Vegetable Broth (Crock Pot/Slow Cooker)

I make this at least once a month, sometimes more often. Please feel free to review my recipe! I really wonder how much salt to add. There is no method to my technique; this is how the recipe has evolved and I really enjoy it. I use two crock pots, so please change serving size if necessary. This recipe makes 20 cups.

• Ready In: 9 hrs 45 mins
• Serves: 20
• Yields: 20 cups

Ingredients

• 180  ounces water
• 2  tablespoons olive oil
• 2  large  vidalia onions, diced
• 1  large  white onion, diced
• 3  small leeks, sliced
• 3  celery ribs, sliced
• 3  carrots, sliced, divided
• 4  minced garlic cloves
• 1⁄2 teaspoon salt
• 2  tablespoons celery leaves
• 2  tablespoons  McCormick's salt-free all-purpose seasoning
• 1  teaspoon ground pepper
• 1⁄4 cup vermouth
• 3  parsnips, diced
• 1  green pepper, diced
• 1  yellow pepper, diced
• 2  small zucchini, sliced thin
• 1⁄2 cup parsley, chopped
• 1 (15 ounce) can diced tomatoes
• 3  tablespoons tomato paste
• 3  bay leaves

Directions

1. Slice leeks lengthwise and cut into 1/2" slices. Rinse in cold water and separate layers to remove any dirt or debris. Spin dry if possible or dab with paper towel.
2. Dice onions and slice celery and carrots reserving 1/2 cup carrots.
3. Heat 2 TBSP olive oil over medium heat in Dutch oven and add onions, leeks, celery, carrots, and 4 cloves minced garlic. Sprinkle 1/2 tsp salt on vegetables to induce sweating, and stir occasionally for 10 minutes. **Add seasoning, pepper and celery leaves after 5 minutes.
4. After 10 minutes, increase heat and add 1/4 cup dry Vermouth to pot. Stir until evaporated. Remove from heat.
5. Add reserved carrots to the pot, chopped parsnips, peppers, zucchini, parsley, and can of tomatoes with juice. Stir to blend well.
6. Divide vegetables between large and small crock pots.
7. Add two tbsp tomato paste and two bay leaves to large crock and one tbsp tomato paste and 1 bay leaf to small crock pot.
8. Fill pots with approx 180 ounces or 1.5 gallons of water.
9. Cook on low for 8-10 hours.
10. I strain through cheesecloth and freeze in 1 cup servings. I use it in almost everything!