Ever since I began brewing beer I’d heard about filtering my beer to remove haze. While I know that filtering is not necessary as with sufficient skill one can produce quite clear beer without it, it held some appeal to me. After learning that a number of local breweries filter their beer to remove haze and produce sparkling, shiny, clear beers that still have quite a bit of flavor I became even more interested, so after cleaning the beer lines and getting some more stuff kegged I decided to order the parts to give it a go.
To get started I tried filtering a rye pale ale that I brewed a few months ago and kegged just after cleaning the lines. It was already partially carbonated so it foamed a bit during the process (nucleation in the filter and due to pressure drop), but there it wasn’t nearly as much of a problem as I’d expected. I used a 5 micron filter for this batch (the 1 micron filters hadn’t come in yet), and this left the beer a every so slightly hazy, but it looks way better than it had with just aging and letting settle in the keg and it still tastes great.
The process I put together (based on lots of info I’d read) uses a Pentek 158116 filter housing with two liquid-out ball lock keg fittings connected to each side. The housing is sanitized then fitted with a filter that has been dipped in sanitizer, the filter is fitted between two kegs (full keg on the in side, empty on the out), the empty keg’s safety valve is opened, and CO2 is applied to the full keg to push the beer through. I started out with 2-3 psi, but near the end I had to increase this to around 10 psi as the filter became clogged. Periodically throughout the process I’d open the top of the output keg to check the level and foamyness, closing it back up to keep the system relatively closed.
This worked out very well, and I only had a bit of foam blow out through the safety valve right near the end of the process. This lost foam likely resulted in a loss of only a couple ounces of beer, and the filter housing itself probably lost half a pint.
Next time I try this I’ll chill (but not carbonate) the beer in a keg, then force it through the filter to another. I expect that there’ll be no foaming then resulting in even less hassle and mess. The next time I try this will be with the two beers I’ve got brewing now (a golden ale and a red ale), perhaps with 1 micron filters if they arrive in time. My desire is to get crystal clear, sparkling beers that still have good flavor in a relatively short period of time, just by filtering it.
Here’s a few photos taken during this filtering experiment:
· Two kegs, Pentek 158116 filter housing, 5 micron water filter, and connections necessary to filter beer.
· Mostly-carbonated rye pale ale being filtered.
· Since the beer was already carbonated it foamed a little out of the pressure release, but not enough to cause problems. There was very little loss overall.
· Side view of the filter after processing five gallons of beer.
· End view of the filter, from the top, after processing five gallons of beer.