Welcome to another episode of Respecting the Beer. My name is Gary Arndt. And with me again is Bobby Fleshman and Allison McCoy. We've talked about. Sight, how a beer looks, we've talked about smell, it's aroma. Today, we're going to talk just specifically about one aspect of, of how something looks, and that is bubbles and carbonation, a really important part of beer. We've talked to in an earlier episode, but the reinheitsgebot and the rules about how beer could only have three ingredients. It could have yeast, malt, and hops now, I guess. But. There really is another ingredient and that ingredient is dissolved carbon dioxide in most cases, where does the carbon dioxide come from? How important is it in the process of making a beer? Because we're going to get into it because not all beers have the same level of carbonation, right?

Fermentation did really cut to the chase. The core of fermentation is to turn sugar. into one part alcohol, ethanol, and one part carbon dioxide. And you'll get one molecule of each at the end of the process. There's a million other steps along the way, but that is the core of what's happening. And in order to do that, you have to have yeast and you have to have the right food source, a sugar they can consume. And that's the job of the brewer, the maltster.

Is the implication of that, that a higher alcohol beer is going to have more carbonation.

If you, so that's a great question. It will produce more. we can't because of the laws of, of Henry's law, we can't possibly imagine a way to contain it. We could maybe from a engineering standpoint, you would be talking thousands of pounds of pressure at the end of the day. but from a, from a yeast standpoint, they would obviously not enjoy that too much.

I have to interject. I'm so sorry. So you can't just say Henry's Law and assume that everyone knows what that is.

And that's why I opened the door here.

Anyway, so you've all been there. You've shaken up a bottle of soda and then you open up the soda and guess what happens? It goes everywhere. That's Henry's Law. So the more CO, so CO2 does not want to be in the water. the water. And so it's going to escape, and it's a gas, so it's going to escape out of the liquid. And so Henry's Law tells you how much of that CO2 you can get to actually stay in the liquid. And when you open up that shaken soda, Henry's Law is like, nope! Won't stay in. So out onto you, it comes.

Right. So we live and die by Henry's law and brewing, whether we know it or not. And it, we can use it when we're using gas blends and nitrogen and CO2 and so on. But yeah, you were saying, does the higher alcohol beer end up with higher levels of CO2? No, we tend to, to only leave in it what we need for balance. Most beers are. coming in at, with a, with a range, but, but they're, they're all in the sort of the same category. Alice is waving.

But so when you have the big fermenters and we've normally got the fermenters, this is the place where we're going to have the yeast eating the sugar, pooping out the CO2 and pooping out the alcohol. So we have a hose that goes down into a bucket and that bucket is continuously just bubbling and gurgling, and really we walk by and we're like, Oh, the yeast are eating and happy. But I'm guessing for the higher alcohol Beer is just more CO2 escapes and we just don't keep it in. So you're talking about final product CO2 in the beer. Whereas I think Gary's talking about just in the overall process, it should. So he's right. It should create more CO2.

And next step around here. One of our millions of projects is to reclaim it. So once we have it. We can clean it, make it pure, use it for what we call tank purging, line purging. The purpose there is that we want to make sure that our finished beer doesn't come into contact with oxygen. So we create inert environments.

Speaking of CO2 in the brewing industry CO2, so it was originally known as fixed air and I believe, Joseph Priestley back in the day, gosh, this was like 1800s or so. or maybe 1700s. He was an English chemist and he was playing around with it but it was called fixed air and they did all sorts of tricks with it. And the thing is, is that it sinks because it's more dense than so CO2 is more dense than the regular air, which is oxygen, nitrogen and argon combination. And so if you happen to be a home brewer and you are fermenting in a freezer, like a chest freezer, and I speak from personal experience, if you drop something in that chest freezer and go in after it. Careful because holy hell does it hurt when you just like embed your face into just a blanket of co2 you'll pass out And this is actually how many people have died in fermenters when they've gone in to clean them

Yeah, you don't you don't actually taste it, but it burns your eyes. Oh, it hurts. I think that it burns when

you can't breathe it Yeah, so at least in that quantity

Breathe it but to no effect, right? Yeah And there are some non laughable stories in the last 10 years Modelo had someone go into a tank to clean it and the tank was full of CO2. They didn't have the right equipment. They passed out. One person follows them and next one followed. Six people died. They went into this tank to rescue one another. So this it's, it's a real dangerous issue in the brewing industry actually. But let's, let's get out of that. We

have safety things.

