The almond, a widely consumed food, often causes confusion regarding its botanical classification. Many people assume it is a true nut, but the almond is actually the seed of a fruit that develops on a tree. Understanding the almond’s origin clarifies why it is not considered a traditional nut and explains the necessary steps to prepare it for market.
The Botanical Identity of the Almond
The almond is the seed of a fruit produced by the tree species Prunus dulcis. This tree belongs to the Rosaceae family, the same botanical family as roses, apples, and strawberries. The almond fruit is classified as a drupe, a type of fruit characterized by a fleshy exterior and a single, hard pit or “stone” in the center.
Familiar drupes include peaches, cherries, and plums. However, the almond fruit develops differently than these other stone fruits. While the outer flesh of peaches and plums is consumed, the almond fruit’s exterior is leathery and not eaten. The valuable commercial product is the seed found inside the pit, making the almond unique among its relatives.
Anatomy of the Almond Fruit
The almond fruit consists of three distinct layers protecting the final edible part. The outermost layer is the hull, a thick, grayish-green, and somewhat velvety covering. This hull represents the outer and middle layers of the fruit wall.
As the fruit matures, this leathery hull naturally dries out and begins to split open along a seam, a process called dehiscence. Beneath the hull is the hard shell, which is the lignified endocarp of the fruit. This shell serves as a rigid, protective barrier for the inner seed.
Inside the woody shell is the edible portion, the seed, commonly referred to as the kernel. The seed is covered by a thin, brown seed coat, also known as the pellicle or skin.
Harvesting and Processing
The commercial process begins when the fruit is fully mature and the hull has naturally split open on the tree. Most modern harvesting is done mechanically, using a machine that shakes the tree trunk or branches. This action causes the mature, dried fruit to fall onto the orchard floor.
The fallen almonds, still encased in their hulls and shells, are left on the ground to dry further in the sun for about seven to ten days. Mechanical sweepers then gather the almonds into rows, and a harvester machine collects them for transport.
The first major step at the processing facility is hulling, which removes the soft, inedible outer hull. Following hulling, the almonds are shelled to remove the hard, woody inner layer. This is done by passing the in-shell almonds through rollers or cylinders that crack the shell without damaging the kernel. The clean, edible kernel is then separated from the broken shell fragments and readied for packaging.