Place the milk in a saucepan and gently heat to 180°F. Meanwhile, split and scrape the vanilla bean to add to the milk and keep an eye on the temperature. Once the temperature is reached, remove from heat and let it cool to 100°F. Whisk in 1 package of the yogurt starter and the vanilla. This spreads the good bacteria and vanilla throughout the milk.
Place milk in yogurt jar or jars without lids and incubate in your yogurt maker for 6-8 hours at 100 to 110°F. I do mine at 110°F and it takes 6 hours, If you use cooler temps like 100°F it can take up to 8 hours. If it is too warm, all the good bacteria will die, so a consistent, luke-warm temperature is paradise for all the good bacteria and promotes their growth. You'll know it's done when you see a thick curd.
Place the jars in the fridge to cool and set. Cool the yogurt in the refrigerator for a couple of hours. As the yogurt cools it will get even thicker!