Yeah. Back when I was studying geology in my inorganic chemistry class, remember we had this really long thing. Where we had to explain the process by which CO2 became carbonic acid, right? in seawater. Is that process occurring in beer?

Allison can speak to that a lot, but you're, you're making carbonic acid and that's giving you a bite in the finished product. And that's, that in addition to the hop acids are giving you the balance you're looking for in the end result.

From my understanding, it's not very much, it's not a high concentration of carbonic acid.

Belgian beers, however, go double the carbonation of, of a normal, say, English ale. So you might see more in that case because it shifts that, that, chemistry toward carbonic acid away from CO2. I did want to say on the high alcohol that opens the door to talking a little bit about high, the effects of alcohol on bubbles. And they, and alcohol in, in water tends to change the. Can you speak to that?

No, I was like, have we even talked about bubbles yet?

Right. We've, we're kind of coming from it from the outside in, aren't we? So bubbles how do you make a bubble and how do you destroy it? I think that's probably the best way to. about bubbles and beer. My, my men, one of my mentors in brewing school was Charlie Bamforth and he's known throughout the beer world as the Pope of foam. So he's obsessed with foam and by proxy, I think I've, I've sort of become a little bit obsessed too. He's also a prolific writer of football, the, the, the worldwide version of football, but that's another conversation for another day. He, would describe bubbles and make you cry at the end of the day. I'll do my best here. Bubbles are protein related. There's a certain molecular weight protein that gives you the main amount of the main structure of these bubbles. Other elements to the story include like your double ionized. metallic ions like calcium, magnesium, and then you get in hop acids,

just stop talking

Starches. Yeah.

Wait. I mean, and I, I'm a chemist.

I don't have a picture in front of me, but yeah,

Let me, let me try. so imagine you have a balloon and you blow up that balloon, you have essentially a bubble. And so what happens is imagine now that the proteins and all the molecules Bobby just mentioned are holding hands in this nice kind of tight way and then gas. As in, when you're putting air into the balloon, expands it out. So that's what's happening is the CO2 is encased within these really well connected structures. And so they're just really molecularly sticky. And so those proteins are love, well, and this is what gluten is very sticky molecules. Anyway, and so the CO2 gets trapped within these molecules that won't let it escape because CO2 wants to escape. This is why if you leave your beer out for any length of time, it's going to get flatter and flatter. Flat means no CO2 anymore. And so because those CO2 molecules want to escape, they are trying to, but they can't because those proteins are essentially holding them in and not letting them escape very well.

There's also that Henry's law we spoke about too that there's a natural amount of co2 that does remain at the end of the day Yeah,

it seems you're talking about there's two different types of bubbles. There's bubbles in foam, but then there's the bubbles that come up from the bottom or the sides of a glass, right?

So that's so that's the co2 itself evolving in order to capture it. You have to create these these Structures that I mentioned the compounds involved and then Allison mentioned how co2 likes to leave that solution Well, you can think of the walls of these bubbles as being Very thin layers of beer and so they might actually coalesce that is one bubble becomes to become one They gas passing from one of the to the other

But the proteins aren't those are strong more strongly Connected to the water and when I say water I'm talking about beer So the proteins are more strongly connected to the beer, which is why when you have Bubbles, they're not going to form like soap bubbles that then rise up and then go float away. Because those proteins are still strongly connected molecularly to the beer itself.

Yeah, proteins are not evolving away. CO2 is. And as the dry, I call it dry, dry foam. Sometimes people will see me messing around behind the bar and it takes me forever to pour beer. It's not because I'm just trying to get the perfect shot for a, for a magazine. It's because I'm letting the, the beer drain out of the channels between all the bubbles. And as the beer drains out, what's left behind is the, is the protein and the hop acids and the metal acids. that are calcium ions, which is really what they are that are giving that structure. And then I'll pour beer back on top of that. Again, I'll do it three or four times. And if you're patient enough, I'll do it seven times and it'll come out like the, like a meringue. And if you've ever made pies and you've made your meringue that you're working with proteins there, you're the albumen of a, of an egg. So that's what I'm doing back there. I'm trying to drain the beer off, make the bubbles have more integrity. And then the lacing will be profound after you are finished drinking that.

