Filtered v. Unfiltered beers.  Brewer Mike Memsic discussed the ways that filtering affects the flavor and style of craft beer. 

I’ve been attending these Beer Appreciation Classes pretty regularly.  Originally they were promoting that you’d get an MBA – Master of Beer Answers!  Pretty cool.  The classes are held on a Monday near the first of the month.  It’s a great chance to discuss brewing with commercial brewers – for example David Zuckerman discussed dry hopping and all things hoppy.  A class was taught on cask conditioned ales.  Steve Trese discussed yeast.  It’s a great reason to get out and have a drink – and learn something!

The class on filtered v. unfiltered was exceptional.  I’ve been thinking about getting a plate filter since my last dopplebock.  I didn’t pull the hot break from the boil kettle – what was I thinking? So I ended up with a persistent funky foam in EVERY glass of beer.  The main goal of filtering beer is to improve shelf life.  Reasons not to include yeast being a characteristic of the beer style (hefeweizen for example) or having bottle conditioned ales.  Mike discussed how you might want to control the amount of yeast in your product for consistency from batch to batch, so you would filter to certain level.

We also discussed finings including isinglass (the swim bladder of a sturgeon – watch out vegans) and gelatin.  I asked about Irish Moss, which I guess isn’t really a fining.  My dumb question of the night.  🙂

We toured the brewery and saw Peter setting up the 10M DE filter (DE = diatomaceous earth, or porous shells from diatoms).   It was cool seeing him make the beer slurry that would be used to coat the filter screens.  He looked like he’d been working with flour – his entire face was coated with powder.

They were getting ready to filter a very hoppy beer (Single Track?)… we got to see a pitcher of the unfiltered beer.  It was  illegal to taste it because of regulations from the revenuers (TTB – Alcohol and Tobacco Tax and Trade Bureau.)  It looked and smelled just like hop milk though. Yum.  Then we tried some of the filtered beer from the bar.  Even the most casual observer would have seen THAT difference!

We also got to hang out at the plate and frame filter and oh-and-ah over that.  It must be some serious work running a brewery.  These things have to be back flushed daily, repaired and replaced every week.  In the end, it’s worth it, because you get great beer!