At one time, spices were extremely expensive, but today the price of spices is the least expensive ingredient in any dish, and often, it is the spices that make the most significant difference in the final outcome of that dish.

Good barbecue cooks know the importance of selecting and purchasing the best spices. However, finding the best is often a problem. There are four major determining factors in selecting spices: flavor, aroma, heat and color.

Volatile oils are largely responsible for a spices' characteristic flavor and aroma, and the higher oil content, the more flavor, and the better spice.

Also, the country origin of herbs and spices, the growing conditions such as soil content, rain and heat are all factors which will give you information on the quality of a specific spice. Just like wine grapes, whose flavor differs depending on where they are gown, a spice's flavor is characteristic of the environment in which it is grown. Pepper, as well as most other spices, grows in a band within 10 to 20 degrees of the equator around the world. Pungency is the hot sensation produced in the mouth by constituents of spices such as pepper, chilies or ginger, which also contribute to flavor.

Freshness is also a critical factor in flavor and aroma – While whole spices retain their flavor fairly well, as soon as spices are ground, their flavor and aroma begin to fade, with the aroma deteriorating first. If you can’t purchase whole spices and grind them yourself, whenever possible, try to demand freshly ground spices. Fresh herbs and spices should always have a fresh, clean, distinct aroma. Heat is another determining factor when selecting a spice. This heat is measured in the spice trade in scoville units. Heat or scoville units may run from mild (1,200 units) to a very hot (6,000 units). Chilies particularly are bought often by selecting the amount of heat units. Chilies have been known to run as high as 20,000 units!

Generally, peppers and ginger are less hot and are more often described by their pungency. Peppers can be purchased that are more or less pungent, with Tellicherry pepper being the most pungent and Sarawak pepper being the least pungent.

Color is the most important characteristic of a spice or herb as far as the visual impact of a dish. Tellicherry is the blackest of the black peppers, while Brazilian black pepper is often closer to gray in color.

The color in paprika is determined by ASTA levels. The ASTA level is the amount of color that can be extracted in water. These levels run from pale (90 ASTA) to rich (140 ASTA). As you can visualize, a pale paprika would be unappealing to the eye on potato salad.

Learning how to select spices for flavor, aroma, heat and color, and how to combine flavors adds a tremendous amount to one’s cooking abilities and food presentations.