Quinoa is a pseudocereal, a plant that produces seeds and is consumed like a grain, and has been a staple crop in the Andes Mountains for thousands of years. Successfully harvesting this nutritious food requires attention to timing and methodical post-harvest processing. A successful harvest ensures the seeds are fully developed, clean, and properly prepared for long-term storage.
Recognizing When Quinoa is Ready
Determining the precise moment to harvest quinoa is the most important factor for maximizing yield and quality. The most reliable indicator is a significant change in the plant’s foliage. The lower leaves will begin to dry out, turn yellow, and drop off the stalk entirely. This leaf drop signals that the plant has shifted its energy to seed maturation, typically occurring around 90 to 120 days after planting. The large, dense seed heads, or panicles, will also change color, transitioning from green to the mature color characteristic of the variety (yellow, red, or deep purple).
The definitive test for readiness involves checking the hardness of the individual seeds. Select a few seeds and press them firmly between your fingernails. If the seed is fully mature, it will be hard and will not yield or dent under pressure. Harvesting too early results in shriveled seeds, while waiting too long increases the risk of seeds shattering and falling, especially due to wind or rain.
Harvesting the Stalks and Curing
Harvesting involves cutting the entire stalk when the plant is mostly dry but before the seeds become loose enough to shatter. Use sharp shears or clippers to cut the stalks just below the seed head, or near the base if curing the entire plant. Cut on a dry day to minimize moisture content. The goal is to collect the seed heads intact and complete the drying process in a protected environment, preventing losses to weather or birds.
After cutting, the stalks must undergo a curing period to ensure the seeds are completely dry and moisture is released. Gather the stalks into small bundles and hang them upside down in a sheltered, dry space, such as a garage or barn. This space needs good air circulation to facilitate drying and prevent mold growth. Placing a tarp beneath the hanging bundles is advisable, as some dried seeds may drop during curing.
Separating Seed from Chaff
Once the stalks are fully cured and brittle, the next step is threshing: physically separating the seed from the dried flower head and stalk material. For the home grower, a common method involves placing the dried heads inside a large container, such as a trash can or canvas bag. Rub the heads vigorously with gloved hands or strike the container against a hard surface. This action breaks the seeds free from the surrounding plant debris. The resulting mixture contains quinoa seeds along with stems, leaves, and papery flower parts, collectively known as chaff.
The second mechanical step, winnowing, uses air movement to separate the lighter chaff from the heavier seeds. Winnowing can be done outdoors on a breezy day by slowly pouring the seed and chaff mixture from one container to another, allowing the wind to carry the chaff away. For a controlled indoor method, position a box fan to create a steady, gentle air current. Slowly pour the mixture in front of the fan; the heavy seeds fall straight down into a collection vessel while the fan blows the chaff aside. Repeat this process until the remaining material is primarily clean quinoa seeds.
Removing Saponins and Final Storage Preparation
The harvested quinoa seeds possess saponins, a bitter, soap-like compound concentrated in the seed’s outer layer. This coating must be removed before consumption to eliminate the bitter taste. The process involves thoroughly rinsing the seeds under cold, running water, typically using a fine-mesh sieve or bowl. The saponin content creates a noticeable foam during the initial rinses.
Continue rinsing and agitating the seeds frequently until the water runs completely clear and no foam is visible. Since the seeds are saturated with moisture after washing, a final drying step is mandatory for safe, long-term storage. Spread the cleaned, wet quinoa in a thin layer on a clean cloth or baking sheet and leave it to air dry completely in a well-ventilated area. This final drying is essential because any residual moisture will lead to mold growth and spoilage. Once the seeds are dry, they can be stored in an airtight container in a cool, dark place.