Filtering Beer

  One of the most common questions we get from the home brewer is; "Can I filter my beer?"

  Of course the answer has always been no, unless you have a draft system or some method of "Artificial" carbonation. The reason most new brewers, particularly those converted from wine making, want to filter their beer is to stop sediment forming in their bottles. Once they realize the consequences of removing the yeast, they usually see the light. Now that we can easily and inexpensively carbonate beer, we can also filter it!

  There are two significant differences between filtering beer and filtering wine. Firstly, as we do not like to use any "additives" with beer, we don’t usually use an anti-oxidant, leaving the beer prone to oxidation during the filtering process. Secondly, as beer contains a relatively high amount of residual sugar, it is prone to foaming when excessively handled, such as during filtering. The trick then, is to use a filtering method where (a) the beer is not excessively exposed to the air, and (b) is not splashed or forced, causing foam up.

  The easiest and most effective way to do this is with a slightly-modified Buon Vino Mini-Jet wine filter. The beer needs to be filtered into a closed carboy that has been purged of air either with CO2 or Corked Again. Just spray enough in to form a blanket of gas on the bottom of the carboy. Then you need to seal the carboy with an orange carboy cap. This has two holes in it. Put an airlock in one hole (half filled with water, of course), and put a racking tube in the other hole, pushing it all the way through so that it is about 1/4 of an inch off the bottom of the carboy. Now connect the outflow from the Mini-Jet to the racking tube and filter as normal. The idea here is that by feeding the filtered beer in to the bottom of carboy foaming will be kept to an absolute minimum, and by putting in a blanket of inert gas the beer will be protected from over-exposure to the air.

Be sure to only use coarse filter pads!