Scientists study "triple-fermented" Belgian beer...?

[sibelman]

"... the degree of fermentation—i.e., whether a given beer has been singly, doubly, or triply fermented—is crucial" to stable foam.

So Belgian tripel is triply (is that a word?) fermented. Who knew?

https://arstechnica.com/science/2025/08/physics-of-why-belgian-beer-foam-is-so-stable/

 

[Hoochin'Fool]

I read that this afternoon. Maybe I just didn't understand it (I was mindlessly scrolling on my phone this afternoon), but that was completely devoid of any useful information.

 

[Miraculix]

I read that this afternoon. Maybe I just didn't understand it (I was mindlessly scrolling on my phone this afternoon), but that was completely devoid of any useful information.

Sounds like an ai article to me...

 

[worlddivides]

Sounds like an ai article to me...

That is DEFINITELY an AI article. The whole idea of singels, dubbels, and tripels being "singly," "doubly," and "triply" fermented is just... bizarre. That makes it sound like triple distillation, but just a tripel is fermented three separate times.

Even that image with the caption ""Foamy!" Much of the pleasure from beer comes from a nice thick head of foam." Oh, really?

 

[Zadkiel]

oh no. Is it too late for me to add 3 more yeasts to my quad in the fermenter? Does using a bottling yeast like CBC-1 count as one of them?

 

[Northern_Brewer]

With anything vaguely scientific, I just skip the article and go straight to the underlying paper, which is here :

https://pubs.aip.org/aip/pof/articl.../The-hidden-subtlety-of-beer-foam-stability-A
They're looking at the physics of Tripel Karmeliet and Westmalle Tripel/Dubbel/Extra (="singel"). They're material scientists rather than beer experts, so expect them to swallow the conventional stories about how Belgian beers are named, and to concentrate on the romantic stuff rather than the fact that they have higher OG and so more protein and other stuff in the glass. Short version is that there's two different mechanisms in foam formation, one that dominates in lager and one that dominates in top-fermented beers, and you get more of the latter in the higher ABV/OG tripels versus the singel/dubbel.

our study clarifies the physical mechanisms behind beer foam stability, demonstrating for the first time that Marangoni stresses in beer foam are as influential as surface viscoelasticity, it does not resolve why Lagers and Belgian ales differ in composition or foam properties, apart from implicating their distinct fermentation methods. Nonetheless, irrespective of the underlying cause, our findings offer a valuable roadmap for enhancing foam stability...

By adjusting the size of bubble nucleation sites in the glass, we can control bubble size...

Second, it is clear that increasing foam stability by implementing strategies related to enhancing the surface viscosity, such as increasing the hydrophobic character of the foam-promoting proteins,127,128 adding iso- -acids129 or propylene glycol alginate,10 and manipulating metal ion concentration,130 is most effective in Lager beers and not in beers that show Marangoni stabilization, such as the Belgian ales studied here. For the latter, controlling proteolytic activity to reduce the hydrophobic character of proteins131,132 seems a more promising strategy.

It might seem that the simplest solution for optimizing the film and foam stability is to denature proteins as much as possible. An easy way to cause the denaturation of the proteins in our experiments is by letting the beer films age overnight while at equilibrium. This process led to very stable and thick films for both Tripel1 and Lager1...

Finally, our results explain why the effect of lipids on beer foam may not always be clearly detrimental.137,138 In Marangoni-stabilized beer foams, such as those of the Belgian ales, lipids are not expected to have a catastrophic effect, in contrast to Lager beers whose foam is stabilized by surface viscoelasticity.....

Beer foam stability is closely tied to beer type: lager (or low fermentation) beers are primarily stabilized by surface viscosity or subtle viscoelastic effects, rather consistent with earlier studies,6 while triple fermentation Belgian ales are stabilized by Marangoni stresses. Notably, Belgian ales, especially those undergoing multiple and prolonged fermentations, exhibit enhanced foam and film lifetimes due to these strong recirculating Marangoni flows.

 

[Snuffy]

There is a point when close examination becomes buzzkill.

 

[shoengine]

I hope Ars isn't stooping to using genAI to write articles. I stopped reading that site half a dozen years ago or so, but it was formative for me back in my youth.

 

[sibelman]

They're material scientists rather than beer experts

Arstechnica AI or not, I assumed that lack of beer knowledge was the source of the phrase "triply-fermented."

Notwithstanding, there's some interest in the underlying science. Thanks for unearthing and extracting from that, @Northern_Brewer.

 

[Zadkiel]

"triple fermentation Belgian ales"

if a science paper on effects of lasers talked about changing the laser colour by swapping the laser lizard to one with different coloured eyes, I think I'd question the results, even if understanding how laser colour changes wasn't necessary to interpreting the results.

 

[mac_1103]

if a science paper on effects of lasers talked about changing the laser colour by swapping the laser lizard to one with different coloured eyes, I think I'd question the results, even if not understanding how laser colour changes was necessary to interpreting the results

What exactly do you have against laser lizards?

 

[mac_1103]

Anyway, the paper isn't about how Belgian ales are made and understanding how they are made isn't actually relevant to the question addressed, the methods used or the results obtained, and it only impacts the interpretation of the results to the extent that they mistakenly ascribe the differences in physical and chemical properties of the ales to different numbers of fermentations rather than the composition of the grist. You don't have to know the difference between ales and lagers or dubbels and tripels to be able to analyze the differences in physical and chemical properties of commercial examples of each. But yeah, they should have consulted an actual brewer or two and gotten the background right. And I guess that I'm also a little bit surprised that none of the reviewers or editors seem to know what a tripel really is either.

I'm not going to read it even though I think it's probably pretty fascinating. But that's because fluid dynamics is way the hell over my head, not because I distrust the results.

 

[Zadkiel]

What exactly do you have against laser lizards?

some of my best friends are laser lizards!

 

[MaxStout]

I hope Ars isn't stooping to using genAI to write articles. I stopped reading that site half a dozen years ago or so, but it was formative for me back in my youth.

AI might bring an improvement to Ars Technica's "journalism."

 

[Snuffy]

Wait... does this mean I'm not supposed to pitch 3 times for a tripel?

 

[shoengine]

AI might bring an improvement to Ars Technica's "journalism."

Evidently not.

 

[AmarikinBrew]

I've been guilty of sending 22 fl oz over my tonsils very quickly. This is also beer fluid dynamics?

 

[Broken Crow]