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Foam and time, what is the connection?

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FWIW, here's a pic of the oatmeal stout pour I'm enjoying now. A few minutes after I took this pic, the head dissipated to almost nothing. But the stout tastes great, with good aroma and mouthfeel, so I'm not terribly disappointed. Besides, I brewed this for my wife's birthday (one of the few beer styles she really enjoys), and she couldn't give two shiats about the head retention. Still...it kind of bugs me.
View attachment 759903
Wait two to three weeks and let's see how it looks then.
 
By the image you posted, it looks like the glass isn't "beer clean". The bubbles seem to be sticking to the side of the glass which is a tell-tale sign that there is some film on the interior surfaces.

This is an old but very good article which illustrates what I'm saying.
https://crescentcitybrewtalk.com/beer-foam/
This might the issue sometimes, but at least for my beers, I can rule that out completely, as it is always the same. First few weeks zero foam, afterwards good to great foam, depending on the recipe. I always use the same glasses and cleaning regimes. To me the beer on the picture looks axactly how my beers look within the first few weeks. Big bubbles that won't last.
 
Over the years I've noticed that it takes about 2.5 to 3 weeks in the bottle to get that whipped cream head that most any brewer would be proud of. Kegged beer takes a little less at around 2 weeks. I really can't find an answer. It isn't really a matter of carbonation but conditioning; not the same thing.
 
This paper is a bit more up to date. A little bit. I enjoyed the 2nd paragraph, where the reader is informed of the authors’ intention, in the name of science, to go out on the piss to record detailed observations of beer foam behaviour in the real world, outside the lab. They clocked off Friday lunch time and were on the lash until 3am Saturday morning. Sadly, the research never got published. They left all the data in a Chinese takeaway.
 
1939 Fuller's OBE. Base malt, flaked maize plus some flaked barley because I ran out of the maize to make 15%. <5% invert sugar.

10 days, carbed enough.
20220224_142731.jpg


3 weeks.
20220313_160423.jpg
 
I see this all the time in kegged beers, if in a slightly different way.
At first, I will get large bubbles when I pour. The beer is carbed fine, but when CO2 comes out of solution either on the pour or sitting for the 13 femtoseconds it sits in the glass, the bubbles are large.
A couple weeks later, near the end of the keg, the bubble are TINY. There are more of them, but they are minuscule, multitudinous, and marvelous.
 
I asked a pro brewer about this and his response was:

"My take is that CO2 gets dissolved into beer and then takes a while to become carbonic acid (H2CO3). My opinion is that when H2CO3 forms, over the course of several days, it will result in the small, champagne-like bubbles that signal a well-carbonated beer, similar to bottle conditioned Duvel. Prior to becoming H2CO3, the CO2 is not fully dissolved and the beer can have a slight 2-dimensional flat texture. After becoming H2CO3 the beer takes on a whole new texture that is richer and more enjoyable."

It makes sense to me as it seems to follow what I've observed but didn't understand.
 
I see this all the time in kegged beers, if in a slightly different way.
At first, I will get large bubbles when I pour. The beer is carbed fine, but when CO2 comes out of solution either on the pour or sitting for the 13 femtoseconds it sits in the glass, the bubbles are large.
A couple weeks later, near the end of the keg, the bubble are TINY. There are more of them, but they are minuscule, multitudinous, and marvelous.
Yes, I've witnessed the same. First big bubbles that go quickly and then tiny bubbles that stay much longer. I think this shows that there are some changes happening on the chemical level. The more hydrophobic polypeptides are available, the smaller the bubbles and the longer the foam stays. Bubble size has somehting to do with surface tension I believe. So it looks like during that time the beer just sits there more and more hydrophobic polypeptides seem to become available. I do not know if they are bound by something before, or if they are somehow created. Or maybe there is some foam decreasing agent in the beer that falls apart with time? Who knows.

