[Eldritch Brewer]

Hello all,

I'm looking for some advice regarding filtration. I have a re-purposed water filter that I use (see image) to clarify my beers, typically through a 1 micron filter. I've got several lagers aging right now, and I'm wondering if filtering the beer would help them lager faster? My understanding of aging is that larger compounds break down, and fermentation flavors mellow and dissipate. By filtering and removing the yeast, will I stop that process from happening? By filtering, can I remove those larger compounds and simply reduce the need to age for such lengthy periods?

On a similar note, how much flavor will I lose by filtering? I've heard advice--typically strongly stated--from both sides on this. Some say that filtering strips flavor, and some say that the loss is negligible. In my limited experience, the flavor loss does not seem very substantial, and I really appreciate the clean, clear, results. I do not typically brew hoppy beers, and instead go for stouts, scotch ales, ciders, and--increasingly--lagers (Marzens, Pilsners, and Bocks). What is the effect of filtration on beers like these?

If you would be good enough to explain your answers, I'd really appreciate it. I want to really understand this, so please be as thorough as possible. One line answers aren't very helpful.

Thank you so much for your time, I look forward to hearing what you have to say!

[Robert]

One of they key ways flavor mellows is simply by the removal of yeast, with its own flavor and that of hop resins that adhere to it. The key is that yeast needs to have completed fermentation and metabolization of byproducts like diacetyl, which it does toward the end of fermentation.

At that point yeast has nothing more to do, and you're on to physical processes.  Crash cooling the beer for a couple of days will start settling yeast, and also form chill haze.  Now  you can either filter the beer, fine the beer and wait a while for precipitation of yeast and chill haze particles,  or just keep it cold and wait even longer for precipitation. Filtration doesn't speed up lagering, rather it replaces lagering to remove suspended solids.

If you like filtered beer, there's no reason for longer cold storage after the yeast is done and before filtering. 

The typical method for lagers is to raise the temperature to 60°F or higher toward the end of fermentation to hasten the completion of fermentation, holding the beer warm until the yeast starts to settle on its own (showing it is no longer active.)  If you dropped the temperature before fermentation was complete, just make sure you have in fact reached FG.  In that case the yeast has also finished its work.  Then you can go ahead and filter, carbonate and enjoy as soon as you like.  As I say, once the beer is done, it's not ageing, just getting old.  Filtration is one way to get it to your glass as fresh as possible.

I am one of those who has filtered for many years, but am getting away from it because I think it strips some flavor and body.  But opinion is divided and a matter of personal preference.  If you filter, take advantage of the time you can save!