Those amongst you that are cooks won’t need this explanation, for the rest of us, lets just get this out of the way. Sous Vide is when you cook things at a temperature lower than normal, for a period of time longer than normal to attain specific results in texture. A chef can tell you more intricate details about it, but what we care about is how to impress our friends with a cheap hack and a tasty meal. This video shows how to hack your slow cooker for precise temperature control. Well, it really shows how to splice a temperature controller into an extension cord, so we guess it could be used for a ton of things, non Sous Vide related.
Here are the contronl modules for a sous-vide project over at Nerdkits. [Humberto] and crew continue doing a great job of focusing a project on one goal, then explaining the steps needed to get there. In this case they wanted to build their own sous-vide appliance that was cheap, and didn’t really require the user to deal with mains voltage. We like it because most of the parts can be found at a hardware store and big box store.
He started with a slow cooker, which is pretty standard. Next he needed a way to switch power to the device. Instead of using a solid state relay, he went for a standard dimmer switch. It’s build into a double gang electrical box, and controls an outlet which is occupying the second position in that box. Now current to the slow cooker is limited by the position of the dimmer. The next task was to add a cardboard frame which marries a servo motor to the dimmer’s knob.
With the control scheme in place [Humberto] needed a feedback sensor. He built his own water proof temperature probe by covering an LM34 temperature sensor with shrink tube and sealing the ends. Just one probe in the cooking water isn’t very reliable so he added a second between the slow cooker’s base and ceramic vessel to improve the performace of the PID algorithm. He goes into detail about that in the video after the break.
Continue reading “A Simpler Sous-vide Hack”
We’ve seen no shortage of temperature controlled immersion cooking devices, called Sous-Vide, around here. But this one probably has the capacity of all of them combined! Flickr user [RogueGormet] isn’t writing about the build, but his Large Form Water Oven build photo set speaks for itself.
We’d wager that the donor vessel is a 16-gallon chest cooler. He cut the lid into two sections, sealing off the insulated cavity with High Density Polyethylene (the stuff those white cutting boards are made out of). This gives him a place to mount the heating element, with a box for the PID controller riding on top. A submersible pump keeps the liquid moving to help regulate the cooking temperature throughout.
What do you put in one of these? Right off the top of our heads we’d think he had something like a pig roast planned. But it could just as easily be a Turkey, or other large hunk of meat. What would you use it for?
If you don’t need quite as much capacity you might make some alterations to your slow cooker for your own immersion cooking.
It seems that sous-vide cooking is becoming increasingly popular lately. [Meseta] caught the sous-vide bug and wanted to try his hand at it, though he did not have enough money for a premade sous-vide cooker. After seeing a good handful of lackluster DIY sous-vide rigs online, he decided that he would design and build a sous-vide cooker of his own.
He already had a Forebrain microcontroller at his disposal to use as a PID controller, but what he really needed was a cooking vessel. Rather than use an old crock pot or similar device, he purchased a small personal refrigerator that could be used for cooling or heating. The unit ran off a Peltier cooler that could be switched between modes, making it quite easy for him to control.
In his blog, he discusses the modification from beginning to end, and even shows off the results of his cooking endeavors. He hasn’t posted code as of yet, but he says that he is more than happy to share it with anyone who might be interested in building their own sous-vide cooker.
In search of a perfectly-cooked brisket, [Aaron] recently completed this DIY PID-controlled sous-vide slow cooker. Sous-vide (French for “under vacuum”) is a cooking technique in which foods are typically vacuum-sealed and then cooked in a relatively low temperature water bath for an extended period of time. This is done to minimize temperature gradients throughout the food to ensure even cooking. Precise regulation of the water temperature is the key to ensuring that the results are exactly as desired – when cooking for many hours or days, even a few degrees discrepancy can greatly influence the final product.
A few months ago we featured a similar hack that utilized a simple switching temperature controller spliced into an extension cord. Although probably sufficient for most aspiring “hacker-chefs”, the temperature was not as stable as it could be. The problem is that it takes time for the heat generated in the slow cooker’s heating element to reach the temperature probe (and food) suspended in the water bath. By the time the probe reads the elevated temperature, the element is already too hot and the temperature overshoots the target. One way to mitigate this effect is to circulate the water to minimize temperature gradients, as is done in many of the expensive commercial units. In order to achieve similar results, [Aaron] instead created a PID controller that uses temperature feedback over time to precisely maintain the desired temperature and reduce any deviations resulting from outside disturbances.
The build is covered in detail and looks great in a custom acrylic enclosure. All of the board schematics, enclosure layout files, and source code are available under Creative Commons licensing at the bottom of his blog page. A good deal of time is also spent addressing the actual PID programming and tuning – something that could be useful for many different hacks requiring precise feedback control.
The end result is a professional looking control box and a slow cooker that is able to maintain temperature within 1°F even while using a DS1820 temperature sensor that is only rated as accurate to 0.5°C (0.9°F). From the pictures it looks like [Aaron] has finally achieved brisket bliss! Now the only question remaining is: what is the best setting for reheating left-over pizza?
[Craig] pulled off a beautiful build with his Sous Vader project. The name is a geeky spin on sous vide, a method of cooking foods in water held at a precise temperature. Building your own setup at home saves a ton of money, but it’s also a lot of fun. This explains the frequency with which we see these builds here at Hackaday.
So this one has a flashy name, a fine-looking case, but the beauty continues on the internals. [Craig] posted an image with the cover off of the control unit and it’s absolutely gorgeous inside. Part of the reason for this is the circuit board he spun for the project which hosts the ATmega328 and interfaces with the LCD, buttons, temperature sensor, and mains-switching triac. But most of the credit is due to his attention to detail. The image on the right shows him prototyping the hardware. Since some of his meals take 20 hours to prepare it’s no wonder he found an out-of-the-way closet in which to do the testing.
Make sure to read all the way to the bottom of the post for some cooking tips. For instance, since he doesn’t have a vacuum sealer he uses zipper bags — lowering them into water to push out the air as they are sealed.
[Alan] was unimpressed by the cheap ticking egg timers that grace many of our kitchens. He decided this was an execllent opportunity to ply his skills with microcontrollers. He built this kitchen timer complete with an enclosure and audible alarm.
The device is Arduino based, which makes driving the graphic LCD quite easy thanks the libraries associated with that platform. As you can see above, his user interface makes use of virtual buttons – three tactile switches whose function is listed at the top of the display.
But we think the alarm sound really earns this a place in his kitchen. He used the same hardware as that that Super Mario Bros. Toilet project to play classic video game sounds when your soufflé needs come out of the oven. We haven’t come across them ourselves, but apparently there’s a line of key chains for sale in Japan (yes, we need to plan a trip there!) that have the tunes programmed into them. They’re easy to crack open and it beats dealing with a speaker and amp circuit.