[erockrph]

Maybe I’m wrong here, but from what I understand, oxidation in the mash is caused by O2 reacting with divalent cations (manganese, magnesium, zinc — cations with valence of 2+) to create superoxide, free radicals. 

Problem is once those oxidation reactions occur, the compounds created continue all the way thru to the packaged beer.

The Low O2 guys (I believe) have taken the approach to reduce/eliminate dissolved O2 in the mash thru use of sulfur based compounds, mash caps, etc.

Instead of focusing on reducing/elimination of O2, (which is kinda hard to do since it surrounds us), I think time is better spent focusing on the reaction.

I believe by using heavy metal chelators that can trap the divalent cations, you can reduce and possibly eliminate the reaction of mash oxidation.

In my opinion, you have a better chance on winning the reaction battle than the O2 battle short of a room filled with inert gas and wearing a space suit.

In the food world FDA approved EDTA does this. I think Brewtan B does as well (maybe Joe can confirm). I’ll report back on what Joe says from the note I sent him.

I add 1/2 tsp of hydrated Brewtan B directly to the mash after mash in, wait a minute, then add 1 tsp CaCl or Gypsum directly to the mash and focus on pH. The wait is so the Brewtan B is not binding with my Calcium (if that’s a thing).

After the mash danger is over, transferring hot wort quietly to the BK, boiling, cooling quickly and pitching plenty of healthy yeast, closed transfer to a purged keg as soon as fermentation is complete, and keeping the beer cold are all considered by some to be best practices.

Even closed xfer we pick up O2. It’s just inevitable and we do what we can. The rest is just the price of doing business.

I add gallotannin to my strike water and it has made a big difference in my beer. My well water has a fair amount of manganese and a bit of iron. Before using the gallotannin my beer always had a faint metallic taste that I could pick out if I looked for it. Nothing horrible, but I could tell it was there. That went away,  but the bigger change was how much fresher the malt character tasted. The best way I can describe it is that before using the gallotannin my beer tasted like "a beer that was brewed with malt X", but now it tastes exactly like that specific malt as it tasted and smelled on brew day. More of the malt flavor carries through to the finished beer.

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[majorvices]

I was using BtB at YH before i ever even saw it mentioned by the LoDo folks thanks to a recommendation from my chemical guy at Loeffler. Used to use it in the mash and the kettle followed by a hot centrifuge which removed all the break material - strong fermentation, etc., even experimented with sodium metabisulphite in the BBT - managed to get the beer under 10 PPB DO. Was doing some serious stuff to preserve shelf life, some of the stuff along the same lines as the LoDo I suppose. Was not able to naturally carbonate due to many reasons, running carbbed beer through cold centrifuge would have been one for sure (which would have obviously knocked out the Co2)

Picked up sulphur too often so ditched the metabisuphite (never did use it in the mash) and eventually ditched the hot side centrifuge because of time and energy. Ended up just using the BtB in the mash because it was expensive and every penny counts when you are trying to run a business with a razor thin margin.

Just with BtB in the mash I could get a 4 month shelf life (in cans, longer in kegs) which was about what was needed so jumping through extra hoops, spending more time, energy and money could have squeezed more months out of the beers but it wouldn't have been worth it.

So, here we are again saying the same old thing - it depends on your  beer and what you are trying to accomplish. I don't use any gallotannin in my homebrew. So there's that. And if kept cold it has a really long shelf life. Not even sure how long - but long enough that it's usually still fresh when the keg is empty.

[ynotbrusum]

I use BTB in my strike water, but maybe I should add it to the mash - my thought was having it in the water as it is introduced to the grist was better....  I ferment under pressure and use closed transfer with a floating dip tube in the fermenter (Tilt hydrometer tells me when it has stopped dropping gravity).  No early transfer spunding is necessary, as I purge my kegs with CO 2 from early onset active fermentation filling the keg with sanitizer first and pushing it out with the CO2 from the fermentation, then use a spunding valve to avoid over carbonating.  The carbonated beer conditions in the keg. I get really good shelf life, but maybe it could be improved...

[dmtaylor]

Not that anyone cares, but... you guys lost me... and, it appears, the OP as well.  But by all means, carry on.   

[majorvices]

I use BTB in my strike water, but maybe I should add it to the mash - my thought was having it in the water as it is introduced to the grist was better.... 

It's best to add it to strike water just before dough in that just isn't practical on a 30 bbl HLT.

[BrewBama]

The Low O2 guys (I believe) have taken the approach to reduce/eliminate dissolved O2 in the mash thru use of sulfur based compounds, mash caps, etc.

Instead of focusing on reducing/elimination of O2, (which is kinda hard to do since it surrounds us), I think time is better spent focusing on the reaction.

