Glass Gem corn, an heirloom variety developed by Oklahoma farmer Carl Barnes, is celebrated for its stunningly translucent, jewel-toned kernels. This unique maize is classified as a flint corn, meaning its kernels possess a hard outer shell, which is why it is not eaten fresh like sweet corn. Achieving the signature vibrant color and glassy texture requires the corn to complete its full life cycle and dry completely on the stalk, making harvest timing a precise practice. Unlike the tender, milky stage required for vegetable corn, the goal with this flint variety is maximum dehydration before the ear is removed.
Key Indicators of Maturity
The best color on Glass Gem corn develops only after the plant has dedicated its full energy to the seed, necessitating leaving the ears on the stalk long after the fresh-eating stage has passed. The most reliable indicator that the corn is ready for harvest is the condition of the protective outer husks. These husks must be completely dry, brittle to the touch, and fully transitioned to a light tan or brown color.
The silks emerging from the tip of the ear provide another visual confirmation; they should be shriveled, dark brown, and completely dry. This signifies that pollination is complete and the kernels have begun the long drying process. The corn is typically ready for harvest after the first hard frost, or approximately 100 to 120 days after planting, depending on local climate.
Once the husks and silks are dry, the final test is the hardness of the kernels themselves. Flint corn is named for its rock-hard texture, and the kernels should feel resistant to any indentation. A simple press with a fingernail should not leave a mark, indicating the moisture content has dropped low enough for the color to stabilize and the ear to be safely stored. Harvesting before this stage, while the kernels are still soft or “dented,” risks shriveled, dull kernels and potential mold issues.
Proper Harvesting Technique
When the visual cues confirm the corn is fully dry on the stalk, the physical act of harvesting must be executed carefully to prepare the ears for curing. The ear is removed from the stalk by grasping the base of the cob and giving it a sharp downward twist or snap, cleanly separating the ear at its joint.
Leave the protective outer husks attached to the ear, as these provide a natural wrapper for the initial curing phase. While some gardeners may peel back a portion of the husks to check the color, the majority should remain intact. This layer of husk offers protection against pests and helps manage the rate of moisture loss.
Since individual ears on the same stalk can mature at slightly different rates, a staggered harvest is often necessary. Only remove the ears that exhibit completely dry, brown husks and silks. Checking a few representative ears ensures maximum color development and hardness.
Post-Harvest Curing and Storage
The harvested ears must undergo a curing process to further reduce their moisture content, which prevents mold and ensures the long-term viability of the kernels. This process involves moving the ears to a dry, cool, and well-ventilated space protected from rain and pests. Good air circulation is paramount.
One common curing method is to gently peel back the husks and braid them together, creating a decorative string of corn known as a ristra. Alternatively, the husked ears can be spread out in a single layer on wire screens or drying racks, allowing air to circulate completely around each cob. The ears should be turned every few days to promote even drying.
Curing typically takes between four to six weeks, depending on the air temperature and humidity of the storage environment. The corn is considered fully cured when the kernels are so hard that they can be easily shelled off the cob by hand or with a simple twisting motion.
Storage
At this point, the moisture content is ideally around 13 to 14 percent, which is suitable for grinding into cornmeal or using as popcorn. The final, fully dried kernels can then be stored in airtight containers for years, or the cobs can be used immediately for seasonal decoration.