Janet Fletcher, author of Yogurt, shows us step-by-step instructions for easy DIY yogurt
Thick, creamy yogurt is a staple in many kitchens, including our Test Kitchen. Janet Fletcher’s technique creates tangy and creamy yogurt with simple tools and ingredients–no fancy equipment or yogurt maker necessary. She uses whole milk, instant nonfat dry milk, and plain whole milk yogurt with active live cultures.
Start by filling a clean, wide mouth 1-qt jar with hot water and set it aside. The hot water warms the jar so it can properly incubate the yogurt later. Next whisk together whole milk and instant nonfat milk in a medium sauce pan. Heat the milk over medium heat, whisking frequently, until it reaches 195° on a thermometer. Continue to whisk the milk and cook it for 10 minutes at 195°, adjusting the heat if necessary. Remove the milk from the heat and set the pan in a sink or large bowl of ice water until the milk drops to 115°.
The milk cools rapidly, so keep checking it or use a thermometer that gives a continuous reading. If the temperature gets too low, you can reheat the milk. But don’t let it go back above 118° or you risk killing the yogurt.
Put the yogurt in a small bowl and whisk in a cup of hot milk to temper and thin it. Whisk the mixture into the milk in the pan before draining the hot water from your jar and adding the hot milk mixture. Put the lid on and incubate the yogurt by wrapping it in a kitchen towel and multiple blankets. Let the yogurt sit undisturbed in a warm place for five hours before unwrapping it and tilting the jar gently to check if it’s set. It should behave like a baked custard. If it’s not set, rewrap it and check in another 1-2 hours. The longer your yogurt cultures, the tarter it will taste. Chill completely to firm up the yogurt before serving.