We try not to let him loose in the tap room too often.

Well, there was one more thing we should mention and we're right here on we're hovering on it Co2 and how it likes to escape nitrogen doesn't like to escape So these little bubbles when adjacent to one another will remain adjacent to one another will not coalesce So you have a very creamy foam top of your guinness because it's full of these nitrogen bubbles That have no means of coalescing and going away that that's the whole Story behind nitrogen.

I'm giving Bobby the look that says you are absolutely wrong in what you just said So nitrogen does want to escape the liquid so it doesn't actually want to stay because it's nonpolar,

Right, so but it can't pass through the the boundaries that separate the bubble that you are correct. So they Yeah, yeah, there's two parts of the story. So it has to get out of the beer Yeah, but as soon as it encounters these films It's at the surface of the beer. It's a prisoner throughout the pint.

And it's much smaller. The size of the bubble is so much smaller for nitro based beers or nitrogenated beers than it is for CO2. Okay.

So let's back up about this. You serve several nitro beers. Yes. How does the nitrogen get in the beer?

Oh, we put it there. Kind of.

So I'm just saying in the natural fermentation process, right, this is not something that is story.

Yeast aren't pooping out nitrogen. Right.

Right. So. How do you do it? Because I know it's not just in beers. Pepsi's come out with like a nitrogen version.

Wait, what? Are you serious? Yeah.

You didn't see this? There's like Pepsi nitro.

Oh weird.

Yeah. So it's, it has a different feel and everything else. Where does the nitrogen come from?

So we can't, we can't tell this without talking about Guinness. they can, they decided, so we make a lot of Cascale here and that's the old way of doing it. And you put beer into a keg, if you like, and you add yeast and sugar and you let it referment and create its own carbonation. And that's how it was done in the old days. And then you serve it through these water well type handles that we call beer engines and people still celebrate today. Okay. As being part of the old way of making beer. And that makes a creamy little foam because of the way it's, that you disperse it through the tips of the system. And it's, and it looks a lot like nitrogen. And in reality, the story goes the other way. Nitrogen looks a lot like cask. Guinness decided it didn't want to do that much work. It's a lot of work to do cask.

So much work that we are, one of like three or four in the country that actually specialize in cask conditioned ales, whereas in England, everyone does, but here, not so much.

Less and less in England, but that's a, Maybe it's changing. It is a pain in the ass though. But, I'm not sure where that came in, but I just wanted to bring it up that Guinness came up with nitrogen. That's where it came from. It's an industrial addition to the process. And, Today, how do we do it in our brewery? We bought our entire brewing system for two reasons. One reason where they came, it came from the Czech Republic. Ultimately, maybe we'll talk about our system in the future episode, but, one reason was so I can make German lagers with it. And the other reason was so I can make Irish nitro. The equipment is set up. To take on more pressure, I can take advantage of Henry's law and I can actually put nitrogen into a state in which it likes to be dissolved in the beer. And then from there we can package it and deliver it through the standard nitro setups. But not many people have the equipment that can go to those pressures. But I knew that these would be the linchpins to what we would be serving down the road.

Cask beers, which you mentioned, if they go through the same fermentation process, why are they flatter? or taste flatter. Why isn't that they don't have the same level of carbonation that you find in say a lager?

Because they are superior. Okay.

Most days you'll see me drinking our English IPA. I like the mouthfeel there. The reason though that they are that way is because they are at atmosphere. And they are at 50 degrees. So they are whatever Henry's Law say they are.

So Henry's Law will also say that, I mean, and this is the, the, like I said before, if you leave your beer or soda, out on the table it's going to equilibrate to room temperature. And so it's going to continue to get warmer and warmer until it matches room temperature. And then that's going to cause more and more of the CO2 to escape the beer. And so Henry's Law says more of the gas escapes at the higher temperature. But I think cask conditioning, that was how it was for the longest time. And so I think that the, the colder beers, we didn't have refrigeration all the time back in the day.

Cellars.

