Ok your claim is that transferring lets say 7 litres of wort from kettle to mash tun would result in a greater dissolved oxygen of 1ppm. Ok I can dig that.
As for oxygen and its effect on the coagulation of polyphenols during the hotbreak and the subsequent knock on effect elsewhere, thats a much more bitter pil to swallow.
Whether we have had these issues or not does not negate the scientific facts that oxidation of polyphenols in the mash helps them to bind to proteins and precipitate out of solution. A process which your methodology will inhibit. Can you understand why this excess protein and polyphenol load could be passed onto the cold side rather ironically resulting in an INCREASE of the risk of oxidative flavours that you were seeking at all turns to avoid?
The danger is that we simply cherry pick elements from scientific literature and ignore what we don't want to hear because it conflicts with our methodology.
You are misunderstanding what I am saying. I'm not trying to negate, or sweep under the rug any hard brewing science facts.
There a many ways, all process based, that you could leave these rather undesirable contents behind. A good indicator that you have is pre-boil wort clarity. The use of a brew bag as a pseudo-mash filter is a very good technique. Combined with recirculation and mashing regimen that ensures full conversion, and you have a recipe for nearly crystal clear wort going into the kettle. From Kunze:
"...polyphenols, long-chained fatty acids in particular play a significant role, especially with regard to the flavour stability of the
beer. In comparable tests on a turbid (140 EBC) and clear (16 EBC) wort, it was shown [399) that the proportion of long-chained fatty acids and oxidised lipoxydoxidation products, such as hexanal, pentanal and nonalacton increase disproportionately in the turbid wort."
So, I understand what you are trying to say, but oxidation of polyphenols is not the single source answer to their removal from further stages in the process.
In fact, it can be argued, and supported from text, that oxidizing polyphenols has a negative effect. From Kunze:
"The use of malts rich in polyphenols provides protection from oxidation in the brewhouse and improves the anti-oxidative potential of the wort
and of the beer. This means that oxygen ingress has to be prevented from the beginning."
Also from Kunze:
"The polyphenols have an anti-oxidising effect and thus have a positive influence on the flavour stability of the beer. The protection against oxidation provided by the polyphenols thereby supplements the protection provided by sulphite. An increased polyphenol content should thus be aimed for during mashing, whilst at all costs avoiding the access of oxygen."
I don't want to give the impression that I have an agenda. We don't gain anything from what we put out. And the "methodology" you reference is culled from the pages of Kunze, Narziss, Fix, DeClerck, etc, i.e. it's not original to us.
Just because I don't expound on a simple answer on a forum doesn't mean i'm trying to negate science. It's quite the opposite. We are trying to
promote hard brewing science.
I'm also not looking for conflict, argument, etc. I'm just presenting what I know or have seen empirically with some backup from my favorite brewing science textbooks. I'm just interested in an honest dialogue about these subjects!
