Step 1

In a Dutch oven, heat milk over medium heat until a thermometer reads 200°, stirring occasionally to prevent milk from scorching. Remove from heat; let stand until a thermometer reads 112°-115°, stirring occasionally. (If desired, place pan in an ice-water bath for faster cooling.)

Step 2

Whisk 1 cup warm milk into yogurt until smooth; return all to pan, stirring gently. Stir in lemon zest and coriander. Transfer mixture to warm, clean jars, such as 1-quart canning jars.

Step 3

Cover jars; place in oven, turn on oven light to keep mixture warm, about 110°. Let stand, undisturbed, 6-24 hours or until yogurt is set, tilting jars gently to check. (Yogurt will become thicker and more tangy as it stands.)

Step 4

Cover; refrigerate until cold. Store in refrigerator up to 2 weeks. If desired, serve with honey.