Homemade Yogurt

When our little one reached 6 months and we went to see her pediatrician, we talked about the foods that we can start with. She told us we can start with vegetables, fruits and yogurt. So when I came home I called my mom who is an expert on homemade yogurt. Because I think yogurt is a great food for babies also for adults.
The method is very basic, you don't need special yogurt cultures or any  incubating equipment. 
All you need to make homemade yogurt is milk and any kind of plain yogurt. You can use skim milk if you like, but whole or 2% fat milk will make the thickest yogurt. 
When I make yogurt I am using a gallon of 2% fat milk, for the culture we bought a probiotic plain yogurt, after starting with that yogurt we continue to make yogurt with our own yogurt. 

What You Need

Ingredients

1 gallon milk — whole or 2% are best, but skim can also be used
8 table spoons of plain yogurt 

Equipment

Large saucepan or pot with a lid
Spatula or spoon
Thermometer 
Small bowl
Table spoon
2 pyrex 11 cup glass dishes with plastic lids
Towel or a thick cloth

Instructions

1. Heat the milk. Pour the milk into the pot and set over medium to medium-high heat. Stir the milk gently as it heats to make sure the bottom doesn't scorch and the milk doesn't boil over. After half hour turn off the oven.
2. Cool the milk. Stir occasionally to prevent a skin from forming while cooling. Let the milk cool until it is just warm to 113°F. If the milk more cooler than 113°F, you can warm it up a little bit. It is said that optimum heat of the milk is between 107.6°F and 113°F for fermantation. But I am using 113°F (a little bit higher or lower will be ok) because while we are adding yogurt for fermantation the milk is cooling a little bit. And one more useful detail when you pour your milk into your glass dish just after cooling process your milk's heat can decrease so you can cool your milk directly into your glass dishes. 
3. Thin the yogurt with milk. Put your 4 table spoons of yogurt (for half gallon milk) into a small bowl and add some milk from the one that you warm. Add milk until the mixture is looking liquid and whisk it until smooth and the yogurt is dissolved in the milk. Repeat this process for the second glass dish. 
4. Whisk the thinned yogurt into the milk. Pour the thinned yogurt into the warm milk while whisking gently. This inoculates the milk with the yogurt culture.
5. Wrap glass dishes into a bath towel or a thick cloth. Put your lids onto your glass dishes but don't close them. There must be a little bit openning for fermantation. Wrap these glass dishes into a bath towel seperately. 
6. Wait for the yogurt to set. Let the yogurt set for at least 4 hours or may be 12 hours. The exact time will depend on the cultures used, the temperature of the yogurt, your home tempereature and your yogurt preferences. The longer yogurt sits, the thicker it becomes. But after one point will get sour so you need to check occasionally. You can check your yogurt by lifting one edge of the dish a little bit. Avoid jostling or stirring the yogurt until it has fully set. If this is your first time making yogurt, start checking it after 4 hours and stop when it reaches a  consistency you like. 
7. Cool the yogurt. Once the yogurt has set close the lids and let them cool in the refrigerator for 24 hours. And after that you can enjoy to eat your homemade yogurt.