Messages

1

General Homebrew Discussion / Re: cold side aeration and staling reactions

« on: December 14, 2009, 08:27:10 AM »

Thanks Kai,

I am new to the forum, but am not a new brewer.  This is more of a theoretical discussion than a practical one.  I'm not at all worried about oxygenating before pitching, and agree that it is the easiest way to provide yeast some of the nutrients they need.  This topic came up during a conversation with another brewer over the weekend.  I suspect that aeration at any point in the process is bad for beer, but adding yeast soon after aeration protects it from the oxidation that would otherwise be detrimental. 

2

General Homebrew Discussion / Re: cold side aeration and staling reactions

« on: December 14, 2009, 07:26:59 AM »

I am not aware of any staling issues with aerating/oxygenation at pitching temps.

I do  not have a specific reference, but if this is true why are we so careful to avoid excess splashing when transferring beer?  Some even advocate transferring under a CO2 blanket to avoid oxidization and staling. 

3

General Homebrew Discussion / cold side aeration and staling reactions

« on: December 13, 2009, 10:03:12 AM »

Could someone explain, or point me to some info on cold side aeration and it's effect on decreased shelf life, or staling reactions?  I'm not 100%, but I suspect that there would be a difference if you take some cool wort, aerate it, then divide it into two containers.  The 1st container is pitched immediately with the appropriate amount of yeast, the other container is pitched several days later, (3-7 days)

In the 1st container the yeast would scavenge all the O2 they need right away, while in the second container the 02 would be free to react with various wort compounds and decrease the shelf life and increase the staling of the finished beer.  This is of course assuming that your sanitization practices are perfect.  I'm not interested in hearing about problems related contamination issues.

Which compounds are responsible for staling/oxidization reactions?
Is my thinking correct?