Yes, you CAN! The appearance of your finished beer is so important, almost as much as the taste. Sometimes there are just too many floatables, causing a haze. Commercial brewers filter their beer, partially for clarity, but mostly for purification (instead of pasteurization.) Homebrewers usually depend on time to let the particles settle to the bottom of the bottle. Did you know that is why beer bottles are shaped like they are; so the sediment gets caught in the little hollow just below the neck of the bottle as you pour the beer? But that’s another story…
Here is an overview of how to home-filter your homebrew…
First, find an appropriate filter. You can pick up a water filer at one of the big box home improvement centers or your local hardware store. The filter should have an IN connection and an OUT connection. Most people find that the under-sink variety pictured here work well. The most important thing about your filter is the micron size, the smaller the micron rating the smaller the particle it will filter. Here are some tips on micron size… A filter above 4 micron won’t do what you want, it let’s visible particles through. Below 1 micron will likely filter out some of the good stuff, like flavor. I would stick with a 1 to 2 micron filter for best results.
Second, and this is an important one… make sure ALL fermentation is done! The process of filtering will accelerate the aging process. If fermentation is not completely finished, the flavor of the beer will be altered. So keep your beer in fermentation until you are positive (by actual gravity readings) that fermentation is done.
Third, build your filtering system. A homebrew filtering setup consists of a two kegs, a filter, and hoses to connect it all. You want the first keg to have a CO2 IN connection as usual, with the liquid OUT hose leading to the IN connection on the filter. The OUT connection on the filter will lead to the liquid OUT connection on the second keg (less splashing, so less contact with air). You will have to custom build the hoses to connect the kegs to the filter so that they fit your filter connections!
Forth, put your beer into the first keg, the one connected to the CO2.
Fifth, use a low CO2 setting to transfer the beer from the first keg, through the filter, into the second keg. You will have to purge the air from the second keg occasionally. When transfer is complete, set up for your usual conditioning process, either in bottles or in the keg you just transferred the beer into.
Quick Totally Unrelated Tip: You can use this same keg setup (minus the filter in the middle) for transferring soda syrup into pre-carbonated water to speed up the long process of carbonating soda! make sure you connect from liquid OUT post to liquid OUT post, so that the syrup bubbles up through the water.