What Are the Differences Between Herbs and Spices?

A herb is a whole or part of plant that is used to flavor food. This is usually the softer stems or leaves of plants and can be whole, ground, fresh, or dried.

A spice is a substance that is used to flavor food and is derived from a dried plant and usually a seed, bark, or root part and is normally ground and powdered; although in some cases they may be whole seeds.

Dried herbs are best used in recipes where there is plenty of time for them to cook in as they need enough time soak up some of the water to rehydrate. They first need to regain some of the water before releasing their essential oil and flavor compounds.

Herbs such as oregano, thyme, parsley, rosemary, and sage should be added towards the beginning of a cook so there is time to extract the oils which allow the flavors to fully develop.

Delicate varieties such marjoram, dill, and basil should be added closer to the end as their flavoring and oils will evaporate and leave a mild off-taste.

Over cooking all herbs and spices will lead to a loss of flavor and they should be added towards the end of slow cooking or long and slow braising.

If substituting dried for fresh herbs, you should start out with around 1/2 of the amount called for in the recipes. If this is not enough, you can always add more but it's fairly difficult to recover if you have added too much.