As you know, timing is everything when preparing a meal. The same is true for the spice, i.e. when you season has an effect on the intensity of the flavor. Depending on the spice, cooking can increase potency, as you may have discovered when adding cayenne pepper to your simmering spaghetti sauce. Or the flavor may not be as strong as you thought it would be. This is particularly evident when adding herbs that are cooked for a long period of time, either in a sauce or slowly cooked in a crock pot.
Flavorings can be tricky when they come into contact with heat. Heat enhances and destroys flavors, because heat allows essential oils to escape. The beauty of a crock pot is that slow cooking allows for the best results when using spices in a meal. The covered pot prevents moisture and steaming flavors and oils from escaping, and allows the spices to permeate the food in the pot. Using a microwave, on the other hand, may not allow flavor to be released, especially in some herbs.
Common sense tells us that baking spices such as allspice, anise, cardamom, cinnamon, cloves, ginger, mace, nutmeg, and mint can be added at the beginning of cooking. They all stand up to short and long-term baking, whether it’s for a batch of cookies or a sheet cake. They also work well in sauces that need to simmer, although nutmeg is often stirred over an item after serving. Cinnamon, as well as rosemary, will wreak havoc on those using recipes with yeast and both are considered yeast inhibitors. Caraway seed tends to become bitter with prolonged cooking and turmeric can become bitter if burned.
Most herbs tend to be a bit more finicky when it comes to cooking. Their flavors seem to cook into a sauce much faster. Herbs include basil, chervil, chives, cilantro, cilantro, dill (seeds can withstand cooking longer than leaves), lemongrass, parsley (flat or Italian leaf is best for cooking), sage, tarragon, and marjoram . In fact, marjoram is often sprinkled on top of a soup after serving and is not cooked at all.
The exception to these herbs is the hardy bay leaf, which holds up very well in a crock pot or stew. The oregano can be added at the beginning of cooking (if cooking less than an hour) and so can the thyme. Often the sustainability of an herb’s flavor has as much to do with the temperature at which it is cooked as it does with the length of time it is cooked.
Onions and their relatives can withstand prolonged simmering at low temperatures, but are best added toward the end of cooking. Leeks are the exception. Garlic can become bitter if overcooked. The softer shallot will hold up just fine, but will turn bitter if browned.
Peppercorns and hot peppers are best added last, as they become more potent as they cook. This includes chili powder and Szechuan peppers. Here paprika is the exception and can be added at the beginning of cooking. Mustard is often added at the end of cooking and is best if not boiled.
Sometimes not cooking has an effect on the flavor. Many of the herbs listed above are used in salads. Cold, raw foods like potato salad or cucumbers can soak up the flavor, so be more generous with seasonings and add them earlier in the preparation. Freezing foods can destroy flavors completely, so you may need to re-season them after reheating.
Again, much of the cooking process depends on how long and how hot you cook the food. It also has a lot to do with how you like your food to taste. My Midwestern relatives can’t handle hot peppers like us Southwesterners, and I can’t use cayenne pepper in their presence. As you can see, seasoning is not objective, nor is it an exact science. But that shouldn’t stop you from playing mad scientist and delving into hands-on experimentation.
