Each time you make yogurt you will need starter yogurt that has been made with active live cultures.
(Buy a small container of plain yogurt at the grocery store and make sure it says “Made with Live Cultures.'')
You can also use your own starter, but over time, it loses its potency.
Starter yogurt can also be frozen in ice cube trays, for convenience.

Plain Yogurt Recipe
4 cups whole milk (2%,1% or part heavy cream)
2 Tbsp plain yogurt

Heat milk until it reaches between 170-180°. Allow to
cool to 105-110°. Add the yogurt and combine well.
Place in L’Equip FilterPro dehydrator yogurt cups and set temperature to
115° for 4-6 hours, until desired thickness is reached.
Store in airtight containers in refrigerator for up to one week.

For Greek style yogurt:
Use 2 cups whole milk and 2 cups heavy cream. Proceed as above.
Once the yogurt is thick, place 2 paper towels in a mesh
strainer over a bowl. Pour yogurt through paper towels and let drain for
2-4 hours in the refrigerator. If the yogurt becomes too thick, stir some of the whey back in.
(Use the whey as part of the liquid when making bread or in other recipes.)

You can add sweeteners, granola, preserves, or fruit to flavor the yogurt after culturing.
Don’t over stir the yogurt or it will separate. Fold in additions gently.
Reserve part of the yogurt as your starter for the
next batch. If, over time, the taste becomes too sour, use a fresh starter from commercial yogurt.