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General Category => Yeast and Fermentation => Topic started by: Kaiser on October 19, 2012, 02:29:41 PM

Title: Foam stability and oxidation
Post by: Kaiser on October 19, 2012, 02:29:41 PM
I don't always point to my blog articles here but I made an interesting observation last night:

(http://braukaiser.com/blog/wp-content/uploads/2012/10/Batch_127-2.jpg)

The beer on the left, the one with the coarse bubbles was bottled w/o O2 and the one on the right was. The difference in foam stability is astounding. But I have to admit that this was only one bottle against another one. It's likely that the O2 didn't cause this difference and I have to see how other bottles of this beer pour.

http://braukaiser.com/blog/blog/2012/10/18/better-foamstability-through-oxidation/

I don't think many are playing with intentional beer oxidation, but I think brewers should. I know Fred noticed better aging through oxidation. Maybe O2 at bottling time can become a respected technique even though it flies in the face of conventional brewing wisdom.

Kai
Title: Re: Foam stability and oxidation
Post by: morticaixavier on October 19, 2012, 02:49:46 PM
That's a great experiment Kai.

I am getting ready to bottle the rest of a keg of old ale and I don't really have a way to purge the bottles with co2. given your results I won't worry about that so much. I don't have a way to purge the headspace with pure o2 either but that's okay.
Title: Re: Foam stability and oxidation
Post by: Kaiser on October 19, 2012, 02:51:29 PM
what you could do is remove the foam from the head space or leave a large enough head space that there is air in the bottle. Then compare a few months later.
Title: Re: Foam stability and oxidation
Post by: morticaixavier on October 19, 2012, 02:54:31 PM
what you could do is remove the foam from the head space or leave a large enough head space that there is air in the bottle. Then compare a few months later.

I'll give that a try. I have been filling the bottles to within about .5-.75 inches from the top and capping on foam per 'common wisdom' so when I bottle this up i'll repeat your experiment... sort of. I'll do have the bottles the 'normal' way and half your way. If I have an empty keg I can use to run co2 through I will split it three ways. tiny headspace with air, bigger headspace with air and control with co2 purged bottles.
Title: Re: Foam stability and oxidation
Post by: Kaiser on October 19, 2012, 03:06:02 PM
If you have some yeast around, you may also want to add yeast to some bottles. I'm always looking for repeats of the experiments I'm doing :)

Kai
Title: Re: Foam stability and oxidation
Post by: morticaixavier on October 19, 2012, 03:06:26 PM
If you have some yeast around, you may also want to add yeast to some bottles. I'm always looking for repeats of the experiments I'm doing :)

Kai

I'll see what I can do!
Title: Re: Foam stability and oxidation
Post by: hopfenundmalz on October 19, 2012, 04:41:30 PM
Kai - were both glasses beer clean? The one on the right has bubbles on the glass below the surface of the beer.
Title: Re: Foam stability and oxidation
Post by: Kaiser on October 19, 2012, 05:47:11 PM
Jeff,

Good point and I did think about this. There were lots more bubbles on the glass of the non-O2 beer which could be related nucleation sites like lime scale. But I also noticed the foam instability in the other glass that I used for this beer. But making sure the glasses had the exact same cleanliness for each beers was something I did not pay attention to at the time. I will make sure of this next time I compare samples. This means soaking in diluted vinegar, cleaning with soap and rinsing with RO water. Since this is a lot more work I only do that when I want to take “pretty” pictures of beers.

In general I don’t see much effect of the glass on foam stability. As mentioned in the post I regularly asses foam stability and rarely worry about special cleaning of the glasses. I wash all these glasses in the dishwasher. In the vast majority of cases the foam is pretty stable (7+ min). I know that there was no oil in or on the glass, though.

Kai
Title: Re: Foam stability and oxidation
Post by: hopfenundmalz on October 19, 2012, 07:05:11 PM
Jeff,

Good point and I did think about this. There were lots more bubbles on the glass of the non-O2 beer which could be related nucleation sites like lime scale. But I also noticed the foam instability in the other glass that I used for this beer. But making sure the glasses had the exact same cleanliness for each beers was something I did not pay attention to at the time. I will make sure of this next time I compare samples. This means soaking in diluted vinegar, cleaning with soap and rinsing with RO water. Since this is a lot more work I only do that when I want to take “pretty” pictures of beers.

In general I don’t see much effect of the glass on foam stability. As mentioned in the post I regularly asses foam stability and rarely worry about special cleaning of the glasses. I wash all these glasses in the dishwasher. In the vast majority of cases the foam is pretty stable (7+ min). I know that there was no oil in or on the glass, though.

Kai

Thanks, had to ask the question. I sometimes pull a glass from the cabinet that ends up looking like the one on the left, probably due to dust.
Title: Re: Foam stability and oxidation
Post by: jeffy on October 19, 2012, 08:08:53 PM
The one on the left looks just like Ray Daniel's "example of a glass that's not clean" photo.
Title: Re: Foam stability and oxidation
Post by: seajellie on October 19, 2012, 08:58:38 PM
In regard to Kai's comment about "better ageing with oxidation," I just did a blind triangle test with a friend and two big beers. One was a Baltic Porter (w/ lager yeast) and the other was a Belgian Dark Strong (w/ Chimay yeast); one sample of each had sat in the cellar at around 60 - 65 for six months, and the other sample had been in a fridge at 42 - 45 for that same time.

I remember that there was a difference in appearance and in the bubbles, can't remember about foam stabillity, but I have no photos to share anyway. The big thing was the taste; both of us correctly differentiated and matched both brews. I found it amusing that he preferred the refrigerated samples; I greatly preferred the cellared samples. I found the cellared examples to have somewhat sherry-like or liquor like complexity that works well with a lot of darker brews.

I've long suspected that I like a bit of oxidized ageing to the big brews, and have the proof now!
Title: Re: Foam stability and oxidation
Post by: Thirsty_Monk on October 21, 2012, 12:42:01 AM
Foam stability is somewhat to interest to me.
From beer presentation point of view.

I have a small BK and I had a boil over quite often.
I discover that beers without boil-over had better foam stability then beers with boil-over.
It goes down to soluble and non soluble proteins.
So do not skim the protein from BK and do not have boil-over.
Title: Re: Foam stability and oxidation
Post by: denny on October 21, 2012, 05:30:35 PM
Re: glass cleaning....I've been doing a salt scrub recently when I want sparkly clean glasses.  Get the glass slightly damp, sprinkle salt all over the surface, rub with a paper towel and rinse.  Makes a noticeable difference in beer foam.
Title: Re: Foam stability and oxidation
Post by: mabrungard on October 21, 2012, 06:12:09 PM
In regard to Kai's comment about "better ageing with oxidation," I just did a blind triangle test with a friend and two big beers. One was a Baltic Porter (w/ lager yeast) and the other was a Belgian Dark Strong (w/ Chimay yeast); one sample of each had sat in the cellar at around 60 - 65 for six months, and the other sample had been in a fridge at 42 - 45 for that same time.

I remember that there was a difference in appearance and in the bubbles, can't remember about foam stabillity, but I have no photos to share anyway. The big thing was the taste; both of us correctly differentiated and matched both brews. I found it amusing that he preferred the refrigerated samples; I greatly preferred the cellared samples. I found the cellared examples to have somewhat sherry-like or liquor like complexity that works well with a lot of darker brews.

I've long suspected that I like a bit of oxidized ageing to the big brews, and have the proof now!

I think the primary thing you were witnessing was the accelerating effect of temperature on oxidation.  It certainly can be a good thing in some cases.  Not so good in others.