Beer Security System Keeps Freeloaders Out Of Your Stash


The crew at the Milwaukee Hackerspace are pretty serious about their beer. They used to have a fridge filled with cans, available to all at the hackerspace, but they decided to beef things up and create a secured beer dispensing system.

Like many others we have seen, their kegerator is built into an old refrigerator, complete with a tap built into the door. To ensure that interlopers are kept from their precious brew, they have secured the refrigerator using an Arduino and RFID tags to grant access. They use the same RFID key fobs members carry to gain access to the space for tracking beer consumption, unlocking the tap whenever a valid tag is swiped past the sensor.

They are still in the midst of tweaking and revising the system, but it looks good so far. It’s a great way to keep uninvited guests from their beer stash, while giving them a way to track consumption at the same time. We’re looking forward to seeing more details and code once things are completely wrapped up.

[via BuildLounge]

29 thoughts on “Beer Security System Keeps Freeloaders Out Of Your Stash

  1. I keep seeing these awesome hackerspace hacks…

    Can’t find one near me, though there’s a plethora in the SF Bay Area. -.- There’s Sac Open Shop, but they don’t have a … shop. :p

  2. “Beer Automated Dispensing And Security System”

    BADASS :) I agree,but… Not really sure if making access beer & power tools, at the same time is a good idea for places alike makerspace. Don’t get me wrong I like beer , and known to have a bottle open while doing work around my place. Getting between a man or women, and their beer can be problematic, if ever need be. I wouldn’t be surprised if the inspector for their insurance company tells them to get rid of it next time they drop by. Liability insurance insurance,incorporation and non-profit status often go hand in hand, to attract member with deeper pocket, who often donate a lot, and other donations.

  3. Another Wisonsinite here….

    There are those of us who would pay good money to have a setup like this for party night. Sometimes its difficult to keep certain people out of the fridge who shouldn’t be in there.

  4. I did something similar back in 2002 only I retrofitted a vending machine for metered dispensing from two kegs (while keeping 1/2 of the capacity operational for can/bottle vending)

    The only real problem was that the valves and flow meters I used to control and measure the flow of beer severely interfered with pour quality. I could not balance the system correctly with inline solenoid valves and impeller-based flow meters. Beer would come out as 100% foam. I found flow meters from Auper that can measure the flow of beer without using an impeller but they were fairly expensive. So since I couldnt solve the problem for the valves, I never ordered them, and the metering and faucet control went to the honor system.

    Other than the description here on HAD I can’t find any description of how they are “locking” the tap handle. My hope is that they have found a handle which can be electromechanically disabled/enabled, and I might be able to use something similar to finally meet the design goal of my earlier project.

    If anyone involved in this project can comment about this aspect, I would appreciate it.

    For anyone curious, I never finished writeups, but photos are available at This pretty well pre-dated arduino, so this project used a Basic Stamp 2 on a custom board with the various control electronics needed to run the valves and flow meters, interface with the vending electronics and mechanics, and provide calibration controls.

    1. John, Wifigod what about using a timer? instead of measuring the flow of beer. If you assume beer will dispense under a constant pressure from the CO2 you could time a pint pour and have a perfect amount. Maybe you could also collect the time from all pours and use it to drive an indicator light for CO2 and Keg replacement.

      1. How about using weight?

        You have a little shelf to set the mug upon when it’s being filled. The moment someone sets the mug down, the scale weighs it and records the value.

        Beer comes on and continues to flow until the weight equals the prior weight plus the desired quantity of beer.

  5. Also, I do want to second what John mentioned about balancing and foam. I’m currently testing a few different solenoids in search for the perfect one, so please let me know if there are ones I should try; so far, my flowmeter (SwissFlow 800) isn’t causing much issue with the pours.

  6. I’d totally join that hackerspace, but that’s quite a bit of money. for 6 weeks of MHS membership, I can join the West Allis Auto Club for an entire year.

    Defcon 414 Milwaukee is $5 or donation of food per monthly meeting.

    Not saying the cost isnt justified; just looking at numbers.

    Cool hack, I like it! Now to get the Defconians to hack it with RFID cloning :) They’d totally do it if it were a keg of Rolling Rock

    1. Well, you can certainly join the West Allis Auto Club, or attend the Defcon 414 meetings, but I think what Milwaukee Makerspace offers is a bit different. We’ve got members who have built electric cars in the space, utilizing the all the tools we’ve got as well as the fact that we can fit a bunch of vehicle *inside* the space as well as knowledgeable people who have done it before who can assist you.

      We’re open to anyone who wants to stop by on a Tues or Thurs night at 7pm for a tour and to meet the members. A makerspace isn’t for everyone, but it you like to collaborate on stuff like this kegerator, you might find it a cool place to do so.

      1. Oh, I’m not saying I wouldnt love to come and help (And I was previously a member of WAAC). I’m just saying that with the amount of time I have (near null) I would probably get under three days use of Hackerspace Milwaukee. Looking back, I’d said not exactly what I’d meant.

        I’ll take you up on that tour offer (I’ve seen the vids, they got me all excited to check it out). I feel I may not be able to join, despite the resources you guys have. Still, It’d be fun to spend some free time there if expertise in my field is needed. For now I’ll concentrate on dc414, I need to learn a bit more about that flavor of things first.

        See you soon!

  7. Lots of important details missing. Like Flow control. I have yet to find any solenoid valve that does not screw up the beer pour quality. and good food grade ones that are all stainless and NO brass to keep you from being poisoned are highly expensive. I hope they did not just use Post-mix soda valves because the alcohol in the beer will dissolve the lubricant in the valve while soda does not.

    Finally, Nice idea, but just find a old sodapop vending machine and hack that. it ends up far easier to deal with and cheaper in the long run.

    WE even gave up on the RFID and other junk and simply changed it back over to quarters. $1.25 a beer covers the cost of the beer and adds money back into the groups coffers to keep the lights on and the C02 fire extinguishers filled. No more worrying about someone pilfering beer, if they dont have money, they dont get beer or soda.

    Still in search of normal can sized energy drinks..

    1. What’s up with brass? They’ve made tankards out of it for long enough. Not to mention pewter. Surely a little bit isn’t going to kill you. I’d be more worried about the energy drinks doing your cardiovasculars in.

  8. I really don’t see how this would stop a thirsty one from breakin the friggin fridge open, pissing on the arduino and stealing your beer. this is a geek only security. go in by force, and you’ve got more loss in broken components than the price of beer…

    1. An RFID or PIN is needed to enter the hackerspace.
      The “thirsty one” would already have to be in there. A list of who was in the h’space when the fridge got fracked would help identify the “thirsty one”, who’s own RFID would “probably” not be listed in the fridge log. It is possible that with so much “neat stuff” in the h’space they have some form of video surveillance as well.

      But then there is that old saying, “locks are only made to keep out honest people”.

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