Cilantro (Coriandrum sativum) is a versatile annual herb cultivated for its fresh leaves, but it also produces flavorful seeds known as coriander. These seeds offer a warm, citrusy flavor distinctly different from the foliage and can be saved for culinary use or replanting. Harvesting and preserving these seeds requires patience and precise timing to ensure high quality and viability.
Understanding the Plant’s Transformation
The initial step in seed saving is allowing the cilantro plant to undergo bolting. This natural transition occurs when the plant is exposed to rising temperatures or lengthening daylight hours. Bolting signals the end of the plant’s leaf production phase, as it shifts its energy toward reproduction.
The plant sends up tall, sparse flower stalks from the center of the leafy rosette. These stalks produce delicate clusters of white or sometimes pink flowers, which are attractive to pollinators. Once the flowers fade, small, round, green seed pods begin to form, which are the immature coriander seeds.
It is important to resist the urge to harvest at this green stage, as the seeds have not fully matured. The seed heads must be allowed to ripen on the plant, gradually changing color from green to a light tan or brown. Waiting until the majority of the seeds are dry and hard to the touch is necessary for them to develop their full flavor and maintain viability for future planting.
Harvesting the Seed Stems
Timing is delicate when harvesting the stems, as waiting too long can result in the seeds shattering and dropping to the ground. The ideal moment to cut the stems is when most seeds have turned light brown, but before all of them have dropped. Harvest in the early morning when moisture helps keep the seeds from scattering easily.
Using sharp shears, cut the entire seed stalk, leaving a few inches of stem attached to the seed heads. Hold a container or cloth beneath the umbels as you cut to catch any loose seeds. Collecting the seeds before they are completely dry on the plant helps prevent significant loss due to wind or accidental disturbance.
The cut stems must be moved to a cool, dry, and well-ventilated indoor location to finish curing. Tying the stems together in loose bundles and hanging them upside down is an effective method. Placing a large paper bag loosely secured around the hanging bundles will catch any seeds that naturally drop as they finish drying over the next one to two weeks. This step ensures that any remaining green seeds fully mature off the main plant, concentrating their flavor and maximizing their hardiness.
Cleaning, Curing, and Storing the Seeds
Once the stems and seed heads are brittle and completely dry, the seeds must be separated from the chaff, a process known as threshing. Gently rubbing the dried seed heads between your hands or against a coarse screen will easily release the hard, round seeds, breaking them free from the dry floral material.
The resulting mixture of seeds and debris needs to be cleaned through winnowing or sifting. Using a kitchen strainer or a fine-mesh sieve helps separate the seeds from smaller plant matter. For a more complete clean, pour the mixture from one container to another in front of a light breeze or fan; this carries away the lighter chaff while the heavy seeds fall straight down.
It is important to ensure the seeds are fully cured and contain no residual moisture before being stored, as dampness can lead to mold and ruin the entire batch. Once completely dry, the seeds should be placed in an airtight container, such as a glass jar or a sealed plastic bag. Store the container in a cool, dark, and dry location to maintain their potency for cooking and their viability for planting.