A hazelnut is not a peanut. Despite their common use as “nuts” in food, these two popular foods belong to entirely different plant families.
Botanical Identity
Hazelnuts are tree nuts from the Corylus genus, such as Corylus avellana. They grow on hazel trees and are harvested annually in mid-autumn. Hazelnuts are often referred to as filberts or cobnuts.
Peanuts are legumes, in the same plant family as beans, lentils, and peas. The scientific name for the cultivated peanut is Arachis hypogaea. It is grown for its edible seeds, which develop within underground pods. After fertilization, the flower’s ovary elongates into a “peg” that grows downward into the soil, where the pods mature. This underground development is unusual among legumes, leading to its species name hypogaea, meaning “under the earth.”
Allergy Considerations
Distinguishing between hazelnuts and peanuts is particularly important for individuals with food allergies, as their allergic reactions are distinct. Peanut allergies are among the most severe food allergies and can cause life-threatening reactions. They affect approximately 1.4% to 2% of people in Europe and the United States. Symptoms can range from mild, such as hives or a runny nose, to severe, including anaphylaxis, which can impair breathing and cause a dangerous drop in blood pressure.
Hazelnuts are classified as tree nuts, and tree nut allergies are also serious, but separate from peanut allergies. Hazelnut allergy is a common type of tree nut allergy, with symptoms that can include skin itching, hives, oral allergy syndrome, and in severe cases, anaphylaxis. About 0.5% to 1% of the U.S. population is estimated to have a tree nut allergy. Although peanuts are legumes, approximately 25% to 40% of individuals with a peanut allergy also react to at least one type of tree nut. Due to the potential for cross-contamination in food processing facilities, individuals with either allergy must carefully check ingredient labels.
Key Differences
Beyond their botanical classifications and allergy profiles, hazelnuts and peanuts exhibit several differences. Hazelnuts have a round shape and are encased in a hard, spherical shell. Peanuts have an oblong shape and are contained within a fibrous, often constricted pod. Hazelnuts grow above ground on trees, whereas peanuts develop uniquely underground.
Their taste profiles also differ. Hazelnuts have a rich, nutty, and slightly sweet flavor, often described as earthy or buttery. Peanuts possess a more distinct, earthy, and often savory taste. Nutritionally, both are calorie-dense, but peanuts provide more protein per 100 grams than hazelnuts, while hazelnuts have higher amounts of certain minerals like iron and potassium.