Build A Kegerator Hop Filter: Add more flavor to your beer

Most of the home brewers I know that own kegerators rarely bottle their homebrew anymore. Kegging is just simply an easier way of fermenting, conditioning and dispensing. But some of the most hopped homebrews I've tasted lately seem to come in bottle form. So being one of these kegerator home brewers, I have to ask myself "How can I make my draft homebrew hoppier?"

Kegerator-Hop Filter
Adding a hop filter to your kegerator system will intensify your brew's flavor.

A good number of the local homebrew clubbers I run with use secondary and even tertiary fermentation techniques along with extreme amounts of whole hop flowers and hop oil extracts to achieve their bottled hop flavor/aroma profiles. I use kegs as my secondary and tertiary fermenting vessels when brewing, and with the right timing, this allows my brew to self-carbonate with the malt sugars left over from the main fermentation.

With this process of fermenting, conditioning and dispensing within a closed keg system there never seems to be a good opportunity to introduce any additional bittering/flavoring/hop aroma to my draft homebrew, so filtering my brew within the system seems like the answer.

I had read about the elusive Randall the Enamel Animal, a Dogfish Head invention, and many other different types of hop filter builds online and from friends, but I wanted to build a hop filter that was going to be kegerator-friendly, easy to detach and clean and cost effective. So it was settled. I decided to introduce a hop filter to my home kegerator system.

The only thing I knew for sure I would need was a water filter housing, so off to the hardware store I went. I browsed a few different models and eventually chose a water filter with ¾" female pipe threads and a 3-position bypass valve so the hop filter could be changed without detaching from the keg. I knew I had a plethora of fittings, bushings and couplers lying around my garage as well as tubing and O-rings, so my next stop was the homebrew shop.

After talking with a few of the veteran home brewers at the shop I quickly realized that there was going to be a million different ways to build this hop filter, so I had to determine what the key functionality needed to be. Hop flavor injection capability was obviously important and bypassing and ease of cleaning came to mind.

After staring at the bevy of inventory for a good half hour, I started grabbing parts. Quick disconnects on the filter housing would let me detach the entire filter unit from the kegerator dispensing system for easy cleaning. The kettle screen, usually an accessory that turns your brewpot into a mash tun, would be easier to modify into a filter than buying a stainless steel rod and drilling holes.

After assembling the hop filter, getting it installed and pouring my first homebrew (Black Rye), I have to say I could really taste a difference in the hop profile of the beer. One small addition to the kegerator has made an already smooth operator into a smooth hoperator!

Parts and equipment list
• GE Household Pre-Filtration System - Model # GXWH20S
• Brewer's Edge® KettleScreen™ with ½" thread and 12" long
• ½" Male pipe thread to ⅜" male barb connector
• 4 small ⅜" O-rings
• 3 clamps
• ½" female pipe thread to ½" female pipe thread coupling
• 2 Firestone liquid posts with ⅜" female pipe thread
• 2 ⅜" Male pipe thread to ½" male pipe thread reducers
• 2 ¾" Male pipe thread to ½" female pipe thread bushings
• 2 Quick disconnect fittings for ball lock kegs with ¼" MFL (threaded)
• 2 ¼" swivel nut to ¼" barbed end sets
• 4 ft. of 3/16" inner dimension PVC tubing
• Teflon tape
• Filter wrench
• Adjustable wrench
• Flat head screwdriver
• Metal snips
• Measuring tape
• Bolt cutters
Gather Your Supplies

I have a mountain of spare homebrew parts scattered around my home, as most home brewers I know do, and was able to track down most of the fittings including the clamp, coupler, reducers and bushings. Before I got started on assembly I needed to take inventory of my tools and supplies to make sure I could finish what I started and low and behold I was missing a vital piece that sent me back to the homebrew shop. I had overlooked getting a second quick disconnect fitting to connect the "out" on the hop filter to the "in" on my tap tower. It's always a good rule of thumb to lay down the game plan before you get started with any project. When I returned home my good buddy Brew (my Golden Retriever) had taken it upon himself to play tug-o-war with the beer line I had purchased to connect the hop filter and tap tower together. So yep, you guessed it, back in the car and back to the homebrew shop. This time I bought a bushel of beer line.


