Danger Brewing: The JavaScript Powered Kegerator

This is a story about a completely unnecessary, over-engineered appliance that dispenses beer, has its own web application and reports data in real-time.

I wanted to keg my own beer since I started brewing 7 years ago, mostly because bottling beer is the worst. The initial plan was to build a collar-style keezer. But then I remembered I’m a software engineer, I like building things and I love a flimsy pretext to interject technology.

Project Goals

• Know how much beer I have left in a keg
• Monitor the temperature of the fridge
• Look like a piece of furniture rather than an appliance

Just To Say It

Some important things to point out:

• This project isn’t economical — nor did I try to make much effort to be economical.
• There are hundreds of ways to approach this project. I do not claim that this is the best approach by any means; it’s just how I went about it.
• It’s completely unnecessary (but in our crazy world, very necessary).
• Huge shout out to my buddy Mark who luckily for us, uses his tools and craftsmanship for good and not evil. I couldn’t have done it without him.
• Also a huge shout out to my wife who was more than patient.

Freezer build

Here’s where the journey started:

This is an off-the-shelf chest freezer from Home Depot, more specifically, this one. What may be the reason why I even embarked on this build in the first place is that a non-white chest freezer doesn’t exist. You can find a few of them out there, but they’re either enormous, too small or are trying to hide from other freezers. None of those traits are acceptable for my purposes, so I purchased a white freezer and wrapped it in wood. The inspiration of which can be found here.

There’s a 2x4 skeleton around the freezer.

With a similar skeleton around the lid.

The original goal was to use reclaimed wood, pallet wood or something up-cycled. This proved to be quite difficult to find enough consistent building materials. I ended up using generic “white wood” (I’m still not sure what this is exactly) and pine from the hardware store. The “reclaimed” look was inspiration from Young House Love. The wood was roughed up randomly and stained with two different colors at different time intervals.

No worries about the freezer exhaust, it was accounted for:

The draft towers are off the shelf 1.25" galvanized steel pipe and fittings. Most I was able to acquire locally with only a few pieces requiring purchase online.

One last finishing touch, a skull bottle opener and cap catcher.

To see more of the build process in detail, click here.

Kegerator Build

The freezer I purchased fits three corny kegs (maybe a fourth if it was smaller in size and the gas tanks were on the outside), however there are four taps. This was so I could operate 3 CO2 beers at once or some combination of CO2 and Beer Gas (nitro).

There’s the standard equipment involved:

• 3 Cornelius (corny) kegs
• 1 dual CO2 regulator and tank
• 1 NO2 regulator and tank
• 3 faucets, 1 stout faucet
• Beer and gas lines, shanks, fittings, etc.
• 1 temperature controller

To circumvent future moisture issues, an ingenious air flow solution was built, which I aggressively borrowed from here.

The goal here is to keep some air circulating in the freezer to prevent mold and keep a consistent temperature. Because I chose not to build a collar or alter the height of my freezer, my implementation deviates from the original a bit. I couldn’t physically accommodate 2" PVC with kegs vertically so I only built half of the air flow solution — which works just as well.

Technology

Aside from monitoring keg volume and temperature, I wanted to use this project as a means to learn some new technologies. The kegerator is conceptually two main components:

• The hub - a Raspberry Pi
• The web application - built with Ember

The hub is a Raspberry Pi that sits on the lid of the kegerator (mostly just to look awesome).

It is responsible for collecting sensor data and reporting it to my web application. There are three sensors being used:

• Flow meters — these are built into the beer lines and record liquid that passes through them.
• Temperature sensor (in the fridge) — monitors the freezer temperature.
• Temperature sensor (in the lid) — monitors temperature and humidity around the draft towers, outside of the freezer.

The hub is running a Node application, built using Johnny Five. The data it collects is reported to Firebase. The web application is using the same Firebase project as its data source.

To read more about the technology build process in detail, click here.

Wrapping Up

This project took a lot longer than I had anticipated. I was often discouraged, spent too much money and learned lessons the hard way. But ultimately, when I poured that first beer and saw my web application update in real time — holy. shit.

To see what I have on tap at any given moment or want to see how my freezer is doing, the web application can be found here: dangerbrewing.io. It’s currently hosted for free, so it may be slow to load. If you’re a complainer or some kind of jerk, feel free to send some dollars my way to fix that.

To read more about the build process, click here. Or to read more about the technology involved, head here.

If you embark on a similar journey, I’d love to hear about it.

Cheers!