Discussion on malty German beers

[Bilsch]

Speak for yourself please. I've never done injection as I find the idea of quick carbonating a beer that will then sit in maturation/lagering for weeks to be just a pointless gimmick, adding complexity and increasing the risk of infection through the use of unsanitary carbonation stones.
I've always carbed just fine by attaching my CO2 tank to the gas-in port, setting the right pressure and then letting the CO2 diffuse into the beer until equilibrium is reached. No wasted CO2, minimal O2 pickup according to Henry's law.

BTW I tried to start a discussion on this in the LODO section but it got almost completely ignored. Guess a discussion on the best way to force carbonate while minimizing O2 pickup didn't really fit your agenda? It must necessarily be "Spund or die!", right?

Maybe you didn't read through, or understand the paper from Hach so let me clarify the terms they use.

For the purposes relating to oxidative damage to beer:
Injection means.. that all the CO2 you put into the keg, including any O2 contaminant, will stay in there. Regardless of the shape of the nozzle it flows through to get in the keg.
Sparging means.. you will retain only some of the CO2 you put in the keg, in contact with the beer, and the rest will flow overboard through a calibrated leak thus washing out most of the O2 impurity as it goes. This 'washing' only works when there is a flow of gas, both in and out.

Therefore the way you describe attaching your CO2 tank to the gas in port is still considered injection with regards to oxidation and your keg/gas connection gives you no magic advantage over gas laws you speak of.
As the Hach paper states, and most large breweries know: "the purity of CO2 must be very high (99.99% or better) when using injection, or you will at the same time significantly increase your dissolved oxygen levels."

The science of all this is well known and no amount of obfuscation or quibbling over semantics will make that not so.

 

[Bilsch]

Careful my friend, if you go down that route you'll also start questioning homeopathy and crystal healing and magic water...
'cause we all know they work, right?

Most brewers who have tinkered with force carbonating fast by agitation under higher pressure vs doing it low and slow have observed these different methods will effect the quality and feel of the carbonation.
Therefore my question back to you is.. how does the CO2 in solution know if it came in fast or slow?

 

[doug293cz]

Most brewers who have tinkered with force carbonating fast by agitation under higher pressure vs doing it low and slow have observed these different methods will effect the quality and feel of the carbonation.
Therefore my question back to you is.. how does the CO2 in solution know if it came in fast or slow?

I believe that has to do with the equilibrium between dissolved CO2 and carbonic acid (haven't reviewed the details behind it in a while), but it's all rate related and a temporary non-equilibrium condition. People who try to carbonate in 15 minutes and immediately consume deserve what they get.

Brew on

 

[Vale71]

Most brewers who have tinkered with force carbonating fast by agitation under higher pressure vs doing it low and slow have observed these different methods will effect the quality and feel of the carbonation.
Therefore my question back to you is.. how does the CO2 in solution know if it came in fast or slow?

It doesn't, just as there is no "memory effect" in water (omeopathy) or "information transfer" (Granderwasser), they're all just a load of bullcrap.

There's a ton of people claiming that they can detect the difference between force carbonation and spunding, funnily though I don't see anybody doing a serious triangle test to prove that this is not just another urban legend. A condition for the test being meaningful is of course that the beer then will have to rest in maturation for an equal amount of time. Even a child knows that if you try and drink a carbonated drink shortly after shaking it vigorously you'll get a very different result than what you'll get if you handle it properly.

Until such a test is performed people "observing" differences in quality and feel of carbonation are "observing" diddly-squat and are just believing what they would like to be true.

 

[Vale71]

Injection means.. that all the CO2 you put into the keg, including any O2 contaminant, will stay in there. Regardless of the shape of the nozzle it flows through to get in the keg.
Sparging means.. you will retain only some of the CO2 you put in the keg, in contact with the beer, and the rest will flow overboard through a calibrated leak thus washing out most of the O2 impurity as it goes. This 'washing' only works when there is a flow of gas, both in and out.

So you're saying that it doesn't matter if all the O2 is dissolved into the beer or if only a small percentage, as determined by Henry's law, actually gets into the beer while the rest stays in the headspace? Care to explain why you think that or are you just trying to obfuscate things?

I also fail to see how CO2 that is contaminated with O2 should be able to wash away the O2 contamination it has itself brought in?

 

[Bilsch]

My understanding and observation for the reason that carbonation from spunding is immediately soft and fine in comparison to force carbonating is that it takes time for the CO2 in solution to fully convert to carbonic. Over time the the forced carbonated keg will come to equilibrium and the carbonation chemistry will be similar.

