C of Habrahabra:
Ohhhhhh I decided to refine my yogurt because the temperature inside was too high.
The taste of the product is not suitable.
We need to control the temperature and time during the cooking process.
The power of the heating element is not high 15W, the simistor BT137x without radiator with opto-tyristor MOC3041 (D1) is suitable. As the “brain” of the design, the microcontroller ATTiny13A (U2) was chosen. Temperature sensor DS18B20 (U1)
The regulator scheme designed in Proteus looks like this:... (scheme drawing)
Eight hours of hard work with the solder and I assembled this scheme.
To control the power on the load, the microcontroller's hardware SIM was used, with the temperature adjustment of the work.
Once per minute, the temperature is measured, the value is compared, and the registry (OCRA) of the microcontroller responsible for the shrinkage of the system is adjusted.
Start preparing the right yogurt.
The yogurt feed cable is plugged into the regulator connector.
The switch indicator will start to flash, signaling the temperature sensor failure, click the 3.5 switch in the connector on the controller with the sensor at the end. The indicator lights up, not flashing, indicating the start of work.
The temperature is set at 38 degrees, the working time is 8 hours.
At the end of the cycle, the yogurt was no longer such a "rough" density and the sour taste disappeared. Wally!

YYYYY I solved a similar problem simply by placing a small towel on the bottom of the yogurt. The temperature dropped, everything was OK.