Split pea soup exists in multiple cultures and can be mildly flavored or very spicy. The standard Western version is on the mild side, but some recipes will include spices and other flavorful ingredients. Here are some of the best spices for split pea soup:
Olive oil
Even though it is technically not a seasoning, olive oil does a lot for the flavor and mouthfeel of split pea soup. Ideally, you will want to use extra virgin olive oil. It will complement the complexity of the soup’s flavor profile with its bright and grassy taste.
The addition of healthy fat will make the soup richer and help balance the use of pork, which is essential in many split pea soup recipes.
Pork
You will see cured pork used in most traditional split pea soup recipes in one form or another. Common forms include bacon, ham, and ham hocks.
Any of the various cured pork options will add a rich and unctuous mouthfeel to the soup, along with a delicate smokiness and intense umami. In most cases, the pork will also provide a significant amount of the recipe’s salt.
Garlic
Garlic is one of the world’s most popular seasonings but is not always necessary in this dish. You won’t see garlic in many old-fashioned split pea soup recipes even though it goes with all of the other traditional ingredients.
Garlic is an essential seasoning in newer vegan split pea soups where its umami qualities and earthy intensity do a good job of replacing pork products.
Onion
Onion is a member of the Allium family that contains a set of flavors that is essential to brothy and braised dishes like soups and stews. Depending on how they are used, onions can contribute to a strong umami background note, or they can provide a nutty sweetness or both.
Split pea soup recipes may call for regular yellow onions, or you can use green onions if you want a more intense flavor. Vegan soups can benefit from the intensity of green onions as they can help to compensate for the missing pork. Some recipes will call for chives to add a more subtle and grassy version of the onion flavor.
Celery
Classified as an aromatic, celery is another essential soup herb that helps to give brothy notes to dishes like split pea soup. Its flavor profile is savory and herbaceous. Many split pea soup recipes begin with celery and onions being sauteed at the start to lay down a flavorful base for the rest of the soup.
Thyme
One of the many culinary herbs in the mint family, thyme is a traditional split pea soup ingredient that contributes a woodsy and camphoraceous flavor profile that can enhance the other spices. It is a mildly bitter savory herb that works about as well dry as it does fresh in split pea soup.
Both dried and fresh forms should be used sparingly since thyme can quickly take over the flavor profile of the soup if you use too much.
Black pepper
Fresh ground black pepper is an essential addition to split pea soup just as it is to many savory recipes. Black pepper is the lone source of heat in most split pea soup recipes.
The fresh ground variety adds a mild lemony note and other complex flavors that you won’t get from the pre-ground variety though pre-ground black pepper will still give you a little of the heat.