The major difference between the two methods is that when yeast ferment under pressure they create more glycerine which is a foam positive constituent and thus improves the head appearance and duration dramatically.

I believe this is one reason that so many people have noted a great difference after their first spund they never saw in previous forced batches.

 

[Big Monk]

So you're saying that it doesn't matter if all the O2 is dissolved into the beer or if only a small percentage, as determined by Henry's law, actually gets into the beer while the rest stays in the headspace? Care to explain why you think that or are you just trying to obfuscate things?

I also fail to see how CO2 that is contaminated with O2 should be able to wash away the O2 contamination it has itself brought in?

Do you have headspace in your kegs? If so, why?

Most people work really hard to eliminate as much of the headspace in the keg as possible by modifying the dip tubes.

 

[Bilsch]

It doesn't, just as there is no "memory effect" in water (omeopathy) or "information transfer" (Granderwasser), they're all just a load of bullcrap.

There's a ton of people claiming that they can detect the difference between force carbonation and spunding, funnily though I don't see anybody doing a serious triangle test to prove that this is not just another urban legend. A condition for the test being meaningful is of course that the beer then will have to rest in maturation for an equal amount of time. Even a child knows that if you try and drink a carbonated drink shortly after shaking it vigorously you'll get a very different result than what you'll get if you handle it properly.

Until such a test is performed people "observing" differences in quality and feel of carbonation are "observing" diddly-squat and are just believing what they would like to be true.

To be clear.. I said nothing about silly pseudoscience like water memory so the only obfuscation in that regard is coming from you.

The trick of carbonation as eluded to by Doug293cz is that it takes time for it to happen. This quote from a member on another forum explains it nicely, "Injecting CO2 into an aqueous solution initially produces an aqueous CO' product (CO2 + H2O = CO2aq). It takes time for that aqueous CO2 to hydrate into its end form: carbonic acid (H2CO3)."
The reversal of this process, the evolution of CO2, also takes more or less time depending on which form the CO2 is in your beer. Thus it is possible to observe different quality and sizes of bubbles and they sometimes form differently. As for the quality of the foam in spunded beers.. please see my explanation in another post on the creation of the foam positive substance glycerine.

And again.. this is all settled and well understood science. Because you don't understand it, does not make it untrue.

 

[Bilsch]

So you're saying that it doesn't matter if all the O2 is dissolved into the beer or if only a small percentage, as determined by Henry's law, actually gets into the beer while the rest stays in the headspace? Care to explain why you think that or are you just trying to obfuscate things?

I also fail to see how CO2 that is contaminated with O2 should be able to wash away the O2 contamination it has itself brought in?

I'm sorry you do not understand the science behind sparging vs injection. The advantages and disadvantages are quite clearly explained. Also you keep throwing out Henry's law like it somehow supports your thesis but in fact quite the reverse is true. Possibly you did not even read the Hach paper, so let me save you the time and I'll post the most relevant sections here.

"First, let’s do a quick review of what happens when you inject CO2. When you inject gas (usually into a pipe,) you are forcing a given weight of gas into the liquid under pressure. All of the carbon dioxide, plus any trace oxygen and nitrogen, gets pushed into the beer and dissolves completely, allowing you to calculate the weight of gas used and extrapolate from there your various gas concentrations."

"On the other hand, when you sparge gas into a liquid the dissolved concentration of gas will be bound by Henry’s Law. Henry’s Law tells us that the amount of gas that will dissolve in a liquid will be proportional – at a constant temperature – to the partial pressure of gas in equilibrium with the liquid. This means that the gasses dissolved in your beer will never be more concentrated that the partial pressure of the gas you are using to sparge."

"The consequence is that, with any given CO2 concentration outcome desired, you will have significantly lower oxygen concentrations for sparged beer then for injected beer. For example, in injected beer the oxygen pickup from injecting one volume of 99.95% CO2 (at 0oC) into the beer when the oxygen concentration is 0.01% is 143 ppb. But a theoretical sparging of that same CO2 into the beer at atmospheric pressure would follow Henry’s Law, and your oxygen pickup would be about 7 ppb. In real brewing situations, however, most brewers use tank overpressure to help get sparged CO2 into solution, so you would probably be picking up about 2 times the above amount, or 14 ppb."

This stuff is based on high school level science concepts so it's not difficult to get a grasp on it if one reads up on it a bit, which I urge you to do more of before blindly posting about it being impossible.

P.S. There is another nice paper also from Hach on the same website titled: O2 Impurity in Carbon Dioxide: How Much is Too Much? which I think everyone who force carbonates would benefit from reading.

 

[bierhaus15]

And again.. this is all settled and well understood science. Because you don't understand it, does not make it untrue.

