Making Perfect Yogurt Has Never Been So Delicious and Fun!
With Yogurtino & Yogurtino Jr, you make perfect yogurt every time.
You just need 2L of Whole Milk, or the milk of your preference, and a cup of natural yogurt, plus add a tablespoon of sugar to help the propagation.
What the Project does is to use an Arduino to control the milk temperature, alerting you the time to turn off the stove when the milk reaches 80 C and when it cools down to 45 C it beeps again to alert you on putting the yogurt to multiply. A rgb led blinks blue when it is below 45, green when it os between 45 and 80 and red when it exceeds 80C. Also a beeper tells you the time to turn off the fire, and when it cools the time to add yogurt, just like the kettle whistle! It is perfect for the hearing impaired or blind also.
Another option is to add an lcd and rtc for better reading.
The pot then rests overnight preferably with the lid on, around 8 hours, if you live on a cold climate, you may heat the pot again to reach 45 C, but in normal conditions it is not necessary. You should not overheat the yogurt because you can kill the good bacteria.
The result is very consistent yogurt, ou can add sugar and fruits or even add salt and olive oil to make delicious arabian dishes.
Step 1: Materials Needed
For Yogutino Jr: (simplest and economic version)
You will need an Arduino, uno or nano or Pro mini will do.
1 Rgb Led with 3x 400 Ohms resistors
1 Cell phone speaker with a 100Ohm resistor
1 NTC 10k Thermistor with a 10k Resistor to mesure temperature.
For Yogurtino: (deluxe version)
You can Add a I2C 16x2 LCD and a I2C DS3231 RTC Clock module.
for detailed temperature reading and tracking time.
Notice that both of modules uses the same 2 Pins on Arduino, it is very easy an hassle free to assemble.
You can find attached the Arduino Sketches for the two versions plus a I2c lcd guesser in the case your lcd does not work with the pin configuration provided.
Step 2: Yogurt!
Add the milk and the tablespoon of sugar, do not add the yogurt yet!
With Yogurtino assembled, you can wrap the termistor with some aluminium foil, to avoid contamination and to protect the plastic wire from temperature. Once this done stick the termistor end inside the milk and close the lid.
Heating the pot (best results with a heavy steel one), the speaker starts to beep and blinks blue untill it reaches 45C, then it stops blinking and blinks green, you wait untill it starts beeping again and blinks Red, It is time to turn off the fire. If you have the lcd, you can follow the temperature also.
Then you will wait something around 2 horus untill the milk reaches 45C and it starts beeping and blinking blue to tell you to add the yogurt, because it is already cool enough. Let the lid completely closed remove the termistor, and enclose in a stove or a cabinet to keep it warm. If you wish you can re-heat it after some hours untill the led turns green it meand that it is over 45. Take care to not heat it too much so you do not kill the bacteria that is making the yogurt! Have a good Time!
Let it at least 8 hours to act and open the pot to find rich and tasty Yogurt!