Thick and Creamy Yogurt

Pour hot tap water into a clean wide-mouth 1-qt. canning jar and set aside. Whisk together whole milk and dry milk in a medium saucepan. Heat over medium heat, whisking often, until milk reaches 195 ° on an instant-read thermometer. Adjust heat to keep milk at 195 ° and cook, whisking often, 10 minutes. After heating, "you're going to have a thicker, more stable curd," Fletcher explains. Remove from heat. Set pan in a sink of ice and water and cool to 115 °. "The milk cools fast, so keep checking it. If it goes too low, just reheat it." (But don't let it go above 118 °, or it will kill the yogurt.) Put yogurt in a small bowl and whisk in about 1 cup hot milk to temper it and thin it out, then whisk this back into milk in pan. Transfer milk to a container with a spout. Drain hot water from jar and add hot milk mixture. Put lid on jar. Incubate yogurt. "I wrap it in a kitchen towel so it doesn't get my blankets dirty, then set the jar in a blanket nest." Fold a small blanket or beach towel in quarters, set on a counter, and fold sides up over yogurt. Snugly tuck 2 more folded blankets around the outside. Let yogurt sit undisturbed in a draft-free place 5 hours.