Sous-vide cooking is a great new way of cooking food. I will not explain why and how it works here... for great recipes and explanations, you can check out those guys :
Unfortunately, a good (and I mean precise to the half °C) sous-vide machine is very very expensive (500, 1000$ or more). If you wonder why you need such precision, I suggest you check this out :
Some Arduino-based designs come cheap (50, 60$), but as they are based on PID regulation , they require adequate tuning to perform well. Good PID tuning is very hard to achieve in practice, so those designs don't hold well against reality (at least, in my experience). Also, who needs a 20$+ LCD screen when a cheap 5$ led 8-digits display does a better job in terms of readability.
After weeks of work and tests, I came up with my own design, with the primary goal of useability in mind. Behold the "Adaptative regulation sous-vide cooker"
automatic cut-off after 24 hours of operation
automatic cut-off when temperature reaches 95 °C
allows target temperature only in the safe 50°c to 90°C range
Parts needed :
You'll be set for approx 40$, maybe even less. That's not counting the rice cooker.