Since LOWDO process is all settled science, please provide evidence that force carbonation alone increases DO above 30 ppm through normal process, as your head honcho guy keeps pointing out. Surely there would be plenty of evidence to support this, with 6,000+ breweries in the US and the majority of them force carbonating.

According to Hach and their blog posts, the most 02 pickup you'll likely see using terrible C02 is 1.4 ppm. And a more realistic average is what, 20 ppb?

I am also still waiting to see evidence of a single German brewery that uses SMB, KMB, or ascorbic acid, or advocates its use.

And while spunding is arguably better for beer than force carbonation when done properly, it is not without issues, especially for home brewers. How do you know your level of S02, DMS, and acetaldehyde is appropriately low before you start the spund? Id rather have 20 ppb of 02 from force carbonating than unknowingly end up with above threshold levels of H2S, S02, ect, from spunding; especially when combined with antioxidant use.

 

[Big Monk]

I am also still waiting to see evidence of a single German brewery that uses SMB, KMB, or ascorbic acid, or advocates its use.

They don’t and no one ever said they did.

 

[Bilsch]

Ugh.. does anyone read anymore before posting?

Lets be clear, we were discussing injection vs sparging and the physics behind that. Therefore your assertion that I claimed that "LOWDO process is all settled science" is silly.

Secondly.. who is this head honcho you refer to? The only boss I ever had was my ex wife and that problem was solved a long time ago. These days I only speak for myself so if you want explanations of other people's statements, I kindly direct you to them.

According to Hach and their blog post, I will point you to the table provided in one of the posts I referred to:
Co2 Injected - O2 Impurity - O2 Impurity -O2 Impurity
----------- 0.001% - 0.005% - 0.02%
0.5 V/V - 7 ppb - 35 ppb - 142 ppb
1.0 V/V - 14 ppb - 71 ppb - 284 ppb
2.0 V/V - 28 ppb - 142 ppb - 567 ppb
I don't know where you got the 1.4ppb figure from but it is incorrect.

As has been explained on this and other forums ad nauseum, large German breweries do not have to use sulfites or other oxygen scavengers since they have the advantages of:
1) Having water de aeration equipment.
2) Being able to push water/beer around and blanket the grain mills etc with nitrogen.
3) Square cube law affords them protection with much smaller contact surface area of the mash with the atmosphere.
Sulfite oxygen scavengers are simply a hack so that home brewers with less sophisticated equipment can approximate what low oxygen breweries do. And while they worked quite effectively, I have since moved beyond sulfites by having built a fairly simple nitrogen purged system.

I can only speak for myself but I don't have a problem with S02, DMS, H2S etc because I only pitch an appropriately large and healthy amount of yeast and my ferments progress fast and without issue. It's not difficult to do if you follow a few common sense guidelines.

But I suspect you don't really want to know about any of this, since there has been availability and easy access to all the information and science behind low oxygen brewing for a couple years now, but in fact would prefer to argue that it is simply the machinations of some crazy brewing cult.

 

[Big Monk]

Ugh.. does anyone read anymore before posting?

Lets be clear, we were discussing injection vs sparging and the physics behind that. Therefore your assertion that I claimed that "LOWDO process is all settled science" is silly.

Secondly.. who is this head honcho you refer to? The only boss I ever had was my ex wife and that problem was solved a long time ago. These days I only speak for myself so if you want explanations of other people's statements, I kindly direct you to them.

According to Hach and their blog post, I will point you to the table provided in one of the posts I referred to:
Co2 Injected O2 Impurity O2 Impurity O2 Impurity
0.001% 0.005% 0.02%
0.5 V/V 7 ppb 35 ppb 142 ppb
1.0 V/V 14 ppb 71 ppb 284 ppb

2.0 V/V 28 ppb 142 ppb 567 ppb
I don't know where you got the 1.4ppb figure from but it is incorrect.

As has been explained on this and other forums ad nauseum, large German breweries do not have to use sulfites or other oxygen scavengers since they have the advantages of:
1) Having water de aeration equipment.
2) Being able to push water/beer around and blanket the grain mills etc with nitrogen.
3) Square cube law affords them protection with much smaller contact surface area of the mash with the atmosphere.
Sulfite oxygen scavengers are simply a hack so that home brewers with less sophisticated equipment can approximate what low oxygen breweries do. And while they worked quite effectively, I have since moved beyond sulfites by having built a fairly simple nitrogen purged system.

I can only speak for myself but I don't have a problem with S02, DMS, H2S etc because I only pitch an appropriately large and healthy amount of yeast and my ferments progress fast and without issue. It's not difficult to do if you follow a few common sense guidelines.

