Sous vide, literally meaning "vacuum" in French, is a method of cooking that uses a water bath to cook vacuum sealed foods to exact temperatures. Steaks, for instance, can be cooked to perfect medium rare with incredible texture and flavor without fear of over/under cooking. Sous vide machines are pretty pricey but there are a few new models coming out aimed toward the home cook. Although cheaper, they're still fairly expensive at $199+.

When I first read about cooking food sous vide I was very interested, but I didn't want to spend a few hundred dollars on a machine to experiment with. I did some searching and stumbled upon a few homemade sous vide machines using the STC-1000 temperature controller. It's cheap, available on Amazon, and came with just about everything you need for a primitive sous vide setup. I already had the other main component, a crock pot. Note that digitally controlled crock pots will not work with this setup because the STC-1000 is going to be cycling the crock pot on/off. Digital versions reset to "Off" when they lose power. Make sure the crock pot you will be using has a knob to select the temperature. A vacuum food saver isn't completely necessary but it does make things easier. Ziploc sells a cheap vacuum pump bag otherwise you can use regular Ziploc bags with the submersion seal method that I will talk about below. Here's the full list of parts you will need:

To make the controller, I used a Dremel tool to cut a hole into a plastic enclosure I had laying around. I drilled a couple holes in the back of the enclosure, one large hole for the extension cords and one smaller hole for the sensor. Once I had the STC-1000 fitted, I cut the extension cord and wired it up to the STC-1000 using a few wire nuts. I tied a knot in the sensor wire to keep it from pulling out of the STC-1000. I then used the included instructions to select a set temperature just above room temperature. The heating relay clicked on and an LED lit up on the STC-1000. Using a multimeter I measured the output of the heating relay to make sure it was providing the 120 volts. When I warmed the sensor up with my hand, the relay clicked off, and I verified 0 volts. I've included a wiring sketch below. I wired up the sensor, and sealed the enclosure. I then plugged in my crock pot and set the controller to a few different temperatures to verify the accuracy. All measurements were well within the reported ±1°C accuracy.