Build Your Own: Beer Filter/Randall

A Randall? What the heck is that? Randall is short for Randall the Enamel Animal. He is a hop infuser of sorts. Installed between the keg and faucet, he is filled with of lots of whole leaf hops. The beer flows through them on it’s way to your glass, infusing your beer with big hop flavor and aroma. Brilliant! You can see a picture of Randall here on the Dogfish Head site. The other night I was down at one of our local taprooms, Tyler’s, for pint night where they served Dogfish Head 90-minute IPA through Randall, and I decided that I should have a such a magnificent device in my own house.

Coincidentally, I’ve been having some trouble getting a nice clear finished beer in my last couple of batches. It’s mainly a cosmetic thing, but it’s still something I would like to improve. I had given up for a time on using fining agents, but I’m going to give them a try again. I’ve also been trying a less vigorous boil, which I think may be contributing to the problem. So I want to try those things in combination with filtering depending on the style of beer I’m brewing. Since a Randall and a beer filter are pretty much the same thing, this project will kill two birds with one stone.

It’s probably worth noting that a filter like this one is designed to be used with kegged beer and uses CO2 to force the beer through the filter.  While it’s probably possibly to filter via gravity, it would take an exceptionally long time.  Additionally, naturally carbonating the beer (either in the bottle, or keg) will not be possible if you filter out the yeast.

Here is the list of parts for beer filter part this project:

1 – Cartridge style whole house water filter housing.

2 – Bungs to convert the 3/4″ fittings on the housing to 1/4″ beer line sized fittings. You will need to find the appropriate sizes for your filter housing.

2 – 1/4″ Male Threaded to 1/4″ barbed fittings

2 – Liquid side Cornelius Keg Quick Disconnects. I used the MFL type, rather than the barbed.

2 – Barbed to Flare nut fittings. Not needed if you use barbed Quick Disconnects.

10 – Feet of 1/4″ ID beverage tubing

4 – Hose clamps

1 – Filter media. 5, 1 or .5 micron

Additional parts needed to convert the filter to a Randall:

5-6 Additional feet of beverage tubing

1 – Beer faucet, I will use a simple picnic type since Randall will only be out for parties.

1 – Male flare to 1/4″ barbed adapter. My LHBS didn’t carry this part, but MoreBeer has it here.

1 – Stainless steel tube to replace the filter inside the housing. You can use your filter media as a guide to the ID and Length needed. If you can’t find one locally, try McMaster-Carr

I decided to spend the extra couple of dollars on the Flared end keg quick disconnects and adapters so that I could disassemble the hoses for easier cleaning, but you could use the plain barbed ones as well. The end of the tube that mates with the filter housing also has threaded connections. To convert the device from a Beer Filter to a Randall, you will need to be able to remove one of the keg connectors and the threaded connections make this much easier.

Assembly is pretty straightforward. If you assembled your own kegerator this should be no problem at all, but here are a few pictures. Click the thumbnails for full sized pictures.

This is the finished filter assembly with a spun-poly filter media.

A couple of close-ups of the connections.

I used my filter a couple of nights ago with good results. I’ll have some detailed instructions on it’s use up later this week.

Note: I haven’t received the extra parts needed for the Randall yet. When I do I’ll update this next part.

There are 2 additional construction tasks for the Randall parts. You’ll need to assemble the faucet, tubing and barbed adapter from the parts list above. Also, the stainless steel tubing needs to have a series of holes drilled along it’s length. If you look down the center of your filter media you’ll probably notice a similar pattern. This is to ensure the beer flows in the proper direction through the filter housing.

When you’re ready to Randallize your beer, follow these steps to convert the filter.

First, remove the keg quick connect attached to the side of the Filter labeled “Out”. This is where using the threaded Flare end fittings make life easier. Attach your beer line with the faucet in replacing the quick disconnect you just removed.

Next, remove the cartridge housing. Install the drilled stainless steel tube and fill the housing with Whole Leaf hops. Reinstall the cartridge housing back onto the Randall.

Finally, attach the keg connector on the “In” side of the Randall to the beer “Out” on the keg as you would normally.

Step 4, Enjoy!

The beer will foam a bit when it goes through the Randall,. You may find it easier to serve from the faucet into a pitcher and then into glasses when it settles a bit. Your beer won’t be flat, but it can take a little patience to get a full glass.

So there you have it. 2 incredibly useful gadgets in 1. Total cost for this project is around $85 although it could probably be done for less if you use less fittings and try to find the best prices on the internet. Skipping the additional pieces needed for the Randall would reduce the cost by another $15-20.

Check out the the beer filter in action here and Randall doing his thing here.

Tagged as: brewing, filter, gadgets, howto, randall