But I suspect you don't really want to know about any of this, since there has been availability and easy access to all the information and science behind low oxygen brewing for a couple years now, but in fact would prefer to argue that it is simply the machinations of some crazy brewing cult.

I wish I could double like this post. Well said Bilsch.

 

[brewbama]

I don't know where you got the 1.4ppb figure from but it is incorrect.

It’s in the paper you cited but it’s 14 not 1.4:

“In real brewing situations, however, most brewers use tank overpressure to help get sparged CO2 into solution, so you would probably be picking up about 2 times the above amount, or 14 ppb.”

 

[TheMadKing]

I don't know about you guys, but I'm on my third delicious homebrew.

I'm done with this whole debate. I'm just going to keep brewing and trying new things.

So far, Lodo techniques have not made my beers worse, nor have they become significantly better. Sauergut is cool and I'm planning to use it in most of my future German styles.

I will also try spunding since I already built a spunding valve and was planning to, before I was accused of heresy.

Good luck spreading your gospel, but maybe show a little humility and you won't meet so much resistance. Even the smartest teachers should be open to learning from students. And even the smartest students should always realize that they don't know everything.

Keep brewing everyone. Don't be arrogant. Don't be a dick. Don't take any of it too seriously. It's only beer, and none of us are terribly important in the big picture.

 

[Bilsch]

It’s in the paper you cited but it’s 14 not 1.4:

Ah.. ok, thank you.
Yes and that 14ppb would only be possible if one only carbonated to 1 volume and used CO2 with a purity of 99.99% or better which isn't beverage grade. I think we could all agree this is cherry picking your data.

 

[Big Monk]

I don't know about you guys, but I'm on my third delicious homebrew.

I'm done with this whole debate. I'm just going to keep brewing and trying new things.

So far, Lodo techniques have not made my beers worse, nor have they become significantly better. Sauergut is cool and I'm planning to use it in most of my future German styles.

I will also try spunding since I already built a spunding valve and was planning to, before I was accused of heresy.

Good luck spreading your gospel, but maybe show a little humility and you won't meet so much resistance. Even the smartest teachers should be open to learning from students. And even the smartest students should always realize that they don't know everything.

Keep brewing everyone. Don't be arrogant. Don't be a dick. Don't take any of it too seriously. It's only beer, and none of us are terribly important in the big picture.

Many of us are in a place where constantly having to correct misinterpretations, defend against ad hominems, and just plain repeat the same things over and over again is so tiresome and depressing.

Everyone needs to do what works for them. No one disagrees with that. We just get frustrated at people who come in slingin mud and are either misrepresenting something that was previously said or flat out don’t understand the topic at all.

Do you and enjoy yourself. That’s my motto.

 

[bierhaus15]

1.4 ppm (notice the m) was the highest DO increase one could theoretically see with bad C02 and typical process. Far below the 2-3 ppm as touted as the normal amount I keep seeing referenced by your members. But Hach says the actual is far lower and that is consistent with what I have seen professionally. Even beverage grade C02 from bulk welding supply don't result in DO jumps that high.

"Most brewers specify a minimum CO2 purity of 99.990%. This equates to an oxygen impurity of about 0.002%. If one V/V of CO2 with this oxygen content were injected into beer, the resulting increase to the beer O2 would be about 28 ppb."

Sorry all you LOWDO guys feel threatened, but you don't get to make blanket statements without someone taking offense. As for cherry picking data, have you read the "Bavarian Helles" manifesto?! Brewing science has advanced beyond Narziss and 50 year old data. I won't even bother with the antioxidant bit.

Anyways, I can see these arguments aren't helping anything. Do whatever you want, that is the beauty of home brewing...

 

[Bilsch]

Anyways, I can see these arguments aren't helping anything. Do whatever you want, that is the beauty of home brewing...

Very cool, there is hope for progress since it seems in this we at least have something to agree on.

 

[brewbama]

1.4 ppm (notice the m)...

I stand corrected.

 

[doug293cz]

So you're saying that it doesn't matter if all the O2 is dissolved into the beer or if only a small percentage, as determined by Henry's law, actually gets into the beer while the rest stays in the headspace? Care to explain why you think that or are you just trying to obfuscate things?

I also fail to see how CO2 that is contaminated with O2 should be able to wash away the O2 contamination it has itself brought in?

I'm sorry you do not understand the science behind sparging vs injection. The advantages and disadvantages are quite clearly explained. Also you keep throwing out Henry's law like it somehow supports your thesis but in fact quite the reverse is true. Possibly you did not even read the Hach paper, so let me save you the time and I'll post the most relevant sections here.

