The Science of Herbs & Spices
"If variety is the spice of life, marriage is the big can of leftover Spam." Johnny Carson
Meats and veggies often taste great unadorned. A great ribeye steak or a filet of fresh Chilean Sea Bass need nothing more than a little salt and pepper. But chefs make their living by amping foods up with herbs, spices, and sauces with herbs and spices in them. Here are some things to know about these important flavor enhancers and a list of what well armed cooks will have in their tool kits.
What are spices? Spices are flavorings made from seeds, berries, fruits, bark, and roots.
What are herbs? Culinary herbs are flavorings for cooking usually made from green leaves (that's a sage leaf at the top of the page). Medicinal herbs include things cooks call spices.
Fresh vs. dried herbs. Herbs are wonderful and fresh herbs are more wonderful. The taste of freesh herbs is significantly different than their dried counterparts. Fresh herbs are about 80% water so dried herbs are almost an entirely different animal. Some herbs change more than others when dried. Dried rosemary is a lot like fresh rosemary, but dried dill bears no resemblance to fresh. That's because most of the flavor in rosemary comes from the oils in the leaves while dill has much less oil.
When herbs like oregano and basil are dried, they are usually crushed which also allows fragrance and flavor to flee. Other herbs, like rosemary and bay leaf, are not crushed when dried. Of course you can crush or powder them if you wish. I love powdered bay leaf in some of my rubs. You just can't find them in the store, so I take them for a spin in my spice grinder.
Fresh herbs can add an element of complex and bright flavor to whatever you are cooking. A pinch of rosemary in grits can make them really pop. Fresh basil and tomato are made for each other like peanut butter and jelly. Fresh herbs are really worth the effort to grow. They take up little space, and many can be grown in pots and on window sills. Windowbox.com is a good source for supplies for growing herbs indoors.
In cooking, fresh herbs are usually added just before serving, cooking for only 30 to 60 seconds, in order to preserve their freshness.
This is important. Herbs and spices that are grown outdoors are susceptible to bird droppings, mice, rabbits, etc. Unless they are irradiated, they need to be cooked to be made safe.
2 parts fresh herbs = 1 part dried. Approximately. Sometimes. It's a good rule of thumb, but not perfect. Some say 3 to 1. It depends heavily on how fine the herbs have been crushed and how fresh they are. Powdered bay leaf packs a bigger whallop than crushed bay leaf, which is more potent than whole bay leaf.
Drying herbs can concentrate some of their flavors, while other flavors evaporate. Swapping fresh for dried can have a major impact on the recipe. So you should always try to use what the recipe calls for. That said, here are some guidelines for substituting dried herbs if you can't get a fresh herb.
For something like pesto, which is a pasty sauce made with lots of fresh basil, you cannot substitute dried for fresh.
When to use them. We use fresh and dried herbs differently, too. The flavors in fresh herbs are delicate and ephemeral, so they are usually added with about 5 minutes or less left in the cooking process. Chopping them makes them give up their flavors more easily. Dried herbs should be crumbled and need to be added earlier to extract their flavors.
Storing fresh herbs. It is important to keep fresh herbs cool and moist. The best method is to put their stems in a vase of water in the fridge, but that's not very efficient spacewise. Another technique is to wrap them in moist paper towels and pur that in a plastic bag that has some holes to allow it to breathe so they don't get moldy.
Storing dried herbs and spices. Dried spices and herbs deteriorate with age, light, heat, moisture, and oxygen, and there can be a major difference in quality between a new bottle of basil and an old one. For that reason it makes sense to buy them in small bottles. My favorite spice merchant, Penzeys.com, sells many in half-bottle sizes holding about one ounce.
If you buy herbs and spices in plastic bags, put them in bottles. Air can penetrate bags. Twist the caps on tightly. Mark the date of purchase on the bottle. Store spices in cool, dark cabinets.
Fresh green herbs can usually be frozen. Dried green herbs age more quickly than ground spices. Toss them after a year. Toss ground spices after two years. Whole spices keep longer still. They get the heave-ho after three years. But these are just guidelines. Notice the color when you buy herbs and spices. Most are bright and vibrant. When they get dull and flat, toss them. Notice the smell when you buy them. Rub some in the palm of your hand and smell. If it is not strong and distinctive, out the door it goes. If they clump and cake so much you need an ice pick, sayonara. Tossing old herbs and spices can get expensive. If you must use an old herb or spice, just increase the quantities by about 25 to 50%, and taste the dish frequently. I often toss them on the coals of my grill for a little extra exotic smoke flavor, especially for fish and chicken.
Caking. To keep them from caking, pour spices into a measuring spoon or your palm. Don't pour them directly into a hot pot because steam can get in when the spices get out.
