Let the milk mixture cool until it's warm to the touch, where you can comfortably keep your finger in it for a few minutes without it being too hot.

Add the 2 containers of plain yogurt to a bowl, scoop a ladle of warm milk into it, and stir until smooth. Strain this mixture into the pot of milk. Stir gently until well combined, then pour into jars and seal tightly.

The yogurt jars must be clean, or the finished yogurt will be slimy. If the jars haven't been used in a while, sterilize them with boiling water and let them dry before using.

Place the yogurt jars in a rice cooker. There's no need to add warm water. You can cover them with a towel to retain heat. Close the lid (without plugging in the cooker) and let it sit for 10 hours. The yogurt is successful when it sets and is smooth. If you prefer it more tart, leave it overnight (up to 20 hours). Then, refrigerate and enjoy the next day.

In the second image, I used a thermal cooker (without electricity) to ferment the yogurt because it holds more jars.

Important notes:

1. Heat the milk mixture until very hot, then let it cool to warm. Simply mixing with warm water may not work.

2. Do not move the jars while fermenting to prevent the yogurt from separating.

3. Use yogurt that is no more than 10 days old as a starter, or it may become slimy. You can also save 200g of your homemade yogurt as a starter for the next batch, which will taste even better!

Sometimes I pour the mixture into small plastic bags, tie them up, and ferment them in the rice cooker as described. Once set, freeze them for a treat reminiscent of childhood. My kids love it!

Mix yogurt with fruits and nuts for a delicious breakfast or snack!