I asked a pro brewer about this and his response was:

"My take is that CO2 gets dissolved into beer and then takes a while to become carbonic acid (H2CO3). My opinion is that when H2CO3 forms, over the course of several days, it will result in the small, champagne-like bubbles that signal a well-carbonated beer, similar to bottle conditioned Duvel. Prior to becoming H2CO3, the CO2 is not fully dissolved and the beer can have a slight 2-dimensional flat texture. After becoming H2CO3 the beer takes on a whole new texture that is richer and more enjoyable."

It makes sense to me as it seems to follow what I've observed but didn't understand.
I am not 100% sure but I think this is not how it works. CO2 solved in water is carbonic acid. It does not have to become carbonic acid over time, it instantly is carbonic acid as this is the mechanism of solution itself, which turns CO2 into carbonic acid. I think the reason for foam anhancement over time has somehting to do with those hydrophobic polypeptides.
 
I am not 100% sure but I think this is not how it works. CO2 solved in water is carbonic acid. It does not have to become carbonic acid over time, it instantly is carbonic acid as this is the mechanism of solution itself, which turns CO2 into carbonic acid. I think the reason for foam anhancement over time has somehting to do with those hydrophobic polypeptides.

The key here is "dissolved in water".
 
I have a theory. Can you guys please tell me if you normally use Irish moss or whirlfloc during your boil and if you experienced the delayed foam creation or not within your brews?

My guess is that positively and negatively charged molecules drop out of solution over time. Whirlflocc and Irish moss speed up this process so people that are using these shouldn't experience this foam delay at the same degree than people who are not using it.

I'm using Irish moss for the first time ever in my current batch so we will see what's going on in this one batch soon.
 
I use Irish Moss regularly. For ~4G post-boil, 1/2tsp hydrated in wort, added at 5min. Delayed foam retention +.
That doesn't sound so much. How much is this by weight? I used 3g on 18 litres. I boiled it for 15 minutes but it did not fully dissolve.

Thanks for the reply!
 
I can weigh it this evening. It's not something I concern myself with particularly. My 1/2tsp spoon is the largest that fits in the small jar of moss. Does it work? Is it enough? IDK.

Salts, hops, now AA. Those are are weighed with a gram scale.
 
1/2tsp = 1.3g

So, roughly 1/2 your dosage. Seems to work well enough. Or maybe that's just time in the bottle. ???
Thank you for checking. I am honestly not sure how much is the best ammount. I found different claims ranging from 1g to 5 g per 20l of beer...

I've seen some interesting claims about increased foam stability compared to non-moss batches.
 
I use 1/2 or 1 Whirlfloc with just about every batch.
I see the "finer bubble" syndrome near keg's end with just about every batch.
Can't say I see foam stability better or worse during the 4-10wk keg life.
 
The instructions on the label of Irish Moss I get at my LHBS say 1 teaspoon per 5 gals. This is in American measurements, 1 tsp = about 5 grams. This is what I use but I hydrate in a small amount of water the night before brewing.
The next day it looks gel like. I'm not sure about a foam delay but I use a Alpha rest @ 162 F and I prime with corn sugar. There might be a week or two before I get good foam. The Irish Moss seems to do a good job with protein coagulation.
 
The instructions on the label of Irish Moss I get at my LHBS say 1 teaspoon per 5 gals. This is in American measurements, 1 tsp = about 5 grams. This is what I use but I hydrate in a small amount of water the night before brewing.
The next day it looks gel like. I'm not sure about a foam delay but I use a Alpha rest @ 162 F and I prime with corn sugar. There might be a week or two before I get good foam. The Irish Moss seems to do a good job with protein coagulation.
I also saw this 1 tsp recommendation, in my case, this would result in less then a gram in my case as my irish moss is made of bigger pieces of the seaweed. I do not like volumetric meassurements of solids for obvious reasons.

Ok, but the main takeaway here seems to be that people are still experiencing this foam delay thing regardless of the usage of irish moss or not.
 
Ok, but the main takeaway here seems to be that people are still experiencing this foam delay thing regardless of the usage of irish moss or not.