Before you get started assembling the fittings for the quick disconnects, make sure to clean all of the parts with sanitizer. You will need to lay out the three parts (¾" Male pipe thread to ½" female pipe thread bushings, ⅜" Male pipe thread to ½" male pipe thread reducers, Firestone liquid posts with ⅜" female pipe thread) for each side and wrap the male threads of each fitting with the Teflon tape. (Note: In this project I am using a mixture of brass and stainless steel fittings. It is recommended that you use all stainless steel fittings when possible, but I had these parts already. ) After you get all of the fittings tightly screwed together you can insert the ¾" Male pipe thread of the bushing into the ¾" female pipe thread on the filter housing. Repeat this on the other side of the filter housing and you will have successfully assembled the quick disconnect liquid posts for use with the quick disconnect fittings for ball lock kegs.


Measure 7" up from the crimped end of the Brewer's Edge® KettleScreen™ and cut with your metal snips. Make sure to reshape the sniped tube back to its original shape with a pair of pliers. On the half with the threaded fitting use your bolt cutters to cut off the permanent clamp and remove the fitting. Remove the ½" threaded fitting and insert it into the end of your newly cut 7" screen. Slip on a stainless steel adjustable clamp and tighten. Next, screw on your ½" x ½" female pipe thread coupling and then screw in the ½" x ⅜" male barb connector into that. Slip on the 4 small ⅜" O-rings until they about midway down the barb. When you have completed these steps you should have something that looks like the modified screen in the picture.


This step is actually very simple and it is designed to be. Slowly twist the screen assembly into the opening on the inside of the filter assembly cap. The O-rings you used on your barb fitting should twist in and be quite snug. The purpose of this design is for making cleaning of the hop filter as easy as possible. When ready to clean the filter you will just slowly twist out the filter assembly from the filter cap. During dispensing the PSI in the filter housing will force the screen up and create a natural pressure seal. These filters are designed to withstand up to 125 PSI, so you do not have to worry about its pressure capability because most beers are dispensed between 5 and 12 PSI. Note: Make sure you tightly secure the clear filter closure to the filter cap with the included filter wrench.


Once the filter is assembled we will now be ready to attach it to the rest of the kegerator dispensing system right? Wrong. Make sure you clean, clean, clean this filter. The last thing needed at this point is for your beer to be contaminated by an unclean "filter". Use regular brewing sanitizer and baptize your new hop filter. After you have cleaned you are ready to add the filter to the system. The beer should flow from you keg like this: KEG » HOP FILTER » TAP TOWER. Assemble your beer line jumper out of the two quick disconnect fittings, ¼" swivel nut x ¼" barbs, clamps and the PVC beer line. Connect the beer line jumper from the keg's beer line "out" to the hop filter's line "in" liquid post. Then connect the tap tower quick disconnect to the hop filter's line "out" liquid post. You now have completed the connection and have another important step at this point. What kind of hops to use?

Test Drive

I chose to use Centennial whole leaf hops for the first run through the filter. My homebrew on tap at the time was a Black Rye brewed with Columbus and Centennial and then dry hopped with Amarillo and Centennial. I turned on the CO2 and set it to around 8 PSI and watched the hop filter fill with beer. As the beer traveled down and then back up through the screen I watched for leaks around all of my fittings. Success! No leaks and the beer made it all the way out and up to the tap tower dispenser. At this point I closed the kegerator door and let the temperature come back down to 38 degrees before dispensing to minimize foaming. Upon pouring my first beer I could hear the hiss of the beer flowing through the filter and it made me feel good. The beer was foamy, but quickly settles and I could see some particulate had made its way through the filter. After a few beers the particulate matter cleared and I was left with a noticeably hoppier brew.

Christian Lavender is a homebrewer in Austin, TX and founder of and

Related Kegerator Projects :
Adding Chalkboard or Whiteboard Surfaces to your Kegerator -- Adding a chalkboard or a whiteboard to the outside of your kegerator is a useful project
Adding Taps to Your Kegerator -- Adding taps to your home draft system, or kegerator , is easy.
Beer Keg to Kettle Conversion -- Part 1 of's tutorial video on how to turn a beer keg into a 15 gallon brewing kettle.