Things You'll Need
About 3 or 4 cups of roughly chopped vegetables, including any mix of carrots, celery, fennel, potatoes, greens such as kale, chard or spinach, zucchini or squash, cabbage, broccoli, mushrooms, bell peppers, asparagus, etc.
1 whole onion
2 to 4 cloves of garlic, per taste
Whole fresh herbs, including any of the following: rosemary, marjoram, basil, thyme, oregano, bay leaves
Salt and pepper to taste
Large pot or Dutch oven
Water to cover the vegetables in the pot
It's easy to make vegetable broth or stock at home and store it in the freezer for later use. Making homemade vegetable broth is a great way to use leftover vegetables, veggies that are about to go bad or stems and end pieces that you would otherwise just toss out.
Gather your ingredients. You can make vegetable broth from just about anything you have in your kitchen. A standard combination of carrots, celery, onion and garlic with herbs will give you a basic flavorful broth, but adding other vegetables will add other nutrients and flavors. You can experiment with different combinations of vegetables depending on what you have in your kitchen to create different flavors of veggie broth.
Chop all of the vegetables coarsely so that everything will fit into the pot. There's no need to chop everything into small pieces, as you would for soup, because you will be discarding most of the vegetables once the broth has cooked down.
Prepare the herbs. If you have fresh herbs on hand, they are always recommended over the store-bought, dried versions simply because they are more flavorful. Use any combination of the following to flavor your broth: rosemary, marjoram, basil, thyme, oregano or bay leaves. If using fresh herbs, coarsely chop about a tablespoon of each, except for the bay, for which you only need one leaf. For dry herbs, reduce to about a teaspoon of each.
Place all of your coarsely chopped vegetables and herbs in the pot, then cover with water. Turn the heat on high and bring to a boil, then reduce the heat to a simmer. Add salt and pepper to taste.
Simmer the broth for 1.5 to 2 hours. Taste occasionally and add more salt and pepper if needed.
Turn the heat off after the broth is finished and let it cool for a while. Strain through a colander and discard vegetable pieces. The broth can be kept in the refrigerator overnight, but if you're not using it immediately, it should be frozen. Pour the finished broth into freezer-safe containers and once it has cooled completely, freeze until needed. You can use your broth as a base for soups or as the liquid that you cook potatoes or pasta in, to add more flavor.
You can save unused vegetable ends or cuttings throughout the week in an airtight container in the fridge to make a stock once you've collected enough.