Thyme provides an earthy, slightly floral flavor to many culinary dishes. Drying the harvest allows for year-round enjoyment of this herb. The quality of the final dried product depends on harvesting the plant when its volatile compounds are most concentrated. Correct timing and careful preparation ensure dried thyme retains maximum flavor and potency.
Optimal Timing for Peak Flavor
The most potent flavor comes from harvesting the stems just before the plant begins to flower, typically in late spring or early summer. At this developmental stage, the plant redirects energy into leaf growth, leading to the highest concentration of essential oils, such as thymol. Once small purple or pink blossoms appear, the plant’s energy shifts to reproduction, which reduces the oil content and flavor intensity in the leaves.
The time of day also plays a role in maximizing the essential oil content. Harvesting should ideally take place in the mid-morning, after the morning dew has completely evaporated. This ensures the leaves are dry, preventing potential mold during drying. It also captures the oils at their peak concentration before the midday sun causes them to evaporate.
Maximizing Yield with Proper Cutting
Harvesting must be performed with clean, sharp tools, such as scissors or pruning shears, to ensure a clean cut that promotes rapid healing and regrowth. For a major harvest intended for drying, only trim the soft, green growth and avoid cutting into the woody, older base of the plant. Cutting woody stems is detrimental to the plant’s long-term health because they do not regenerate well.
To encourage a healthy, bushy plant, make cuts just above a leaf node, which is the small bump where a pair of leaves meets the stem. Leave at least one-third of the plant intact, ensuring 4 to 6 inches of green growth remains. This practice allows the plant to continue photosynthesis and recover quickly for subsequent harvests, which can be done two to three times annually.
Preparing and Drying Methods
Preparation
Immediately after cutting, prepare the stems for drying without washing, as residual moisture encourages mold. If the stems are dusty, a gentle shake is sufficient. If rinsing is necessary, the sprigs must be patted and air-dried completely before proceeding. Bundle the stems into small groups of five to six sprigs and secure them loosely with twine or a rubber band at the base.
Air Drying
Air drying is the simplest preservation method. Hang the bundles upside down in a location that is warm, dry, and well-ventilated. The drying space must be dark, since direct sunlight degrades essential oils, causing a loss of color and flavor. This process typically takes one to two weeks, and the thyme is ready when the leaves are brittle and easily crumble.
Dehydrator Drying
For a faster method, a food dehydrator offers a controlled environment that preserves flavor compounds effectively. Spread the thyme sprigs in a single layer on the trays. Dry them at a low temperature, ideally between 95°F and 115°F (35°C to 46°C). Drying time is significantly shorter, usually ranging from four to six hours, until the leaves are completely dry and brittle.
Storing Dried Thyme
Once the thyme is completely dry, the leaves should be stripped from the stems by running your fingers down the sprig, discarding the woody portions. Storing the leaves whole, rather than crushing or grinding them immediately, helps to retain the maximum amount of volatile oils. Crushing the leaves should only be done just before use to release the concentrated flavor compounds.
The dried leaves should be placed into an airtight container, such as a glass jar with a tight-fitting lid, to prevent exposure to moisture and oxygen. To maintain potency, the containers must be stored in a cool, dark location, like a pantry or cupboard, away from heat sources. Proper storage ensures the dried thyme maintains its intense flavor for up to one year.