FWIW and maybe slightly off topic, but here some recent anectodal observations of mine:

First thing, I also experience this delay in good head formation/retention, and I would also be very much interested to find out the reasons for this phenomenon.
I bottle condition all my beers.
Usually, the head starts to be quite good at 3 weeks post bottling. At 4 weeks it is good. At 6 weeks it is perfect.

A while back I started using Irish moss and I added it to 3 brews in a row. Then I went back to not using it for my last two brews.

If anything, it may have had the opposite effect (i.e., less head retention compared to my "standard"). But then again, it's difficult to say...for instance, I started experimenting with malted oats nearly at the same time, and I employed about 20% malted oats in 2 out of these 3 brews. It certainly could have had more to do with the malted oats than the Irish moss... .
In a recent brew I did not use Irish moss but did throw in some 15% malted oats. It also has somehow less head retention than what I'm used to.
I read that malted oats can be detrimental to head retention at large percentages, but it shouldn't be a problem at 15 - 20%...
Anyway, for the time being I decided on skipping both the malted oats and the Irish moss, and go back to my older ways. I have been chasing mouthfeel (hence the malted oats), but I also and absolutely want to keep the best head retention I can, as this aspect of beer is very important for me.

Anyway, long story to say that I don't think Irish moss has a perceptible impact on head retention, but I could be wrong.
 
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FWIW and maybe slightly off topic, but here some recent anectodal observations of mine:

First thing, I also experience this delay in good head formation/retention, and I would also be very much interested to find out the reasons for this phenomenon.
I bottle condition all my beers.
Usually, the head starts to be quite good at 3 weeks post bottling. At 4 weeks it is good. At 6 weeks it is perfect.

A while back I started using Irish moss and I added it to 3 brews in a row. Then I went back to not using it for my last two brews.

If anything, it may have had the opposite effect (i.e., less head retention compared to my "standard"). But then again, it's difficult to say...for instance, I started experimenting with malted oats nearly at the same time, and I employed about 20% malted oats in 2 out of these 3 brews. It certainly could have had more to do with the malted oats than the Irish moss... .
In a recent brew I did not use Irish moss but did throw in some 15% malted oats. It also has somehow less head retention than what I'm used to.
I read that malted oats can be detrimental to head retention at large percentages, but it shouldn't be a problem at 15 - 20%...
Anyway, for the time being I decided on skipping both the malted oats and the Irish moss, and go back to my older ways. I have been chasing mouthfeel (hence the malted oats), but I also and absolutely want to keep the best head retention I can, as this aspect of beer is very important for me.

Anyway, long story to say that I don't think Irish moss has a perceptible impact on head retention, but I could be wrong.
Thank you for your input. Looks like we are suffering the same fate, experimenting with multiple things at the same time and ending up with an outcome that cannot really be traced back to the definite reason :D

I'm sure that oats decrease head retention, but have no experience at which point it actually happens. I can say that my last batch that included oats didn't have any head at all, but I think this might have been caused by bad yeast, an underpitch can cause this to happen, at least that's what I've read.
 
Thank your input. Looks like we are suffering the same fate, experimenting with multiple things at the same time and ending up with an outcome that cannot really be traced back to the definite reason :D

I'm willing to bet we are not alone with this problem

I'm sure that oats decrease head retention,

Yeah, I also think it is the more likely culprit. I started using malted oats in a NEIPA...no Irish moss and that beer had excellent head retention. That is why at first I did not turn my attention on the malted oats. But probably the huge hop loads including dry hopping of such a beer are helping with head retention as well.
The two beers where I experienced less than ideal head retention had malted oats and were not dry hopped.
 
I'm willing to bet we are not alone with this problem



Yeah, I also think it is the more likely culprit. I started using malted oats in a NEIPA...no Irish moss and that beer had excellent head retention. That is why at first I did not turn my attention on the malted oats. But probably the huge hop loads including dry hopping of such a beer are helping with head retention as well.
The two beers where I experienced less than ideal head retention had malted oats and were not dry hopped.

That would have been my exact thoughts as well.

.....Well.....

My first batch with Irish Moss has been dry hopped with 100g on 18 litres, double my previous dh amount and it has 5% rye malt in it to increase head retention, which I never used before.