"First, let’s do a quick review of what happens when you inject CO2. When you inject gas (usually into a pipe,) you are forcing a given weight of gas into the liquid under pressure. All of the carbon dioxide, plus any trace oxygen and nitrogen, gets pushed into the beer and dissolves completely, allowing you to calculate the weight of gas used and extrapolate from there your various gas concentrations."

"On the other hand, when you sparge gas into a liquid the dissolved concentration of gas will be bound by Henry’s Law. Henry’s Law tells us that the amount of gas that will dissolve in a liquid will be proportional – at a constant temperature – to the partial pressure of gas in equilibrium with the liquid. This means that the gasses dissolved in your beer will never be more concentrated that the partial pressure of the gas you are using to sparge."

"The consequence is that, with any given CO2 concentration outcome desired, you will have significantly lower oxygen concentrations for sparged beer then for injected beer. For example, in injected beer the oxygen pickup from injecting one volume of 99.95% CO2 (at 0oC) into the beer when the oxygen concentration is 0.01% is 143 ppb. But a theoretical sparging of that same CO2 into the beer at atmospheric pressure would follow Henry’s Law, and your oxygen pickup would be about 7 ppb. In real brewing situations, however, most brewers use tank overpressure to help get sparged CO2 into solution, so you would probably be picking up about 2 times the above amount, or 14 ppb."

This stuff is based on high school level science concepts so it's not difficult to get a grasp on it if one reads up on it a bit, which I urge you to do more of before blindly posting about it being impossible.

P.S. There is another nice paper also from Hach on the same website titled: O2 Impurity in Carbon Dioxide: How Much is Too Much? which I think everyone who force carbonates would benefit from reading.

The problem with the Hach paper is that it does a terrible job of explaining what is going on which makes sparging different from injection. I'll try to explain things a little more clearly (I may or may not succeed.)

Let's say you have a keg containing 19 L of beer and 1.3 L of headspace (typical values for a 5 gal corny) and you want to carb it to 2.5 volumes at 5˚C (41˚F). The beer starts with 0.8 volumes of carb at the end of fermentation, so we need to add enough CO2 to the beer to raise the carb level by 1.7, and also fill the headspace with CO2 at a pressure of 12.7 psig (27.4 psi partial pressure.) One volume of CO2 is 1.977 g/L, so the beer needs 19 L * 1.7 * 1.977 g/L = 64 g of CO2 added. The headspace needs to have 1.3 L * 1.977 g/L * (27.4 psi / 14.7 psi) * (273.15˚K / 278.15˚K) = 4.7 g of CO2 to be in equilibrium. So we need to add 68.7 g of CO2 to the keg. If the CO2 we add contains 0.01% O2, then we also add 68.7 g * 0.01% / 100% = 0.00687 g of O2. That O2 will be mostly in the headspace since little will be absorbed in the beer.

The preceding is the case for injection carbonation where all the O2 that was added along with the CO2 stays in the headspace.

Now if we bubble CO2 from the bottom of the beer, some will be absorbed into the beer and some will escape to the headspace. Most of the O2 that comes in with the CO2 will not dissolve in the beer, but escape to the headspace. If we put a controlled leak in the headspace so that some of the gas that makes it to the headspace escapes into the atmosphere (while maintaining adequate pressure in the headspace) then some of the O2 in the headspace will also escape. If we didn't have the controlled leak, then all of the O2 that came in with the CO2 would remain in the beer or headspace, just like injection. If we allow enough headspace gas to escape, we can get the headspace O2 concentration down to the same as the incoming CO2. This is equivalent to purging the headspace of O2 after kegging by doing multiple pressurize and vent cycles. You also waste a considerable amount of CO2 by letting it escape. In this case the minimum amount of O2 in the headspace would be 4.7 g * 0.01% / 100% = 0.00047 g. This is more than 10 times less than the case for injection. The less O2 in the headspace, the lower the O2 partial pressure, and the less O2 gets absorbed into the beer.

Brew on

 

[schematix]

Because you don't understand it, does not make it untrue.

This is HBT, you know.

The problem with the Hach paper is that it does a terrible job of explaining what is going on which makes sparging different from injection. I'll try to explain things a little more clearly (I may or may not succeed.)

Another fascinating explanation. Thank you sir.

 

[Vale71]

I'm sorry you do not understand the science behind sparging vs injection. The advantages and disadvantages are quite clearly explained. Also you keep throwing out Henry's law like it somehow supports your thesis but in fact quite the reverse is true. Possibly you did not even read the Hach paper, so let me save you the time and I'll post the most relevant sections here.

