How Long Can You Keep A Half Empty Keg?

[Steve@PMF82]

"Filtered beer tends to have a relatively short shelf life, rarely more than a year, as many compounds in the sterile beverage break down into unpleasant tasting ones. Live yeast inside the bottle acts against these processes, giving the beverage a much longer shelf life. A good bottle conditioned beer can maintain its drinkability for many years, and some can be aged for decades."

http://en.m.wikipedia.org/wiki/Bottle_conditioning

Most home brewers filter their beer with a 1 micron absolute or nominal filter, definitely not sterile. Still enough yeast to bottle condition, depending on your yeast handling and cold side practice.

 

[Steve@PMF82]

Still looking into Polyclar, but is it considered a preservative or just another fining agent?

Its neither, it is a inert stabilizing agent, stops polyphenol protein complexes forming. If you filter after it is no longer in the beer.
Same can also be achieved by letting it settle out over a few days then racking from the top.

 

[Nick JD]

"Filtered beer tends to have a relatively short shelf life, rarely more than a year, as many compounds in the sterile beverage break down into unpleasant tasting ones. Live yeast inside the bottle acts against these processes, giving the beverage a much longer shelf life. A good bottle conditioned beer can maintain its drinkability for many years, and some can be aged for decades."

http://en.m.wikipedia.org/wiki/Bottle_conditioning

Yeah - not sure I agree with that. Filtered beer is not "sterile". Did they mean "pasteurised"?

Taking out the polyphenols and the yeast will give it a longer shelf life. Kinda why all the beers in the bottlo are.