A baby can eat plain yogurt that has no artificially added flavors or sugars from 6 months old. Note that dairy is an allergen so when giving baby dairy for the first time keep a look out for any allergy signs. If you want to flavor homemade yogurt for baby then it is as simple as using a homemade baby food puree and mixing it with yogurt like this blueberry greek yogurt recipe, banana yogurt, mango yogurt or other baby yogurt recipes you can find here.