Building an air filter; who has tried it?

I use an aquarium pump and stone to aerate wort, with an inline “wheel” air filter. After doing this for years, I’ve managed to get two of those filters plugged in the last two months of brewing. That’s very annoying and could get expensive if it keeps up (nearly 5$ per).

In How To Brew, Palmer has a diagram for a homemade air filter, using “wet cotton” in a tube. Color me doubtful… but then, people use all sorts of methods that pull in contaminated air into the wort, all apparently without a problem: mix-stir, shaking, dropping and pouring, etc. I’ve even read on the Aussie brewing forum about guys using the pump with no filter at all, without a problem. (But hey, that’s the aussies for ya :wink: )

So what the heck. At least with this method, you’re trying to filter some of the bacteria out. I was thinking if the cotton has to be wet, why not use star san too.

Any reports on this method?

And yeah, I know I could go the pure oxygen route, but don’t want any more specialized gear than I already have. My current setup works well, even for big beers; I just hit those a second time 12 - 18 hours later if I think the yeast need it.

IIRC it was suggested to use vodka in that type of cottonball air filter. It’s not for bacteria, just dust particles (that the bacteria would be hitching a ride on) and other miscellaneous crap floating in the air. It’s not sterile or pure but it’s a step up from just using a plain aquarium pump.

Vodka might be a better idea than starsan. I say this because I just built and used one of these, and while it seemed to go ok, a few drops of the liquid do get pushed out of the cotton and into the wort, and vodka is probably better in the wort all things considered. I’m a bit interested in getting the cotton sanitized however, and starsan would seem better for this than vodka in my estimation.

Anyway, it was pretty easy to build. I used the thick-walled pump tubing I already had, two #2 drilled stoppers, and a short section of 7/8 or 1 inch I.D. tubing iirc, and that was it. Looked for sterile cotton balls, but never found any.

I probably wouldn’t do this if I had concerns about the yeast taking off, but I was top-cropping wy 1469 which is an aggressive yeast and I don’t think much is going to compete with these fellers.