Margarita Drip Infuser Ensures a Perfect Mix

In order to get a margarita just right, the various ingredients need to be mixed together quite vigorously to over-come the different viscosity of the fluids. Looking to create his own barbot of sorts, [TVMiller] decided to make a Margarita Drip Infuser to help make margaritas a bit easier.

Using various chem lab supplies, [TVMiller] has cobbled together something pretty awesome. The Infuser can take up to 8 different ingredients into its test tube reserves, and after the drink ingredients are programmed on the computer, the magic begins.

An Arduino Uno controls a bank of 8 relays which control small fluid solenoids, with each control pulse releasing just a single droplet of fluid. An LED for each valve is run in parallel adding a bit of a light show to the mixing experience. If that’s not enough, he’s also created a copper cooling coil to chill the drink as it is poured.

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Keep an Eye on Your Fermenting Beer with BrewMonitor

The art of brewing beer is as old as civilization itself. Many people enjoy brewing their own beer at home. Numerous steps must be taken before you can take a swig, but fermentation is one of the most critical. [Martin Kennedy] took up the hobby with his friends, and wanted a convenient way to monitor the fermentation temperature remotely. He started working on the BrewMonitor, a cloud-based homebrewing controller powered by an Arduino clone.

His goal was to create something cheap, convenient, and easy to set up. Traditional fermentation monitoring equipment is very expensive. The typical open-source alternative will set you back 80 euros (roughly $101), using the Arduino-sensor with a Raspberry Pi gateway via the BrewPi webserver. [Martin] did not want to go through the hassle of viewing BrewPi remotely, since it requires a home network and all of the configuration that would entail. Instead, he coupled an Arduino clone with a DS18B20 temperature sensor while using an ESP8266 module for wireless communication, all for less than 18 euros ($23). This connects to a simple webpage based on with a PHP backend (Laravel with RESTful API), a MySQL database, and an AngularJS frontend to display the graph. Once the sensor is placed into the fermenter bucket’s thermowell, the temperature is transmitted once a minute to the REST API. You can see the temperature over time (in Celsius). The design files are available on GitHub.

[Martin] would like to expand the functionality of BrewMonitor, such as adding the ability to adjust the temperature remotely by controlling a heater or fridge, and lowering its cost by single boarding it. Since the information is stored on the cloud, upgrading the system is much easier than using a separate gateway device. He doesn’t rule out crowdfunding campaigns for the future. We would like to see this developed further, since different yeast species and beer styles require very stringent conditions, especially during the weeks-long fermentation process; a 5-degree Celsius difference can ruin an entire brew! Cloud-based temperature adjustment seems like the next big goal for BrewMonitor. DIY brewers salute you, [Martin]!

[via Dangerous Prototypes]


End Table Kegerator Hides the Tap when You’re Not Looking

What’s better than an ordinary end table? How about an end table that can serve you beer? [Sam] had this exact idea and used his skills to make it a reality. The first step of the build was to acquire an end table that was big enough to hold all of the components for a functional kegerator. This proved to be a bit tricky, but [Sam] got lucky and scored a proper end table from a garage sale for only $5.00.

Next, [Sam] used bathroom sealant to seal up all of the cracks in the end table. This step is important to keep the inside cold. Good insulation will keep the beer colder, while using less electricity. Next, a hole was cut into the top of the table for the draft tower.

The draft tower is mounted to a couple of drawer slides. This allows the tower to raise up and down, keeping it out of sight when you don’t want it. The tower raises and lowers using a simple pulley system. A thin, high strength rope is attached to the tower. The other end is attached to a spool and a small motor. The motor can wind or unwind the spool in order to raise and lower the tower.

The table houses an Arduino, which controls the motor via a homemade H bridge. The Arduino is hooked up to a temperature sensor and a small LCD screen. This way, the users can see how cold their beer will be before they drink it.

To actually keep the beer cold, [Sam] ripped apart a mini fridge. He moved the compressor and condenser coils to the new table. He had to bend the coils to fit, taking care not to kink them. Finally he threw in the small keg, co2 tank and regulator. The final product is a livingroom gem that provides beer on demand.

Demo video (which is going the wrong way) can be found after the break.

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The Fridge Hacking Guide by BrewPi


The team behind BrewPi are at it again! This time they have created an online guide showing how to convert a min-fridge into a Raspberry Pi & Arduino controlled fermentation chamber. In it, they describe 3 possible options:

  • Option 1: Make a simple switched power cord, without hacking into the fridge electronics.
  • Option 2: Make a switched power cord, but also override or remove the thermostat.
  • Option 3: Rip out the thermostat and fully integrate the SSRs into your fridge (which is what [Koen] and [Elco] did).

