Electromechanical kegerator

[BryskeBrynolf]

Hi folks! Long time lurker on this exquisite board just wants to share this humble low-tech construction of mine.

Two years ago when I was decieved into homebrewing, I had no ambition to become any kind of equipment or DIY nerd. I felt quite content with stove-top BIAB and carbonating in bottles.

Before long, however, I found myself owning a 60 liter brewing system, four Cornelius kegs, a used fridge and a 5 kg CO2 cylinder. Armed with a drill, some JG couplings, tubes and picnic taps I soon was the proud owner an adequate kegerator.

Somehow, however, I was craving more. Having drooled for some time over the shiny Perlick taps I got hold of a 650SS and realized I didn't really have room (or funds) for three more. And besides, I would rarely need to tap more than one beer at the time. Here's the solution I came up with:

Basic requirement specification:

• All four beers must be served through the same single Perlick tap
• Minimize tubing
• Minimize cost
• No digital electronics
• Robust operation and maintenance

Solution:

Front. Indicator LEDs in the holes where the picnic taps used to be. Soap tray not ideal.

Inside of door. Yes, it needs a finishing cosmetic touch.

Inside of fridge. The cut up Category 5 TP cable is as digital as it gets. Fourth keg on bottom shelf.

The beer hub. All 3/16”.

Tacky wiring diagram. Valves at bottom right.


Components:

• 1/4” Electric Solenoid Valves 12V DC
• John Guest 3/16” T
• John Guest 3/8" - 1/4" BSP and silicon thread seal tape
• John Guest Reducer 3/8" – 3/16"
• 12V DC Power Plug Adapter Connectors Male & Female
• Rotary switch with chicken head knob
• 12V LED lights
• 12V DC Power adapter, 1A
• Assorted cables
• 3/16” tubes
• Terminal blocks

Features:

• Affordable
• Distinct operation
• Valves just tight enough to constrict flow, making extra length of 3/16” tubes unnecessary. An unexpected advantage.
• Easy connect/disconnect of kegs and valves
• Solenoids serve as check valves (normally closed), allowing unpressurized beer line when not activated. Also prevents backflow between kegs.
• Scalable to several more kegs
• Minimal foaming
• Cool clicking sound from the valves

Downsides:

• A small amount of beer (~10 ml) is left in the tubes from the last serving. This needs to be purged (consumed) when serving from a different keg.
• Only one beer at the time can be served.
• One tap fits all. No fancy nitro faucets and such.
• The LEDs are very bright. Blinding hazard.

I currently serve a Belgian Dubbel, an American IPA, an American APA and an English APA through the contraption. It works quite well for all of them.

Cheers!

 

[John Paul Stoddard]

Cool.....But I am guessing you don't have a lot of friends over and need to serve a lot of beer.
I would bartend for sure to make sure people are not simply pouring out the first runs on each switch. I know I wouldn't want an IPA in my glass of Dubble.

While cool, I would rather just go the expense of 3 More Taps.

 

[DaWhip]

That is awesome. I love the "no digital electronics" requirement. Wiring stuff up "old school" with switches, knobs, and pots is a blast. If you made changes with the goal of reducing the amount that needs to be purged when switching kegs, how small of an amount do you think you could get to?

 

[DaWhip]

Oh, and I just noticed the lights indicating which beer is selected. very cool.

 

[BryskeBrynolf]

That is awesome. I love the "no digital electronics" requirement. Wiring stuff up "old school" with switches, knobs, and pots is a blast. If you made changes with the goal of reducing the amount that needs to be purged when switching kegs, how small of an amount do you think you could get to?

It's pretty minimized as it is. The residual volume is just in the 60 cm tube between the "hub" and the tap. A few ml. I could of course move the hub very close to the tap, but that would require four tubes all the way there whitch would defeat the purpose of reducing tube hassle.

If I had the room I would put the tap on the side of the fridge instead of on the door. That would make this easier. And honestly, unless you serve drastcally different beers (like a stout before a pilsner) I don't think you'll notice if you skip the purging.

 

[BryskeBrynolf]

On reflection, there's probably a larger volume in the shank than in the tube. This is hard to avoid...

 

[BeardedBrews]

This is awesome! Not something I need, but I love the planning and thought that went into the design.

 

[pigroaster]

Could you give an approximate cost with the listed items you used? Neat concept! I bet you are great at serving a black and tan!

 

[BryskeBrynolf]

Could you give an approximate cost with the listed items you used? Neat concept! I bet you are great at serving a black and tan!

Roughly
Valves: 20$
JG couplings: 30$
Switch, LED, terminal blocks: 15$
Power adaptor: 10$
TOTAL: 75$

And yes, it's tempting to turn the switch back and fourth frantically and persistently while pouring a pint. A world of new discoveries

 

[DaWhip]

It's pretty minimized as it is. The residual volume is just in the 60 cm tube between the "hub" and the tap. A few ml. I could of course move the hub very close to the tap, but that would require four tubes all the way there whitch would defeat the purpose of reducing tube hassle.

If I had the room I would put the tap on the side of the fridge instead of on the door. That would make this easier. And honestly, unless you serve drastcally different beers (like a stout before a pilsner) I don't think you'll notice if you skip the purging.

My current practice is swapping a single picnic line between kegs, so I'm used to purging it (or not caring for similar styles). i don't think I'd mind the extra tubing, so I'd eliminate as much as possible. My 6ft picnic line holds half a mouthful of beer (measured very scientifically) so I can deal with it either way. Really, I just dig the LEDs to indicate what is serving and might go this route for no other reason when I get a bigger kegerator, haha.