An herb sachet is a packet of herbs which are cooked along with a dish, lending a burst of herbal flavor. Many dishes call for the use of an herb sachet, and the formulations of herbs in an herb sachet can vary widely, depending on what is being cooked. In French cuisine, an herb sachet is called a bouquet garni, a “garnished bouquet.” Soups, stocks, stews, and long simmering dishes often incorporate herb sachets.
There are several reasons to use an herb sachet, rather than simply tossing herbs and seasonings into the water as the dish cooks. The first is that an herb sachet is neat, since it can be pulled out when the dish is finished. Diners will not encounter slimy, heavily stewed herbs in their food, or choke on small twigs and trimmings. In addition, the level of seasoning can be easily controlled by pulling an herb sachet out or putting it back in. Also, an herb sachet saves time, since the cook does not have to carefully trim and cut herbs, and the use of stems and twigs creates a more complex flavor.
There are a number of ways to create an herb sachet. In the case of a bouquet garni, whole stems of herbs are often tightly bundled together and tied up with string. In other instances, herbs can be bound up in a piece of cheesecloth, which will slowly release the flavor without letting the herbs out. When using cheesecloth to make an herb sachet, make sure that it is tightly tied. Some cooks also use infusion balls or tea balls, since they snap shut very effectively.
You can also use an herb ball, a device designed specifically for creating an herb sachet. An herb ball may be larger than a tea ball, allowing it to accommodate more seasonings, and it usually has a long handle or chain for easy retrieval. The larger size also ensures that the herbs infuse fully, since tightly packed herbs will not yield as much flavor as loose ones.
Cooks can use any herb or combination of herbs they like in an herb sachet. Some common choices include sage, dill, oregano, parsley, tarragon, chives, sage, leek, chervil, savory, marjoram, rosemary, basil, celery, coriander, and even vegetables like onions and carrots. Lightly crushing the herbs first is advised, as this will help free the flavorful natural oils, lending more flavor to the finished dish. Fresh or dried herbs may be used, depending on availability and personal taste.