Yeah. So the cellar temperature is what they had. Cause the casks were way down at the bottom in the basement cause it kept it cooler. And so that's one of the reasons that they had the hand pump technology. And the folks that used to do this were called. publicans and they would work to tend to the pub or tend to the firkins or the cask conditioned ales. But one of the things about the casks is that it simulates what beer would have been. And so back in the day when we didn't have the technology to have really high pressure CO2, because under high pressure is not only expensive, but it's also dangerous. And until we had the infrastructure to build these huge tanks to CO2 and regulate pressures and stuff, it was way too dangerous to have anything in a wooden barrel to be under high pressure. Actually, you really even couldn't because you couldn't seal it enough.

First, where do you get it? And then how do you purify it? How do you transport it? How do you integrate it? Yeah. These are all industrial developments and, and everything was, was, quote cascadged at some point in the last before 150 years ago, for sure. Everything was. Yeah. Yeah.

So, in a cast, is it literally just flat, so far as the carbonation has escaped?

So no, actually this is a process. So we, we have behind us down the hall, we have, probably 50 Perkins, which are large casks ready to be tapped. And when you tap them initially, you can't serve them because they have to do a, go through another stage of what we call venting. They have to reach a Beer is just like people.

We all need to vent, don't we?

So that takes about a day, if not longer. Sometimes you get lucky and it's a few hours, but usually it's going to be a little angry, little about the change.

Were the, let's go back 150 years ago or 200 years ago, were the casks still there? They were all just wooden barrels at that point.

They would have been pitch lined. So like sap lined to keep them airtight. Yeah.

Didn't know. Mm hmm. Because now we use these metal for can things, the metal casks and those are gloriously sealed.

Yeah. They were, they're glorious. He's gloriously sealed then too, but you know, this is a time before microbiology. So there's a lot of bacteria and a lot of contamination. We call it house character. But yeah. But to Gary's point though, that reaches a certain. Level of carbonation finds equilibrium with the atmosphere putting in, it's not an entirely reversible process. Allison knows more than me, but putting the CO2 in and then, and then coming back out, those are different in terms of time scales and levels. But you get, you get sort of, an artistic, input on the whole process as a publican. I wish that would come back because we would have more accounts around the state, people that knows how to handle these cascades.

But to Gary's question, are casks flat? The answer is that they are flatter than lagers. But they shouldn't be completely flat as in have no CO2 at all. There is going to be some amount. It's just going to be smaller than you're used to.

The lowest carbonation beer that we make, beers that we make are nitro beers, but believe it or not, they have, they themselves have carbon dioxide in them.

Even more so than our imperial stouts?

Oh gosh, imperial stouts have three times as much as our nitro. Yeah. It's just that there's so much sugar in our imperial stout.

Calculating out how much carbonation, are you just saying that nitrogen, because it's nitrogen, doesn't contribute to carbonation?

Nitrogen does not contribute to carbonation.

Right. But it's still, so, it's nitrogenated versus carbonated.

Yeah, it's about...

so that's not fair. It's a different gas. That's cheating.

One, one thing about nitrogen is, you guys wouldn't believe it, you could hold in your hand how much nitrogen goes into 600 gallons of, of nitro beer.

Yeah. I would totally believe it. Molecules are small.

It's astonishing. Well, but by comparison, you're talking about thousands of times more for CO2.

Well, yeah. It's bigger.

But the effect of that tiny amount of nitrogen, it's parts, it's 40 parts per million. And Guinness revealed this recipe on their, somewhere in their history, in some scientific paper. And sure enough, if you go 35, you don't get the cascade. You go 45, half your glass is full of foam. It's remarkable. It's, it's incredibly small amount, but nitrogen, this whole, this whole science of beer gas is, is fascinating

to some,

to some.

No, it really is fun. And if you have the opportunity to try, a regular tap beer, a nitro beer and then a cask beer all at the same time. It's really fun to just to feel the different mouth feel that you get from the different bubbles.

Are there any other gases that you could use? Is nitrogen pretty much it? And is it, does the fact that it's inert, well, relatively inert, a nitrogen molecule have to do with its use?