"First, let’s do a quick review of what happens when you inject CO2. When you inject gas (usually into a pipe,) you are forcing a given weight of gas into the liquid under pressure. All of the carbon dioxide, plus any trace oxygen and nitrogen, gets pushed into the beer and dissolves completely, allowing you to calculate the weight of gas used and extrapolate from there your various gas concentrations."

"On the other hand, when you sparge gas into a liquid the dissolved concentration of gas will be bound by Henry’s Law. Henry’s Law tells us that the amount of gas that will dissolve in a liquid will be proportional – at a constant temperature – to the partial pressure of gas in equilibrium with the liquid. This means that the gasses dissolved in your beer will never be more concentrated that the partial pressure of the gas you are using to sparge."

"The consequence is that, with any given CO2 concentration outcome desired, you will have significantly lower oxygen concentrations for sparged beer then for injected beer. For example, in injected beer the oxygen pickup from injecting one volume of 99.95% CO2 (at 0oC) into the beer when the oxygen concentration is 0.01% is 143 ppb. But a theoretical sparging of that same CO2 into the beer at atmospheric pressure would follow Henry’s Law, and your oxygen pickup would be about 7 ppb. In real brewing situations, however, most brewers use tank overpressure to help get sparged CO2 into solution, so you would probably be picking up about 2 times the above amount, or 14 ppb."

This stuff is based on high school level science concepts so it's not difficult to get a grasp on it if one reads up on it a bit, which I urge you to do more of before blindly posting about it being impossible.

P.S. There is another nice paper also from Hach on the same website titled: O2 Impurity in Carbon Dioxide: How Much is Too Much? which I think everyone who force carbonates would benefit from reading.

I've taken the liberty of highlighting the parts that confirm my statement that pumping CO2 into the headspace with the same purity grade CO2 will result in much lower O2 levels than what you'd get if you were to carbonate through injection with the same grade CO2. In this case you'll end up at 14 ppb instead of 143 or about 1/10th. If you still don't understand the difference then I'm sorry but you're the one who obviously doesn't understand the underlying physical principles. The huge difference is due to the fact that O2's solubility is approximately 3.7% that of CO2, so a lot more O2 has to stay in the headspace for very little O2 to actually get into the beer. Yes, there is some O2 enrichment of the headspace if you don't vent it so that the O2 concentration in the headspace will increase and Hach estimates this will lead to a doubling of the concentration of dissolved oxygen, but still we're talking 14 ppb against ten times that! If that isn't a huge difference than I don't know what is.
Anyway, I'm done with this discussion too. I'm really tired of converts trying to hand me pamphplets that said converts don't even fully understand themselves and then being insulted if I try and point out the faults in their interpretation. If I were into that I'd just go to the local chapter of Jehova's Witnesses, but I'm not, so...

 

[Big Monk]

I won't even bother with the antioxidant bit.

Like I said, this is a bit of a sticking point for some people. It's simply a hack designed to replicate the safety margin (WRT DO pickup) that large breweries get from gassing grist and the Square Cube Law (among other techniques).

I just want to be clear: no one that I know of has ever claimed that large commercial breweries use sulfites on the hot side.

 

[brewbama]

... O2 will be mostly in the headspace since little will be absorbed in the beer.

I’ve always tried to reconcile the statement (below) with brewing and the requirement to use antioxidants to lower dissolved O2 in beer.

*For water in equilibrium with the atmosphere, the concentration is governed by Henry's Law, and KH for O2 is 769.23. We can calculate the concentration of O2(aq) to be 0.00027 M.

When water is heated to strike temp and and then the wort to mash temps the O2 concentration is reduced. And once boiled it is reduced even more than in the mash. In my mind, this eliminates the ‘hot side’ as a source of dissolved O2. Therefore, antioxidants should not be required here.

The problem arises when the beer is cooled to yeast pitching temps. The surface layer of the wort can begin to pick up O2 molecules at a fairly slow rate. This rate could be increased if the wort is transferred with more turbulence. Once yeast is pitched, they consume the dissolved oxygen as a function of their natural processes. In fact, more O2 is said to be required for their consumption so O2 is added for this purpose. In my mind, this eliminates dissolved O2 in beer up to the point of packaging because the yeast consume the O2. Therefore, antioxidants should not be required up to this point.

Edit: I should add packaging: To purge a keg of oxygen, many homebrewers remove the oxygen from a keg by filling it completely with *liquid* then remove the *liquid* with ‘pure’ CO2. Finally we replace the CO2 with beer via “closed transfer”. Very little if any O2 pickup in this packaging process.

