Set canning rack in large pot, place four 1-pint jars in rack, and add water to cover by 1 inch. Bring to simmer over medium-high heat, then turn off heat and cover to keep hot.

Toast anchos with reserved seeds, chile powder, coriander, and cumin in Dutch oven over medium heat, stirring frequently, until fragrant, about 1 minute.

Stir in water, onion, garlic, and salt and cook until onions and anchos are softened and water has evaporated, 7 to 9 minutes.

Stir in tomatoes and bring to simmer. Cook, stirring often, until mixture measures 10 cups, 10 to 15 minutes.

Working in batches, process mixture in blender until very smooth, about 1 minute.

Strain sauce through fine-mesh strainer into clean pot, firmly pressing solids with ladle to extract as much juice as possible; discard solids.

Return sauce to brief boil over medium-high heat, then remove from heat.

Place dish towel flat on counter. Using jar lifter, remove jars from pot, draining water back into pot.

Place jars upside down on towel and let dry for 1 minute.

Add 1½ tablespoons vinegar to each hot jar.

Using funnel and ladle, portion sauce into hot jars, leaving ½ inch headspace.

Slide wooden skewer along inside of jar to remove air bubbles.

For short-term storage: Let sauce cool to room temperature, cover, and refrigerate. (Sauce can be refrigerated for up to 3 months. Before using, simmer sauce to thicken slightly, about 10 minutes.)

For long-term storage: While jars are hot, wipe rims clean, add lids, and screw on rings until fingertip-tight; do not overtighten.

Return pot of water with canning rack to boil. Lower jars into water, cover, bring water back to boil, then start timer.

Cooking time will depend on your altitude: Boil 40 minutes for up to 1,000 feet, 45 minutes for 1,001 to 3,000 feet, 50 minutes for 3,001 to 6,000 feet, or 55 minutes for 6,001 to 8,000 feet.

Turn off heat and let jars sit in pot for 5 minutes.

Remove jars from pot and let cool for 24 hours.

Remove rings, check seal, and clean rims. (Sealed jars can be stored for up to 1 year. Before using, simmer sauce to thicken slightly, about 10 minutes.)