Yes. but April 1st is coming, so we should do that helium beer. I think that should happen because I want to see, there was a, I think Sam Adams did this a couple of years, it's been a decade ago. They, they joked about doing it and they were standing around drinking it and then talking like they had consumed a balloon. Yeah. But

I would say like the closest relatives to co2 is like so2 and you would not want sulfur dioxide in your beer at all nitrogen, i'm trying to think who the closet

relative although sulfur dioxide preserves the beer It would be disgusting to

So gross. No, don't do that. but no I think conveniently you don't want oxygen in your beer that's going to cause a bunch of extra reactions to occur oxidizing, that sort of thing. You definitely don't want chlorine in your beer, cause that'll kill you. And chlorine's even worse. Die faster. So, don't do that.

In theory, could you take a heavier, inert gas, like neon?

Ha ha, that'd be fun. I don't see why not.

I mean, it'd be kind of expensive.

Yeah I mean, it would,

I like where we're going here.

No, I don't. well,

Five gallons of this.

It's to throw Argon in. Why not? Krypton, that'd be fun.

Argon would be cheaper.

It would. I think you, no.

Food grade Argon. I'm gonna Google search that.

I'm about to look up Henry's constant on Argon. Cause, yeah, We use argon to like clean, clean different liquids and we'll bubble it through to like catch all the stuff as it bubbles out. I think the Henry's constant is just so big you wouldn't actually have any of the gas stay.

One other fascinating thing, I should, I should give this to this tidbit to the home brewers and the brewers out there. You actually do not want to see foam created in the brewing process or the fermentation process any more than is necessary because this is not reversible. These molecules that made that foam are lost forever for that application. So you see, And throughout your packaging and so on, you want to keep all your foam down as low as possible beyond just the loss of beer that's in involved. So yeah, that's that's chemistry. It only goes one way in that case.

So when you have you pour a beer, there's foam at the top. You let it sit for a little while. That foam will eventually go down and disappear. Is all that, I mean, that's obviously going back into the beer at that point.

No no. The proteins themselves

I mean it's got to go somewhere.

Well, you're probably consuming them in the first few sips. You're probably consuming most of that foam off the surface. The, the, the, the air that was holding them bubbles up, CO2 is now coalescing, gone to the atmosphere. So it might be a little bit misleading to, to interpret that much foam as actually being that much material. It might be 99 percent CO2. So when it does completely evolve, there's not much left to speak of anyway. But it does, it does give you that lacing on the sides, which is, Cathedral like, if you listen to Charlie talk about it. Yeah. Hedonic was the word we used. I'll never forget it. It's purely hedonic.

And Allison, do you have a calculation?

I'm trying, I'm looking, but the units aren't matching up, so I'm having trouble, because no one would ever put neon into liquid because that doesn't help anything. But Henry's constant is about 0. 03 for CO2, but then it's like 0. 0004. in neon, but the units are a little bit different. It's really, really small. So cause no neon wants to stay in any sort of liquid. So yeah, so brewers out there, sorry, please do not put neon in your beer.

All right. Well, is there any more on the subject of bubbles?

I have more than we have time for. I did want to mention decoction one more time. A decoction is the way that we handle grain. If you go at it from the German and the check way of doing things, you, you, you cook it and you can recombine it in the process. The point I wanted to bring up here though, is, is the heating and the pH that and the time duration that you apply on that barley and on that malt gives rise to different levels of molecular weight proteins. And ultimately, you can create amazing foam by doing decoctions. I'm always going to be a champion of decoction brewing for more than one reason.

I got nothing to say to that other than everyone doesn't like you at least in back of house because of the decoction.

Until I put the, the, the results in front.

Oh, it tastes so much better. It really does. But the process of it, well, it's kind of like, you know, when you, you know, you can bake bread. you know, at home by yourself. And like, you know, it takes all this time, or you can just go buy a nice bread loaf. But then again, I guess that's what we're in the business of is making liquid bread.

The team in the back of the house are very pragmatic. They say if it makes the beer better, they'll do it. And we put the test in front of them. And if it, if it's better, they will jump right in.

Unless it's the 36 hour brew day, which is our Mike Santos, Ph. D.:

Including that one, too. They'll do that too.

Yay for bubbles.

All right, well that concludes another episode of Respecting the Beer. Join us next week and until then, please visit us over on our Patreon page or over at the Facebook group links of which can be found in the show notes.