Seasoned salts. Don't use seasoned salts such as garlic salt or celery salt in cooking. Use garlic powder or celery seed powder. This way you can better control the salt content. Seasoned salts are sometimes nice to use on the dinner table. Make your own blend by blending 1/2 cup of sea salt with a tablespoon of mixed herbs and spices. Here's my favorite seasoned salt recipe.
Using herbs and spices
The flavors in herbs and spices are usually locked in and need to be dissolved to produce their a taste. Sometimes they are dissolved in our saliva, but more frequently they are dissolved in food by one of three common solvents: Water, alcohol, or fats. Usually heat accelerates dissolution.
The flavor of many herbs and spices is in their oils and can best be released by putting them in oil. Heating the oil really accelerates extraction. It is not uncommon to start cooking by warming oil in a pan, adding onions until they wilt and sweeten in a few minutes, adding presssed garlic until it gives up its pungence in less than a minute, and then adding spices and dried herbs to extract their oils for about a minuter. The flavors spread throughout the oil and are then spread through the rest of the ingredients as they are added. The cooking process often ends by tossing in fresh herbs just before serving, just to warm them.
Oils can also be extracted and magnified by "blooming" ground spices in a dry warm, frying pan for a minute or two until they get aromatic. They can then be added to other ingredients.
Some herbs and spices can be packed in oil to extract their flavors, but this is too risky to do at home. The process easily produces Clostridium botulinum which can kill you of botulism.
It is always a good idea to cook spices and herbs before serving them, even ground pepper. They grow outdoors where they are exposed to birds, rodents, and other furry creatures that can contaminate them. FDA testing has found contamination in many spices and herbs, especially salmonella. Cooking, even for a minute or two, can be enough to kill pathogens.
Marinades. In most cases dried herbs and spices are better in marinades than fresh because thy are more potent and dissolve more easily.
Beware of "sprigs". Some recipes call for a sprig or rosemary or another herb. In general these are dangerous recipes unless they specify low long the sprig is or how much it should weigh. Rosemary, for example, can grow long sprigs, and the leaves can range from 1/4" to more than 1". Depending on the size of the sprig you choose, you could be adding perhaps three times as much flavoring as necessary.
Grind and sift your black pepper. If you use black pepper, it is always better to grind your own with a pepper mill. Freshly ground black pepper has more more pepper flavor, more bite, and more heat than the pre-ground stuff. If you use ground pepper on steaks or other things you are grilling hot, grind your pepper and sift it through a mesh strainer. Save the powder for something else, like your homemade barbecue sauce, and use the big chunks on the steak. Sprinkle them on and press them in with your hands.
The outdoor cook's pantry
There are lots of other great ways to bring flavor and complexcity to your dishes. You need hot stuff, tart stuff, oils, and dairy. Below is a list of what you need for a well-stocked pantry.
If you buy a good spice grinder you can get a lot of herbs and spices whole and grind them as needed. Whole seeds keep longer, taste better when ground fresh, and free up a lot of space in your kitchen. Get a coffee grinder for reducing peppecorns to crushed pepper, or for powdering celery seeds, anise, caraway, bay leaves, etc. Get one with a blade not burrs, and make sure it is easy to clean if you plan to use it for both coffee and spices ("Honey, why does the coffee make me cry today?"). I like the Krups GX4100 Electric Coffee and Spice Grinder.And while you're at it, get a garlic press. Makes quick work of smashing up garlic.
Essential dried herbs
Bay (laurel) leaf
Essential fresh herbs
Most of these will grow well on a well-lit window sill
Essential hot stuff
Peppercorns in a grinder, black
Bread crumbs, plain
Jams, especially seedless black raspberry
Orange juice concentrate
Lemon juice, fresh
Lemon juice, bottled
Lime juice, fresh
Orange juice, bottled
Essential fats & oils
Bell pepper, green
Bell pepper, red
Tomatoes, fresh plum
Cheddar, sharp yellow
Swiss or Jarlsberg
Milk, at least 2% fat
Coffee, whole bean
Tomatoes, canned whole
Optional dried herbs
Optional fresh herbs
Other useful stuff
Ghee (clarified butter)
Grand Marnier Liqueur
Substituting one herb or spice for another
Whenever possible, you should use the hers and spices in the recipe. But many are similar in taste so if you are out of one you can use another. By trading one herb for another you will be significantly changing the taste of the dish. Also, some herbs are stronger than others. For example, you can use basil in place of cilantro, but cilantro is stronger. You should also remember that powders are stronger than crumbled herbs and spices because they are more compact with less air, so ground cayenne will be stronger than crumbled cayenne.
It is always better to make a quick run to the grocer or knock on your neighbor's door if you lack an ingredient, but making one of these substitutions will usually work. The dish will be good, but different. The farther to the right you go the further you get from the taste of the one on the left.
My favorite cooking tools
Click here to see a buying guide to more of my favorite cooking tools and a discussion of why I like them.