Vegetable Stocks

A vegetable stock is a water extract of several vegetables and herbs that can serve as a flavorful base for soups, sauces, and other preparations. By simmering the vegetables until soft, the cook breaks down their cell walls and releases the cell contents into the water. These contents include salts, sugars, acids, and savory amino acids, as well as aromatic molecules. Carrots, celery, and onions are almost always included for their aromatics, and mushrooms and tomatoes are the richest source of savory amino acids. The vegetables are finely chopped to maximize their surface area for extraction. Pre-cooking some or all of the vegetables in a small amount of fat or oil has two advantages: it adds new flavors, and the fat it contributes is a better solvent than water for many aromatic molecules. It’s important not to dilute the extracted flavors in too much water; good proportions by weight (volume varies by piece size) are 1 part vegetables to 1.5 or 2 parts water. The vegetables and water are simmered uncovered (to allow evaporation and concentration) for no more than an hour, after which it’s generally agreed that the stock flavor ceases to improve and even deteriorates. Once the vegetables are strained out, the stock can be concentrated by boiling it down.