Hot Side Aeration
Moderator: Jimmy Orkin
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Thors Brother
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- Joined: Mon Aug 31, 2009 8:31 am
Hot Side Aeration
Does anyone know if Hot Side Aeration (HSA) causes cloudy beers? Is cloudiness even related to HSA?
Re: Hot Side Aeration
The mechanism of haze formation is the following: Haze active proteins contain a number of active sites, thought to be the proline residues, which have a specific affinity for polyphenols. If polyphenols have two binding ends, they are capable of linking protein molecules together, forming colloidal particles, which create haze.
Smaller colloidal particles initially form in beer, as there are insufficient amounts of polyphenols to link any more than two protein molecules together, hence light hazes form. Larger particles and increased haze can form when polyphenol levels approach those of the protein (due to oxidative reactions during storage ), as polyphenol linking of the proteins can form large networks.
So, understand that Oxidative reactions can contribute to the polyphenol linking of the proteins, I would have to say that if HSA is significant enough to bond O2 to the malt then it could definately contribute to this oxidative reaction.
Now, this being said I must say that I know brewers who don't worry at all about HSA and make excellent beer. So I can't tell you for sure that HSA alone causes haze but if the conditions are right where protien levels and polyphenol levels approximate the same levels, it can contribute to the formation of haze.
Smaller colloidal particles initially form in beer, as there are insufficient amounts of polyphenols to link any more than two protein molecules together, hence light hazes form. Larger particles and increased haze can form when polyphenol levels approach those of the protein (due to oxidative reactions during storage ), as polyphenol linking of the proteins can form large networks.
So, understand that Oxidative reactions can contribute to the polyphenol linking of the proteins, I would have to say that if HSA is significant enough to bond O2 to the malt then it could definately contribute to this oxidative reaction.
Now, this being said I must say that I know brewers who don't worry at all about HSA and make excellent beer. So I can't tell you for sure that HSA alone causes haze but if the conditions are right where protien levels and polyphenol levels approximate the same levels, it can contribute to the formation of haze.
Scott Townson
May judges be smitten with our brews and long for our nectars throughout eternity!!
May judges be smitten with our brews and long for our nectars throughout eternity!!
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Thors Brother
- Posts: 50
- Joined: Mon Aug 31, 2009 8:31 am
Re: Hot Side Aeration
This is a lot to digest. I read it 5 times and I still am trying to grasp it. It leads me to more questions, but I will try to read more about brewing fundamentals before asking any additional questions for now. Do you have any books or references on brewing fundamentals to help me better understand? Something more in depth than Papazian's book? Thanks.
Re: Hot Side Aeration
Scott Townson
May judges be smitten with our brews and long for our nectars throughout eternity!!
May judges be smitten with our brews and long for our nectars throughout eternity!!
Re: Hot Side Aeration
Scott Townson
May judges be smitten with our brews and long for our nectars throughout eternity!!
May judges be smitten with our brews and long for our nectars throughout eternity!!
Re: Hot Side Aeration
Thors, that pretty much explains all there is to know about Beer Haze. So dig in!
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Thors Brother
- Posts: 50
- Joined: Mon Aug 31, 2009 8:31 am
Re: Hot Side Aeration
This is awesome!! Thank you very much!