Metal chelators like Brewtan B are fine but it's better to reduce them by using RO and changing your system to all stainless.

Essentially eliminating O2 in the mash actually isn't difficult. De-aerating the mash water, using an active scavenger like metabisulfite and mashcaps are quite effective as witnessed by in process DO meters that myself and a lot of other low oxygen guys have installed in our systems. I will see 0.00ppm O2 in the strike water at the underlet with a slight rise to 0.06ppm from oxygen dissolved into the grain itself but the meta will usually bring that right back to 0.00ppm within minutes and this will hold right the way through the mash and into the boil.

Low oxygen on the hot side is just one of those things that seems impossible until you do it and learn the tricks.

I have all stainless and start with distilled water in my mash process. ...but I don’t believe the material used to construct the system or lack of minerals in the brewing liquor addresses the oxidation reaction happening in the mash. IOW, the reaction still happens even in a stainless mash tun.

The change in temperature affects the amount of gas that a liquid can hold (i.e., the solubility of a gas in a liquid). Solubility decreases as temperature increases.

As I understand it, asuming normal atmospheric pressure and composition, water at 0˚C can hold a maximum of ~15ppm DO, while water at 50˚C can only hold ~5ppm. Once the water reaches 100˚C, solubility is zero.

Therefore, if you've brought water even close to a boil, you've removed virtually all the DO.  I heat my brewing liquor to ~165*F (73*C) and mash at ~152*F (66*C) so I am mashing in at, and maintaining < 5 ppm DO. (I don’t measure DO.)

I am looking into approaching the reaction problem from a different angle. I am looking into targeting the reaction by binding the elements that cause it vs addressing the O2 — which at 5 ppm is not bad given Joe’s response (below).

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[BrewBama]

Here’s the note I received from Joe this AM:

Dear Dwain,
You are exactly right!  The divalent ions such as Cu or Fe+2 interact with free oxygen in the system and via Fenton’s Reaction processes generate free radicals which cascade to oxidize the system.

Reduction or removal of these ions reduce the incidence of these reactions regardless of the level of oxygen present.

Remember, though, that not all ions are removed, which is OK because some are important for proper yeast functionality.  So a combination of oxygen reduction and ion removal is the best case scenario.  Tannic acid is not so much an oxygen scavenger as it is an ion remover, so if there is oxygen present it will not have as much of an effect.  This has worked well in systems where there is an inherent high level of DO due to equipment used.

Using Tannic acid as a mash water treatment helps remove the divalent ions right from the start of the mash and reduces the free radical cascade right from the start.

BTW – we were close to your location a few days ago when we were returning from a family vacation in Gulf Shores. Weather was just starting to get colder then.

Cheers!
Joe

******* break ********

I asked him a follow-up: understanding a combination of oxygen reduction and ion removal is the best case scenario, is <5 ppm low enough?  He said:

No problems Dwain!

5ppm is certainly quite low.

I usually preboil my water and cool it before adding Brewtan.  Not sure the final O2 ppm, but it should be quite low, as you suggest!

Cheers!
Joe

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[Bilsch]

Here’s the note I received from Joe this AM:

Dear Dwain,
You are exactly right!  The divalent ions such as Cu or Fe+2 interact with free oxygen in the system and via Fenton’s Reaction processes generate free radicals which cascade to oxidize the system.

Reduction or removal of these ions reduce the incidence of these reactions regardless of the level of oxygen present.

Remember, though, that not all ions are removed, which is OK because some are important for proper yeast functionality.  So a combination of oxygen reduction and ion removal is the best case scenario.  Tannic acid is not so much an oxygen scavenger as it is an ion remover, so if there is oxygen present it will not have as much of an effect.  This has worked well in systems where there is an inherent high level of DO due to equipment used.

Using Tannic acid as a mash water treatment helps remove the divalent ions right from the start of the mash and reduces the free radical cascade right from the start.

BTW – we were close to your location a few days ago when we were returning from a family vacation in Gulf Shores. Weather was just starting to get colder then.

Cheers!
Joe

******* break ********

I asked him a follow-up: understanding a combination of oxygen reduction and ion removal is the best case scenario, is <5 ppm low enough?  He said:

No problems Dwain!

5ppm is certainly quite low.

I usually preboil my water and cool it before adding Brewtan.  Not sure the final O2 ppm, but it should be quite low, as you suggest!

Cheers!
Joe

The only problem is that there are other pathways for oxidation in the mash then metal catalyzed via the Fenton reaction. You are so close with 5ppm, why not just continue to boiling temperatures and cool back to strike temperature?

[BrewBama]

I tried that. I quit because it was a PITA. I boiled, cooled, cooled too much, had to heat it back up to hit strike temp... screw it.