While spunding is economically more advantageous (yeast produce CO2 for carbonation vs carbonation from a bottle), given that O2 is 25 X +/- less soluble than CO2 in 25C water at atmospheric pressure (somewhat different in a keg of beer), if the bottled CO2 is ‘pure’ enough,the result of set it and forget it force carbonation should be very little O2 in concentration of the beer. And the O2 that does enter the beer could possibly be limited to the surface layer.

*Ref http://butane.chem.uiuc.edu/pshapley/GenChem1/L23/web-L23.pdf

 

[Big Monk]

I don't want to be contentious. I just want to present a few things as counterpoint:

When water is heated to strike temp and and then the wort to mash temps the O2 concentration is reduced.

Reduced, yes, but not eliminated. Solubility at mash temps is still ~4-5 ppm. The crux of the issue has always been that the flavors we associate with LO, particularly malt flavors, i.e. fresh lingering grain, are tied to one or more of the low weight malt polyphenol compounds (PPO is a likely candidate although there are others) which themselves have antioxidant properties. That means they will be the first in line to oxidize at the DO levels present at mash temps.

That's why it ends up being so important to us not to mash in to oxygen saturated strike water.

And once boiled it is reduced even more than in the mash.

This is true. That's why we boil the strike water prior.

In my mind, this eliminates the ‘hot side’ as a source of dissolved O2. Therefore, antioxidants should not be required here.

If we consider that strike water will have ~4-5 ppm DO if untreated, then I agree with you. Someone not performing a LO mash will have no need for antioxidants.

On the other hand, if I am performing a LO mash, even if I pre-boil the water, I still need a mash antioxidant or a purging system to ensure that mashing in doesn't dramatically increase the DO content and to mitigate the ingress from atmospheric oxygen, i.e. an antioxidant provides a safety margin during the duration of the mash. Depending on how you mash in, you can introduce between ~1-3 ppm DO, and intrusion from atmospheric oxygen can be upwards of 1 ppm/hr.

As far as kegging is concerned, I try to "stay in my lane", as I am a bottler and always will be. I just don't have the knowledge, outside of what i can research and observe from my collaborators, that is required to make compelling arguments for or against those packaging methods.

The big takeaway in my opinion is that for someone performing the traditional homebrew mash (how does NorDO strike you?!) your assessments are accurate.

For the LO mash, however, the initial strike water DO content is paramount and an antioxidant (or grist purging) plus the use of a physical barrier such as a mash cap (or mash "headspace" purge) is important to keep DO levels low prior to pitching yeast.


Just for posterity sake, I should point out that as people progress with the LO mash methods, they tend to significantly decrease (or in the case of those who use purging eliminate) the use of antioxidants. This is due to pre-treating the strike water, underletting, mixing grain and water gently, and capping the mash. Ultimately we arent talking about large amounts of antioxidants in the mash.

 

[brewbama]

I imagine bottling would present more O2 pickup problems that would have to be solved. A keg solves a lot of problems.

Underletting the mash is also considered a safety measure in my brewery. Lifting ~50 lbs of kettle filled with very hot water chest high was a problem too simple to eliminate by adding a pump. I slowly transfer at ~.7 gpm and as a result the added benefit of no dough balls is very welcome.

 

[bierhaus15]

Like I said, this is a bit of a sticking point for some people. It's simply a hack designed to replicate the safety margin (WRT DO pickup) that large breweries get from gassing grist and the Square Cube Law (among other techniques).

I just want to be clear: no one that I know of has ever claimed that large commercial breweries use sulfites on the hot side.

Ok...one last go at it and I'll shut up.

Surely you see the irony here. First, by large breweries you mean German breweries, many of which do not use nitrogen mashing or DA mash water and yet still have that "it" character so fetishized by the LOWDO community. Interestingly, no one can seem to provide real evidence of what exactly "it" is. Secondly, on principle alone, no German brewer I have ever met would agree that "German" beer can be made via the use of antioxidants. They even have a beer law that says as much. I think you'd have a better chance of getting a French winemaker to agree that Bordeaux can be made using a portion of Concorde grape juice. If you know of a German brewery using antioxidants on the cold side, I'm all ears.