But I am sure that a good head will only be caused by the Irish Moss!!!! :ban:
 
That would have been my exact thoughts as well.

.....Well.....

My first batch with Irish Moss has been dry hopped with 100g on 18 litres, double my previous dh amount and it has 5% rye malt in it to increase head retention, which I never used before.

But I am sure that a good head will only be caused from the Irish Moss!!!!


Ah and by the way, even on those two beers the head retention did improve massively with time... it just took more time than normal. Instead of 3-4 weeks, two months to develop a head I deemed acceptable. I still have a few bottles of a saison, it's from one of these two batches: 7 months from bottling right now. It now has a huge, fluffy white head worthy of a saison...Granted, it is a highly carbonated style...this one not nearly as carbonated as a real saison should be, but that obviously helps as well (what were we saying about dealing with multiple variables simoultaneously? :-D). But the point is, during the first two months this beer really did show a fairly poor head retention, despite an already consistent carbonation level.
So yeah, I too believe that something is happening with time and that this something isn't related to carbonation per se.
Keep on the quest! :)
 
Ah and by the way, even on those two beers the head retention did improve massively with time... it just took more time than normal. Instead of 3-4 weeks, two months to develop a head I deemed acceptable. I still have a few bottles of a saison, it's from one of these two batches: 7 months from bottling right now. It now has a huge, fluffy white head worthy of a saison...Granted, it is a highly carbonated style...this one not nearly as carbonated as a real saison should be, but that obviously helps as well (what were we saying about dealing with multiple variables simoultaneously? :-D). But the point is, during the first two months this beer really did show a fairly poor head retention, despite an already consistent carbonation level.
So yeah, I too believe that something is happening with time and that this something isn't related to carbonation per se.
Keep on the quest! :)
For science reasons I shall drink tonight one of my recent English bitters which had disappointing zero head to start with but was now a few weeks undistracted in the bottle, followed by one of my recent batches which is also a saison and had already great head after one week. This beer has 40% spelt flour in it, so no wonder it already expressed good head from the beginning. I'm afraid I'm going to have to use tools to get through the rock hard head after further weeks have passed, but let's see.
 
This beer has 40% spelt flour in it, so no wonder it already expressed good head from the beginning. I'm afraid I'm going to have to use tools to get through the rock hard head after further weeks have passed, but let's see.

How convenient, I was already planning on employing malted spelt instead of malted oats in both my hoppy beers and saisons coming up next!
I was hooked on trying spelt after reading some posts on the main NEIPA thread here on HBT. It apparently contributes to mouthfeel just like oats, with the added advantage of contibuting to head retention as well.
 
In an effort to get rid of chill haze a couple of years ago, I tried an extra large amount of Irish Moss - 2 1/2 tsp in a 5 gallon batch. I did this for 2 or 3 batches. It totally killed the head retention. Apparently, when removing proteins that cause chill haze, some foam positive proteins are also removed. A balance is required.
 
How convenient, I was already planning on employing malted spelt instead of malted oats in both my hoppy beers and saisons coming up next!
I was hooked on trying spelt after reading some posts on the main NEIPA thread here on HBT. It apparently contributes to mouthfeel just like oats, with the added advantage of contibuting to head retention as well.
I can confirm that. I just use Spelt flour, same effect, cheaper and I got it around for baking anyway. Malted spelt should do the same thing, same applies to wheat.
 
In an effort to get rid of chill haze a couple of years ago, I tried an extra large amount of Irish Moss - 2 1/2 tsp in a 5 gallon batch. I did this for 2 or 3 batches. It totally killed the head retention. Apparently, when removing proteins that cause chill haze, some foam positive proteins are also removed. A balance is required.
Thanks for letting us know. That is very good to hear, as I was tempted to do exacty the same experiment :D

Now I won't!
 
It seems like everyone has gone off on this tangent of blaming Irish Moss or other kettle coagulants for lack of head retention. To me it's like the old story of losing your keys here but looking for them under the street lamp because the light is better there.
 
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