxidation of those phenols.

To use an analogy:

Using Brewtan B in oxygen-saturated water and expecting zero oxidation to take place is like mashing at 160 F and expecting no starch conversion to take place because you've denatured beta amylase at that temperature. It doesn't work, because you've overlooked the fact that alpha amylase is still active at 160 F and provides another pathway for the starch to convert.



This is a side-by-side picture of wort produced with a normal process (on the left) and wort made with the low-oxygen process (on the right). The color difference is indicative of the fact that the polyphenol oxidase enzyme has been inhibited. When polyphenol oxidase (which is the same type of enzyme that turns sliced apples or avocados brown when exposed to air) oxidizes the malt phenols into quinones, they polymerize to form reddish-brown polyphenols. The fresh malt flavors of the phenols disappear, and are replaced by a bitter malt flavor (George Fix called this "herbstoffe").

If Brewtan B doesn't make the wort several shades lighter (like the picture above), then it's not blocking all oxidative reactions in the mash.

I think that Brewtan B could absolutely be a useful tool, and i see it helping more post-fermentation because the Fenton reaction is also a big oxidative pathway in finished beer. So it could definitely help with shelf stability there - but I don't see how it can possibly be a magic bullet all by it

Uh, your "scientific paper" also said that using metabisulfite resulted in lowering the wort pH by 0.1.  This would also have a major effect on wort darkening.  It's also possible that maillard reactions are inhibited through other pathways, independent of the results you claim.

We all believe in minimizing oxygen.  However your claims are approaching snake oil at this point.  Analogies have no place in science, but they do in politics and cults.

You would just account for the pH drop in your pH estimation, i.e. Reduce your pH by the amount that corresponds to the SMB dose rate.

All the sources from the GBF paper are readily available. Myriad additional sources justifying the methods detailed within it are also available.

Analogies are useful for relating complex or abstract ideas in a way that drives the point home.

[troybinso]

I'll be curious to see where this discussion goes after people listen to what Joe has to say on today's podcast.

I gave it a listen. It's interesting to get his take on Brewtan B, and while most of what he said is technically correct, it's incorrect to conclude that Brewtan B prevents oxygen from reacting in the mash/boil altogether. I actually noticed that Joe hedged a bit on this - he said oxygen wouldn't react in the same way it normally would. He didn't say it wouldn't react at all.

Oxygen has more than one pathway to react with stuff in the mash. The Fenton reaction is only one of these pathways. Another set of major oxidative pathways are through naturally occurring enzymes found in the malt, such as lipoxygenase and polyphenol oxidase. I think polyphenol oxidase is the real bogeyman here, because we hypothesize that the simple, low molecular weight malt phenols are the main source of the fresh malt "it" flavor, and polyphenol oxidase is specifically made for catalyzing the oxidation of those phenols.

To use an analogy:

Using Brewtan B in oxygen-saturated water and expecting zero oxidation to take place is like mashing at 160 F and expecting no starch conversion to take place because you've denatured beta amylase at that temperature. It doesn't work, because you've overlooked the fact that alpha amylase is still active at 160 F and provides another pathway for the starch to convert.



This is a side-by-side picture of wort produced with a normal process (on the left) and wort made with the low-oxygen process (on the right). The color difference is indicative of the fact that the polyphenol oxidase enzyme has been inhibited. When polyphenol oxidase (which is the same type of enzyme that turns sliced apples or avocados brown when exposed to air) oxidizes the malt phenols into quinones, they polymerize to form reddish-brown polyphenols. The fresh malt flavors of the phenols disappear, and are replaced by a bitter malt flavor (George Fix called this "herbstoffe").

If Brewtan B doesn't make the wort several shades lighter (like the picture above), then it's not blocking all oxidative reactions in the mash.

I think that Brewtan B could absolutely be a useful tool, and i see it helping more post-fermentation because the Fenton reaction is also a big oxidative pathway in finished beer. So it could definitely help with shelf stability there - but I don't see how it can possibly be a magic bullet all by itself. Note that other commonly used additives like gelatin and Irish moss can also have metal chelating properties.

The image of those two glasses of wort clearly shows a difference in color. Can you elaborate on the specific differences between the process of producing each batch of wort?

Sent from my SM-G930P using Tapatalk

[homoeccentricus]

Edit: Removed the nugget due to poor attitudes.

https://www.flickr.com/photos/ianlayzellphotographs/3977042044

Maybe we need a group hug?

[natebriscoe]

I'll be curious to see where this discussion goes after people listen to what Joe has to say on today's podcast.

I gave it a listen. It's interesting to get his take on Brewtan B, and while most of what he said is technically correct, it's incorrect to conclude that Brewtan B prevents oxygen from reacting in the mash/boil altogether. I actually noticed that Joe hedged a bit on this - he said oxygen wouldn't react in the same way it normally would. He didn't say it wouldn't react at all.

Oxygen has more than one pathway to react with stuff in the mash. The Fenton reaction is only one of these pathways. Another set of major oxidative pathways are through naturally occurring enzymes found in the malt, such as lipoxygenase and polyphenol oxidase. I think polyphenol oxidase is the real bogeyman here, because we hypothesize that the simple, low molecular weight malt phenols are the main source of the fresh malt "it" flavor, and polyphenol oxidase is specifically made for catalyzing the oxidation of those phenols.

To use an analogy:

Using Brewtan B in oxygen-saturated water and expecting zero oxidation to take place is like mashing at 160 F and expecting no starch conversion to take place because you've denatured beta amylase at that temperature. It doesn't work, because you've overlooked the fact that alpha amylase is still active at 160 F and provides another pathway for the starch to convert.



This is a side-by-side picture of wort produced with a normal process (on the left) and wort made with the low-oxygen process (on the right). The color difference is indicative of the fact that the polyphenol oxidase enzyme has been inhibited. When polyphenol oxidase (which is the same type of enzyme that turns sliced apples or avocados brown when exposed to air) oxidizes the malt phenols into quinones, they polymerize to form reddish-brown polyphenols. The fresh malt flavors of the phenols disappear, and are replaced by a bitter malt flavor (George Fix called this "herbstoffe").

If Brewtan B doesn't make the wort several shades lighter (like the picture above), then it's not blocking all oxidative reactions in the mash.

I think that Brewtan B could absolutely be a useful tool, and i see it helping more post-fermentation because the Fenton reaction is also a big oxidative pathway in finished beer. So it could definitely help with shelf stability there - but I don't see how it can possibly be a magic bullet all by itself. Note that other commonly used additives like gelatin and Irish moss can also have metal chelating properties.

The image of those two glasses of wort clearly shows a difference in color. Can you elaborate on the specific differences between the process of producing each batch of wort?

Sent from my SM-G930P using Tapatalk

One wort was made with low o2 mashing procedures (light), the other was standard homebrewing procedures(dark).
The differences at that stage would be preboiled water and smb.

[natebriscoe]

Edit: Removed the nugget due to poor attitudes.

https://www.flickr.com/photos/ianlayzellphotographs/3977042044

Maybe we need a group hug?

No kidding. Just when I thought everyone was going to start getting along again.

[dmtaylor]

Maybe we need a group hug?

No, this is how we have fun on the interwebs.   

Nugget removed.... that's funny right there. 

[Big Monk]

Edit: Removed the nugget due to poor attitudes.

https://www.flickr.com/photos/ianlayzellphotographs/3977042044

Maybe we need a group hug?

No kidding. Just when I thought everyone was going to start getting along again.

Don't make a problem where one doesn't exist. There is the opportunity for some useful dialogue here, and if we start making comments like this the conversation will go south.