Shower Thoughts on Brew Science

[VikeMan]

But in this case, the Dolium graph provides experimental evidence that O2 is getting into carbonated beer sealed inside the package.

I think the graph shows the intial headspace O2 dissolving into the beer over time, offset by oxidation. I don't think it demonstrates anything one way or the other about the rate of O2 through the package walls, because that effect is swamped by what's happening during the time covered by the graph. If they continued measuring until point-in-time dissolved O2 stopped decreasing, that could indicate something about how fast O2 is getting in.

 

[frithy]

Vikeman, AlexKay, thank you both tremendously. I was just trying to find whether permeability of PET would require pores or could work like a liquid and then AlexKay gave an answer. Then, I wanted to use Vikeman's argument on there being oxygen in the headspace as a possible rebuttal to the experiment showing o2 ingress, but he beat me to it.

An interesting experiment would be to simply take a few PET bottles of a liquid that changes colour when oxidized and add some some yeast and sugar. Then, as a rough control, add the yeast but not sugar to some other bottles of the same liquid. After a few months, see if there is a difference.

Or, even better, use a co2 tank instead of priming to make it far clearer whether it was the co2 that was responsible.

Hell, doing both would be the most telling as it could possibly show some additional benefits of priming vs forced carbonation.

 

[Miraculix]

I've used to squeeze out any air of a beer filled pet bottle, closed it without air inside and let it carbonate naturally with priming sugar. 2-3 months later, oxidation was clearly detectable.

 

[mac_1103]

An interesting experiment would be to simply take a few PET bottles of a liquid that changes colour when oxidized and add some some yeast and sugar.

Knock yourself out.

 

[frithy]

Shower thought:

• Were all historic beers more or less what we now call sours? Was all leavened bread sourdough? How could they not be? Are modern traditionally made farmhouse ales all a bit sour? Are maltøl and kaimiškas sour? hmmm

edit - historic meaning before the 19th century.

 

[mac_1103]

Were all historic beers more or less what we now call sours?

Maybe eventually, but probably not if consumed fast enough.

Was all leavened bread sourdough?

Doubtful since the leavening process is different. Making sourdough isn't just a matter of intentional or unintentional contamination.

Are modern traditionally made farmhouse ales all a bit sour?

I could be wrong, but I thought that was the point.

 

[frithy]

Maybe eventually, but probably not if consumed fast enough.

That's what I'm thinking after reading this:
https://www.brewingnordic.com/farmhouse-ales/norwegian-farmhouse-ale-hornindal/
"Although this kveik is known to contain bacteria, I didn’t sense any sourness in the fresh ales. One several months old maltøl, which was brought just to educate me, tasted slightly tart, but not sour. It was not bad, though clearly inferior to the fresh ale."

So, I'm guessing before pasteurization beer was normally brewed hot and fast similar to modern kveik. The further you got from the pitch date, the more sour your drink. That makes me wonder if the pre-modern lagers were a generally tart beverage.

 

[frithy]

Shower thought:

• Why hasn't anyone created a submersible oxygen absorber? All you'd need is to put iron powder or some other oxygen reactive substance in a container that readily lets o2 pass but doesn't let the iron. It could be like the Guiness nitro balls. Million dollar invention.

 

[frithy]

Shower thought:

• Why doesn't anyone use mucilaginous plants to add body to a beer? If fermenting a style that demands body but using a highly attenuating yeast, couldn't you just add something from the mallow family to add mouthfeel? Why isn't this more common?

 

[VikeMan]

• Why doesn't anyone use mucilaginous plants to add body to a beer? If fermenting a style that demands body but using a highly attenuating yeast, couldn't you just add something from the mallow family to add mouthfeel? Why isn't this more common?

"More common" implies that someone has already done it at least once.

My guess as to why nobody does this is that it would also bring other compounds, with unknown and/or suspected/known undesirable consequences. Clorophyll anyone? Yum!

BTW, there are other well tested ingredients (e.g. oats, or pretty much any unmalted grain) that can be used to enhance mouthfeel, even in a highly attenuated beer. And, some very highly attenuative yeast strains, such as saison strains, produce significant amounts of glycosides, making a mouthfeel that belies the dryness of the beer.

 

[frithy]

"More common" implies that someone has already done it at least once.

My guess as to why nobody does this is that it would also bring other compounds, with unknown and/or suspected/known undesirable consequences. Clorophyll anyone? Yum!

BTW, there are other well tested ingredients (e.g. oats, or pretty much any unmalted grain) that can be used to enhance mouthfeel, even in a highly attenuated beer. And, some very highly attenuative yeast strains, such as saison strains, produce significant amounts of glycosides, making a mouthfeel that belies the dryness of the beer.

Yeah, I added that "common" to hedge my bets. I didn't want a reply of "What are you talking about? Adding x is standard practice when making a Lilliputian pale ale."

As for other compounds, that's why I mentioned mallow. The roots of one bog-loving species were traditionally used to make a well-known treat and are reported to have only a mild and pleasant earthy flavour.

