How to use your new Beer Filter

Now that you’ve assembled your Beer Filter you’re probably interested in some instructions on using it. Before we begin though, there are a couple of things to keep in mind.

- Sanitize the filter before you run beer through it. To accomplish this, I use the same process outlined below for filtering beer, substituting the keg of beer I want to filter with keg of StarSan solution.

- You want to filter your beer before it is carbonated. The filter will strip out the carbonation so you’ll be stuck having to re carbonate the beer again if you don’t.

- Don’t filter the beer if you intend to carbonate it naturally. Depending on the filtration level of the media, you may remove all of the yeast which will prevent the beer from carbonating later (unless you want to carbonate via krausening, but that’s another topic).

- Filter Cold. You know that commercial on TV? The one where the guy with the tough cowboy-on-the-range voice talks about how their beer is “Cold Filtered for that Rocky Mountain taste” (or something like that)? Yeah, everyone does that. Chilling the beer causes the compounds responsible for chill haze (imagine that) to come together, making them easier to catch in the filter.

- Be sure you have emptied the sanitizer from the keg that will receive the beer. You don’t want to be that guy (or girl) who racked his (or her!) freshly filtered beer into a keg full of sanitizer.

Also, a quick note on choosing filter media. Typically you will find 3 levels of filtration; .5, 1 and 5 micron. 5 micron is a rough filter, good for removing large particles and some minor haze. Use 1 micron if you want to approach the clarity level you might find in a commercial beer. The .5 micron is close to sterile filtration, could potentially remove some flavor components and can reduce the shelf life as well. The media also comes in 2 types; absolute and nominal. Absolute filters are generally quite a bit more expensive, and as the name implies will filter absolutely everything at the rated filtration level. Nominal filters may not catch quite everything at their rated level.

When you’re ready to filter, follow these steps.

1. Use a gas line from your CO2 tank to purge the oxygen from the receiving keg.

2. The Filter is designed to flow in one direction and should be labelled “In” and “Out”

2a. Connect the “In” side of the filter to the beer “Out” side on the keg of beer to be filtered.

2b. Connect the “Out’” side of the filter to the “Out” side of the empty receiving keg.

3. Attach the gas line to the gas “In” on the keg of beer to be filtered.

4. Start the flow of CO2. Begin with the regulator set at about 2-3psi and increase it if all seems to be going well.

5. Open the pressure relief valve on the receiving keg.

Here’s an illustration of the connections and direction of flow. This is one of those times when a picture makes it much easier to understand the process.

Depending on the level of filtration and the amount of material it collects, the filter can become clogged. Try a little more CO2 pressure, but if the filter media becomes too clogged you’ll probably need to back flush it. If you are filtering with a reusable media you will also need to back flush it with clean water when you are done filtering the beer. In either of these cases, simply reverse the filter connections (Out becomes In) and run the liquid through the filter in the “wrong” direction. To clean the media after filtration I use the keg of StarSan again to back flush. Drain the excess StarSan solution from the media and store it in the freezer to prevent contamination.

Another illustration with the flow reversed to back flush.

So there you have it. If all went well, you now have one more tool available to you in the quest to brew the perfect pint.

Tagged as: brewing, filter, gadgets, howto