After year(s) of failures, here is a realistic DIY Yoghurt making tutorial. Using Thermos® and/or at least 8+ Hour heat retention rating flask. 

• Thermos® 1 Litre (or a smaller 530-650ML vacuum flask you may find at 8 hour+ heat retention rating)
• 150g Full Cream milk powder 
• 600ML water 
• 2 tablespoons of existing commercial yoghurt as starter 
• digital thermometre
• cheesecloth.

Instructionals

1. Pre warm the thermos with boiling water.
2. Reconstitute the milk powder by mixing in 150g and 600ML water. 
3. Heat either via stove or microwave ~ to bring temperature inbetween the critical range of 100-110 Degrees fahrenheit. 
4. Once the temperature is reached -  mix in no more than two (2) tbsp of existing commercial yoghurt. Blend this further with a blender to ensure even blending. 
5. Tip out the boiled water in the pre-warmed thermos, and pour in the mixture. 
6. During winters, make sure to use up to three (3) layers of cotton shirts as.a blanketed environment - wrap it securely around the Thermos®. Wait for at least a mandatory 24 hours.
7. Prep the cheesecloth - tie it around the saucepan. Carefully begin straining out the yoghurt. Wait for at least half hour or up to one hour. 
8. Store in the fridge for at least several hours before serving. 

Live-It-Forward,

AW™.