In regard to using oats and such, I had the idea because I'm wanting to use 100% rice to brew an ale.

 

[frithy]

Shower thought:

• What is the point of headspace in the bottle? I tried to find an answer, but all I could find were people saying not having it could cause the bottle to explode. I don't get the logic for that though. Isn't the pressure of the air in the headspace simply going to stay constant for whatever level of carbonation the beer is? So, why leave headspace?

 

[day_trippr]

Well...without at least a little headspace it would be challenging not to get wet when popping the cap.
Beyond that it's all mystery to me, so I switched to kegging

Cheers!

 

[doug293cz]

Shower thought:

• What is the point of headspace in the bottle? I tried to find an answer, but all I could find were people saying not having it could cause the bottle to explode. I don't get the logic for that though. Isn't the pressure of the air in the headspace simply going to stay constant for whatever level of carbonation the beer is? So, why leave headspace?

With zero headspace, pressure from thermal expansion of the liquid can become very high, and cause bottles to burst, or caps to pop. It doesn't take much headspace to provide room for the liquid expansion - 1/4" should be more than enough. You are correct that the pressure in the headspace will adjust to maintain equilibrium with the carbonation level of the beer as temperature changes.

Brew on

 

[frithy]

Well...without at least a little headspace it would be challenging not to get wet when popping the cap.
Beyond that it's all mystery to me, so I switched to kegging

Cheers!

Haha, I hadn't thought of that. Good point.

With zero headspace, pressure from thermal expansion of the liquid can become very high, and cause bottles to burst, or caps to pop. It doesn't take much headspace to provide room for the liquid expansion - 1/4" should be more than enough. You are correct that the pressure in the headspace will adjust to maintain equilibrium with the carbonation level of the beer as temperature changes.

Brew on

Yeah, wow, I hadn't even considered thermal expansion.

Thanks for the replies, guys.

 

[mac_1103]

without at least a little headspace it would be challenging not to get wet when popping the cap.

also kinda hard to pour without spilling

 

[duncan_disorderly]

Oxidation remains a bit of a mystery to me. Experience suggests that naturally carbonated beers resist it much more successfully than force carbonated beers. I am a rudimentary type of brewer, big pan, bag, bucket, bottles. No closed transfer, pressure fermenting etc. Its all beyond me.

In fact I do the unthinkable and fill bottles with a jug. I did use a bottling stick for a while but got fed up with it. So my beer must be oxidised surely. Well, not to an extent that adversely affects my pleasure. And probably not much at all. I only once entered a competition and my beer placed second out of 20+.

One judge's score sheet remarked that there was no oxidation in my beer and this was unusual in their experience if judging home brew. The judge was the quality control person for one of England's top rated breweries. I spoke to her after and didn't dare tell her about my technique. She told me she thought my beer was the clear winner, and should have won. It was good for my confidence cos I don't feel confident about my brewing, given how non technical it is.

How can such rudimentary technique produce an apparently oxygen free beer? It had been bottled, in glass, for approx 3 months. I don't use PET cos they lose carbonation, if nothing else.

I prefer naturally carbonated beers to force carbonated. It's also virtually free CO2. It reduces oxygen risk too, and the need for additional equipment and the transporting around the nation of huge amounts of gas in tanks.

 

[frithy]

Shower thought:

• Why not take a few diverse yeasts and throw them into a starter with some lysozyme. Once you have your protoplasts, add some PEG. Shake or stir it up and then let it recover. Bam, sundry new yeast strains. Maybe get creative and add some live hop material in with it before the lysozyme. Suddenly, you have yeast making their own hop oils. Billion dollar idea.

 

[Bassman2003]

Some random thoughts:

• Everywhere says the pressure of an active fermentation keeps oxygen and infections from getting in during brewing, but why wouldn't the carbonation pressure also prevent oxidation in plastic PET bottles? Is there any evidence at all that carbonated PET bottles get oxygenated?

• The environment is full of microorganisms. Without laboratory grade control, every single beer is definitely heavily infected. Before the advent of the modern yeast industry, the entire process would have been incredibly biologically diverse. Yet, beer has been with us since prehistoric times and all around the world in every environment. So, is it possible that obsessive sanitation is all pointless and the only true problem is exposure to oxygen?

Once you pitch your yeast it is a race between the bad stuff and the yeast to grow in numbers to win control of the wort. Sanitizers give the yeast a head start as the bad stuff grows faster than the yeast. Once the yeast takes hold, it drops the pH of the wort and creates a hostile environment for the bad stuff. so sanitizers are very important. We need the O2 for a small window to help with yeast health/growth.

 

[Bassman2003]

Oxidation remains a bit of a mystery to me. Experience suggests that naturally carbonated beers resist it much more successfully than force carbonated beers. I am a rudimentary type of brewer, big pan, bag, bucket, bottles. No closed transfer, pressure fermenting etc. Its all beyond me.