Now, I just set my Chef’s Alarm and when I hit my strike temp, I quietly drain off my sparge liquor into a HLT, start the pump to underlet the mash. Basta.

Close enough.


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[denny]

I tried that. I quit because it was a PITA. I boiled, cooled, cooled too much, had to heat it back up to hit strike temp... screw it.

Now, I just set my Chef’s Alarm and when I hit my strike temp, I quietly drain off my sparge liquor into a HLT, start the pump to underlet the mash. Basta.

Close enough.


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Exactly!  We all have our own goals for brewing and each of us decides what's worth it and what's not.

[HopDen]

I certainly don't want to diminish anyones process and I am actually intrigued that "hobbyists" delve this deeply into the art and science of brewing. My intellect in brewing maybe has more to do with the creation side where I can create a beer with the subtle nuance of the ingredients, much like cooking. I want to stay inside the proverbial box as far as style but enjoy stepping outside of those confines to create something unique to that style wether it is using different hops, schedules, temps or the addition of adjuncts or aging in wood when aging in wood may not be true to said style. Its all a matter of preference and practice.

Cheers

[Bilsch]

Sometimes the roadblock is simply unreasonable fear of complexity of new processes, especially if going by dated information. As the years have gone by and greater numbers of people have begun brewing low oxygen, a wealth of new ideas, systems and understanding of the proccedures have amassed and been proven out. These days it's really not much more complicated nor expensive to go full low oxygen from hot side to cold.

[beersk]

I tried that. I quit because it was a PITA. I boiled, cooled, cooled too much, had to heat it back up to hit strike temp... screw it.

Now, I just set my Chef’s Alarm and when I hit my strike temp, I quietly drain off my sparge liquor into a HLT, start the pump to underlet the mash. Basta.

Close enough.


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The thing I started doing was to use the yeast oxygen scavenging method where you use about a tablespoon of Red Star bread yeast and a tablespoon of sugar in the mash water over night. You can do it quicker too, but that's just how I did it. So much easier than pre-boiling.

[ynotbrusum]

I tried that. I quit because it was a PITA. I boiled, cooled, cooled too much, had to heat it back up to hit strike temp... screw it.

Now, I just set my Chef’s Alarm and when I hit my strike temp, I quietly drain off my sparge liquor into a HLT, start the pump to underlet the mash. Basta.

Close enough.


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The thing I started doing was to use the yeast oxygen scavenging method where you use about a tablespoon of Red Star bread yeast and a tablespoon of sugar in the mash water over night. You can do it quicker too, but that's just how I did it. So much easier than pre-boiling.

How much oxygen uptake occurs with the yeasted water sitting with headspace overnight after it is de-oxygenated?  I don't have a DO meter, but I have always wondered about that and how much oxygen is reintroduced into the strike water after boiling, then chilling, then  removing the wort chiller (some splashing involved).  Then, also, how much O2 is introduced in the removal of a grain bag/basket from an all in one kettle?

Since I didn't know the amount, I just went away from LO pre-boil and really don't notice a difference.  But I was hard core for a few years.  I am still hard core LO on the cold side, which I think helps.

[Richard]

I tried that. I quit because it was a PITA. I boiled, cooled, cooled too much, had to heat it back up to hit strike temp... screw it.

Now, I just set my Chef’s Alarm and when I hit my strike temp, I quietly drain off my sparge liquor into a HLT, start the pump to underlet the mash. Basta.

Close enough.


Sent from my iPad using Tapatalk

The thing I started doing was to use the yeast oxygen scavenging method where you use about a tablespoon of Red Star bread yeast and a tablespoon of sugar in the mash water over night. You can do it quicker too, but that's just how I did it. So much easier than pre-boiling.

How much oxygen uptake occurs with the yeasted water sitting with headspace overnight after it is de-oxygenated?  I don't have a DO meter, but I have always wondered about that and how much oxygen is reintroduced into the strike water after boiling, then chilling, then  removing the wort chiller (some splashing involved).  Then, also, how much O2 is introduced in the removal of a grain bag/basket from an all in one kettle?

Since I didn't know the amount, I just went away from LO pre-boil and really don't notice a difference.  But I was hard core for a few years.  I am still hard core LO on the cold side, which I think helps.

The yeast deoxygenation technique appears to act quite quickly and keep the DO level low for many hours:
https://www.themodernbrewhouse.com/deoxygenation-revisited/

The first few times I did this I started it the night before but now I heat the water to about 90 F, put the sugar and yeast in, give it 20-30 minutes and then continue to heat to strike temperature. It is very easy and avoids the troubles that BrewBama notes with pre-boiling and cooling.