First things first though. They had to clean the fridge. And depending on where they got it or how long it has been unplugged for, the inside might have been pretty rank and disgusting from mold growing out of every corner. This took a good hour or so to clean properly lest the brewing process get infected with external grossness. This is all worth it because a well-controlled fermentation chamber results in a superior batch of beer.

They put their laser cut case on top of the fridge, holding an LCD, Raspberry Pi, Arduino and the BrewPi Arduino shield. The Arduino reads the temperature sensors inside the fridge, the beer and the ambient temperature. Then it controls the SSRs they added to switch the compressor and a heater. Then, the cables were routed through the fridge and take control of the compressor.

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Temperature Controller Gets Open Source Firmware Upgrade


Beer lovers rejoice! [Mats] has reverse engineered a temperature controller and written new open source firmware for it. This effectively gives all us homebrewers a low cost, open source software driven controller. The STC-1000 is a cheap (under $20 USD) temperature controller mass-produced in the far east. The controllers do work, but have several limitations. The programming options are somewhat limited to basic set points for heat and cool. The controller also is only programmed for temperature display in Celsius, which is a bit of an annoyance for those of us who think in Fahrenheit. Under the hood, the STC-1000 utilizes a Microchip PIC16F1828 microcontroller. Unfortunately the PIC’s protection bits were set, so the original code would have been extremely difficult to extract. Not a problem, as [Mats] reverse engineered the hardware and wrote his own firmware. A 10k NTC thermister acts as the temperature probe. The probe is read by the PIC’s ADC. These probes are not very linear, so a look up table is used to convert from volts to degrees Celsius or Fahrenheit.

[Mats] new firmware allows for up to 6 profiles. Each profile has up to 10 set points and a time duration to hold each of the set points. Hysteresis and temperature offset values are also programmable via the front panel. PIC software is often written in C using Microchip’s MPLAB tool chain, and programmed with the PICkit 3 In Circuit Serial Programming (ICSP) tool. [Mats] decided to buck the system and wrote his C code using Small Device C Compiler. To keep things simple for homebrewers who may not have Microchip tools, [Mats] used an Arduino Uno for flashing duties. Thankfully the unholy matrimony of a PIC and an AVR has not yet caused a rift in time and space. The firmware is still very much in the beta stage, so if you want to help out, join the discussion on the homebrew talk forum. If you see [Mats] tell him we owe him a Haduino which he can use to almost open his beer.

[Thanks for the tip Parker!]

Smart Kegerator Bills Based on Beer Consumption

Kegerator ownership is awesome, but it has its downsides. It’s hard to keep track of who drank what without cans or bottles to count. [Phil] was looking for a good solution to this problem when it came to sharing beer with his roommates and friends and has just completed the first iteration of his smart kegerator.

He has devised a system based on a Raspberry Pi.  His software recognizes the face of the person pulling a beer and adds a charge to their tab based on the price of the keg and the volume of the pour. The system also keeps track of current and historic temperature and humidity values inside the kegerator, and everything is displayed on a Mimo 720S touch screen.

[Phil] has a flow meter on each keg to detect and monitor pouring. This triggers the Pi camera module to run the facial recognition. The walk-through found after the jump might be a bit confusing; at the time it was recorded, the unit was only capable of facial detection. [Phil] wrote the UI in QT and C++ and used Python scripts for the flow interrupts. His plans for future iterations include weight sensors underneath the kegs, liquid probe thermometers for more accurate beer temperature readings, a NoIR Pi camera module for low light conditions, and a really snazzy UI that you’ll see on his build page.

If you don’t have a Pi, here’s an Arduino-fied kegerator that reports temperature and controls beer cooling.

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Fetching Etchings for Stainless Steel

What do you do when you have a 10-gallon brew kettle (or any other stainless steel or aluminium thing) with no volume markings (or Hack a Day logos)? If you’re [Itsgus], you use science to etch some markings with a few household items and a 9V and you call it a day.

[Itsgus] used 1/4c vinegar and 1/4tsp of salt to form an electro-etchant and applied it with a Q-tip connected to the negative terminal of a 9V. He used tape to connect a wire between the positive terminal and the kettle. The vinegar dissolves the salt, creating negatively charged ions. Connected correctly to a 9V, the process removes metal where the current flows. If you were to connect it in reverse,  you would add a small amount of metal.

The process only takes a few seconds. When the etchant starts to sizzle and bubble, Bob’s your uncle. Even though the stainless steel’s natural coat re-oxidizes over the etches, you should probably wash that thing before you brew. If you prefer adding metal to removing it, try electroplating copper on the cheap.