In fact I do the unthinkable and fill bottles with a jug. I did use a bottling stick for a while but got fed up with it. So my beer must be oxidised surely. Well, not to an extent that adversely affects my pleasure. And probably not much at all. I only once entered a competition and my beer placed second out of 20+.

One judge's score sheet remarked that there was no oxidation in my beer and this was unusual in their experience if judging home brew. The judge was the quality control person for one of England's top rated breweries. I spoke to her after and didn't dare tell her about my technique. She told me she thought my beer was the clear winner, and should have won. It was good for my confidence cos I don't feel confident about my brewing, given how non technical it is.

How can such rudimentary technique produce an apparently oxygen free beer? It had been bottled, in glass, for approx 3 months. I don't use PET cos they lose carbonation, if nothing else.

I prefer naturally carbonated beers to force carbonated. It's also virtually free CO2. It reduces oxygen risk too, and the need for additional equipment and the transporting around the nation of huge amounts of gas in tanks.

Oxidation is very subjective in a brewing context. One has to learn to pick it out then learn how advanced it may in in that certain beer etc... It takes a long time to figure out imho. But first, one has to realize that most all homebrew is at some degree of flavor threshold of being oxidized due to process. Hot side and the cold side. I like to think of non-oxidized beer as "pure". Pure as in the true flavor of the ingredients are presented with any degradation or replacement.

After learning to brew lower oxygen over the past four years, I can not for the life of me figure out why this topic offends or makes people so defensive. The pursuit of the best brew possible is noble isn't it? To search for this is to admit current shortcomings in process and technique. Maybe that is a sore spot?

Anyway, the reason naturally carbonated beers are better in terms of oxidation is the active yeast eat the oxygen and bottled CO2 has some oxygen in it. Natural wins every time. Every beer fights that battle of oxygen ingress. All efforts are just ways to limit damage and slow down the inherent slide into the abyss.

In my experience, slightly oxidized is just that, slightly. Meaning beer can still be enjoyable with varying amounts of the stuff. I am guessing what that judge meant was many of the beers they were tasting were far past slightly oxidized. I brewed that way for 16 years while always trying to improve various processes. I wish oxidation avoidance was mentioned and taught from the beginning as it would solidify better practices than the myriad of homebrew dogma that has existed over the years.

It is your hobby and your beer, so nobody can tell you what is best for your tastes. But, others' can point out better practices and techniques for obtaining a more "pure" beer. Whether or not that is important to you is down to your interest etc...

 

[mac_1103]

After learning to brew lower oxygen over the past four years, I can not for the life of me figure out why this topic offends or makes people so defensive.

Yeah, why on earth would anybody be offended or get defensive when someone who's never tasted their beer tells them that their beer sucks?

Non-sarcastic version - it's not the topic, it's the tone.

 

[Bassman2003]

Understood. I hope any kind of tone is not picked up in my posts. Internet forums are horrible when it comes to communicating tone etc...

 

[mac_1103]

I hope any kind of tone is not picked up in my posts.

Not at all. Just a general observation.

 

[Bobby_M]

After learning to brew lower oxygen over the past four years, I can not for the life of me figure out why this topic offends or makes people so defensive.

A combination of ego and Dunning-Kruger and it's basically applied to any aspect of brewing that may make a quality difference depending on sensory threshold. There's also growing general distaste for elitism across the board.

We're all guilty of being wrong on both sides of the argument.

 

[VikeMan]

There's also growing general distaste for elitism across the board.

If by that you mean there's a growing taste for "short and shoddy," I would tend to agree.

 

[mac_1103]

There's also growing general distaste for elitism across the board.

I don't mind when someone who really does have an elite level of knowledge of a subject shares it. Even if that person acts like a self-important condescending elitist I can still learn something (assuming I'm in the mood to ignore the self-important condescension).

We're all guilty of being wrong on both sides of the argument.

Can't really argue with that.

 

[Bassman2003]

I can't disagree. Trying to avoid this sliding down a hole but how information is presented does not change whether or not it is correct. It seems a lot of feathers were ruffled in the past in the effort to bring correct brewing knowledge to the homebrew world. I say correct because it is applied and used at the highest levels of the industry. That might not fit hobby style brewing needs, but it is still best practice, solid science brewing process.

 

[mac_1103]

I can't disagree. Trying to avoid this sliding down a hole but how information is presented does not change whether or not it is correct. It seems a lot of feathers were ruffled in the past in the effort to bring correct brewing knowledge to the homebrew world. I say correct because it is applied and used at the highest levels of the industry. That might not fit hobby style brewing needs, but it is still best practice, solid science brewing process.

Absolutely. And then everybody gets to do their own cost/benefit analysis. "That's not worth it to me" shouldn't be presented as "you're wrong" anymore than "here are some effective ways of reducing dO2" should be presented as "you can't make drinkable beer unless you do what I say."

But anyway, I didn't think of any of this in the shower this morning, so we should probably try to get back on topic.