Sarcasm aside, there are also some very good reasons to not use antioxidants in the mash. Principal among the being that S02 from S/KMB binds to aldehydes in the mash, forming acetaldehyde bisulfate adducts, along with bound trans-2-nonenal and other detrimental compounds. This is significant as bisulfate adducts cannot be reduced by yeast during fermentation. That means that any S02 and similar off flavors are retained in the beer and cannot be scrubbed out via C02, fermentation, ect. The process of consuming 02 via sulfites in the mash also interacts with polyphenols that later react with metal ions in the boil and oxidizes. But you don't have any metal in your wort you say? Malt provides it. Might want to use BTB to mitigate this, but alas, we know that BTB cannot chelate ALL malt bound metal ions in the mash, as that is mostly accomplished through boil trub formation and fermentation. And most unfortunate, low beer pH during beer extended storage disassociates bisulfate bound aldehydes back into the beer. Interestingly, wort lipids in kettle trub help mitigate these effects, but LOWDO practice to ensure low lipid levels. Antioxidants also reduce beer foam stability, but that's pretty minor in the big picture. Lastly, there is also some recent evidence from Leuven that shows how the reducing power of antioxidants itself can do more harm to beer flavor than is gained via the 02 reduction.

This obsessive anti-mash 02 overlooks some of the biggest and more detrimental issues that arise with antioxidant usage. I would rather see 50 ppm of 02 in my mash and maybe see some minor oxidation flavors in my beer 2 months after brewing, than 100% of the time end up with detrimental compounds in my beer from antioxidant use. I'd rather see people focusing on things that have the biggest impact, like process and fermentation. Having worked in a large brewery where one system used LOWDO process (not that it was ever called as such) and the other did not, I can say the principal difference between the two was noticed in pasteurized bottles after a month. All said, LOWDO process does offer real benefits and if you have the $$$ to explore them, great. My issue really lies with the proselytizing and mash antioxidant use. Cheers.

 

[Big Monk]

I imagine bottling would present more O2 pickup problems that would have to be solved. A keg solves a lot of problems.

Right. When I make LO batch (keep in mind that when time is restricted I still make batches using traditional processes) I typically bottle with remaining extract to ensure active fermentation is still underway, even in the bottles. That presents other issues to deal with but so far so good.

One of the popular misconceptions about LOB is that you need to have a system like The Beerery to do it. That's just not the case. It's something that I think gets lost in the noise sometimes.

We have people with very simple systems making some of the best beer they ever have, subjectively speaking of course. Most are quickly able to get their antioxidant dose down very low, or in the case of nitrogen purging, eliminate it altogether.

This typically doesn't cost anyone more than a mash cap and some metabisulfite. Most of the tweaks are process based.

 

[Big Monk]

My issue really lies with the proselytizing and mash antioxidant use.

To be totally fair here, we are talking about extremely small doses of mash antioxidants. We've amended the starting values continuously to reflect current best practices.

The person coming right "off the street" is advised to implement things like gentle stirring, underletting, mash cap, etc. and then use 25 ppm or less until they get their system dialed in. It's not uncommon for people just getting into it to start at 20 ppm and drop to around 10 ppm. For those gassing their grist, that number drops to 0 ppm.

As far as ill effects of using NaS2O5 or KS2O5, the combined effects of BTB use in the Mash and Boil, elimination of copper, and the suggested use of RO/DI water, as well as proper oxygenation at yeast pitching time to use up any remaining sulfites, seems to keep most peoples finished product free of the issues you describe.

If you know of a German brewery using antioxidants on the cold side, I'm all ears.

I don't know of any and wouldn't expect them to. As far as I know, we've never recommended anyone do that either. Closed transfers, spunding, proper keg purging, and yeast derived sulfites are the keys on the cold side.

Sarcasm aside, there are also some very good reasons to not use antioxidants in the mash. Principal among the being that S02 from S/KMB binds to aldehydes in the mash, forming acetaldehyde bisulfate adducts, along with bound trans-2-nonenal and other detrimental compounds. This is significant as bisulfate adducts cannot be reduced by yeast during fermentation. That means that any S02 and similar off flavors are retained in the beer and cannot be scrubbed out via C02, fermentation, ect. The process of consuming 02 via sulfites in the mash also interacts with polyphenols that later react with metal ions in the boil and oxidizes. But you don't have any metal in your wort you say? Malt provides it. Might want to use BTB to mitigate this, but alas, we know that BTB cannot chelate ALL malt bound metal ions in the mash, as that is mostly accomplished through boil trub formation and fermentation. And most unfortunate, low beer pH during beer extended storage disassociates bisulfate bound aldehydes back into the beer. Interestingly, wort lipids in kettle trub help mitigate these effects, but LOWDO practice to ensure low lipid levels. Antioxidants also reduce beer foam stability, but that's pretty minor in the big picture. Lastly, there is also some recent evidence from Leuven that shows how the reducing power of antioxidants itself can do more harm to beer flavor than is gained via the 02 reduction.

This is quite a bit to unpack, although I can't say I have ever experienced any of this, even during the times when I used 100 ppm in the mash. Those days are long gone and as stated above, the recommended doses are considerably lower.

With that said, we are always open to new information.