With the increased interest in vegetarian and vegan diets in recent times, you will find more and more recipes calling for vegetable broth instead of, or as alternative to, the more traditional meat broths.
When I make vegetable broth, I always begin with the usual aromatic vegetables that go into a classic, traditional meat-based broth: onion, carrot and celery, along with the usual spices and herbs: parsley, bay leaf, a few cloves and whole peppercorns. To this I add one or two waxy, yellow-fleshed potatoes and tomatoes, fresh ones in summer, canned out of season—or cherry tomatoes, which always seem to be available and often have better taste than other varieties.
On to this base of classic vegetables, you can now add a few vegetables in season. The beauty of a vegetable broth, like minestrone, is that it can subtly change from season to season, according to what you find the market. This week's vegetable broth included some mushrooms, some peeled baby yams and a leaf or two of Tuscan kale.
While the basic method is essentially the same as for meat-based broths, vegetable broth is, if anything, easier. You cover the ingredients with cold water, salt well and bring to a simmer, but there is no need to skim the broth (with no blood to coagulate no scum will form) and and 1-2 hours will be quite enough cooking time. To bring out full flavor, use more solid to liquid than you would for a meat broth and use an ample amount of salt.
NOTES: Vegetable broth can be used in all of the same ways as meat broths, although I find that it is particularly apt for making risotto. To my mind, it is less successful in clear soups.
You can vary the vegetables according to the season and your mood. Leeks give the broth a mellow and savory flavor. Bell peppers, if used with discretion, can add a nice zesty edge. I always like to add some leafy vegetables to a vegetable broth, but it is best to use them discreetly. Too much and the broth will take on a greenish tinge. Escarole and chicory, swiss chard are particularly flavorful. In the warmer months, vegetables like zucchini and spinach.
Some vegetables do not really lend themselves to broth. I avoid cruciferous vegetables like cauliflower, broccoli or the like, as they have an overpowering flavor that will throw the flavors out of balance. Eggplant can make the broth bitter, while fennel, I find, is a bit too sweet. Artichokes and asparagus are just too expensive to use for broth, at least for my money.
