Lemon balm, known scientifically as Melissa officinalis, is a perennial herb belonging to the mint family, Lamiaceae. It is valued for its distinct lemon fragrance and traditional use in calming preparations, especially as a tea. The plant’s aromatic qualities are due to volatile oils, such as citronellal. Proper harvesting and drying techniques preserve these oils, ensuring the herb retains its flavor and therapeutic properties when steeped for tea.
Optimal Timing for Harvesting
The ideal time to harvest lemon balm to maximize its flavor and potency is just before the plant begins to flower, typically in late spring or early summer. At this stage, the concentration of volatile oils in the leaves is at its highest. Allowing the plant to flower diverts energy away from leaf production, resulting in a reduction in the leaves’ essential oil content and flavor.
The time of day for harvesting also influences the quality of the final dried product. It is recommended to cut the stems in the mid-morning, after the morning dew has fully evaporated from the leaves. This timing ensures the leaves are dry, preventing browning, and avoids the peak heat of the day, which can cause volatile oils to dissipate. Lemon balm is a vigorous grower, allowing for multiple harvests throughout the growing season, often one to three heavy cuttings.
Harvesting Techniques and Preparation
When preparing for a large harvest intended for drying, use a sharp, clean tool such as scissors or pruning shears to make precise cuts. Sharp tools prevent crushing the stems, which can damage the plant and hinder its recovery. The goal is to encourage new growth for future harvests. This is achieved by cutting the stems just above a leaf node or a set of leaves.
Cut the plant down to within six to eight inches of the soil level, but never remove more than two-thirds of the plant’s vegetative growth. Leaving at least one-third of the plant intact supports healthy regrowth and prevents undue stress. After cutting, inspect the harvested material and remove any blemished leaves or debris. If the leaves are dusty, rinse them gently in cool water, shake off excess moisture, and lay the stems on a clean cloth to surface-dry before preservation.
Drying and Curing Methods
Proper drying is necessary to preserve the lemon balm’s volatile oils and prevent mold formation for long-term storage. The leaves must be completely dry and brittle before storage, as any residual moisture leads to spoilage. Air drying is a popular method, involving gathering small bundles of four to six stems and tying them loosely with twine. Hang these bundles upside down in a clean, dry, dark location with good air circulation.
Air Drying Conditions
The drying space should be relatively cool, ideally below 85°F. The time required can range from one to three weeks, depending on the humidity.
Dehydrator Drying
Alternatively, a food dehydrator offers a faster, more controlled method. Spread the leaves in a single layer on the trays and dry them at the lowest temperature setting, generally between 95°F and 105°F. Drying takes between 12 to 18 hours, and the leaves are ready when they feel crisp and crumble easily.
Storage
Once fully dried, strip the leaves from the stems and store them whole to best retain flavor and potency. Place the final dried product in an airtight container, such as a glass jar, and keep it in a dark, cool place away from direct sunlight.