Chamomile (either Matricaria recutita or Chamaemelum nobile) is a delicate herb prized for the soothing compounds found within its flower heads. The primary goal of drying is to remove moisture, which prevents mold and spoilage, while preserving the volatile essential oils that give chamomile its signature apple-like aroma and therapeutic properties. These oils, including chamazulene and bisabolol, are highly sensitive to heat and light, making preservation a careful balance between desiccation and quality retention. Drying the flowers immediately after harvest ensures the maximum concentration of these beneficial compounds is locked in for later use.
Optimal Harvesting for Preservation
The quality of the final dried product depends heavily on harvesting the flowers at their peak maturity. Chamomile blossoms should be picked when the white ray petals are fully open and horizontal, or slightly raised, but before they begin to droop backward toward the stem. This specific stage indicates the highest concentration of aromatic essential oils.
The optimal time to collect the flowers is typically late morning to midday on a dry, sunny day, after the morning dew has completely evaporated. Harvesting during this window ensures minimal surface moisture, which helps prevent mold during drying. Only the flower heads themselves should be collected, as the inclusion of stems and leaves can introduce a bitter flavor to the final tea infusion. The flowers should be gently pinched or snipped just below the base, avoiding rough handling that might bruise the delicate petals and cause essential oil loss.
Step-by-Step Drying Techniques
Preserving the delicate oils requires methods that remove moisture slowly and at low temperatures.
Air Drying
Air drying is considered the gold standard for achieving the best retention of the flower’s natural chemistry. This method involves spreading fresh flower heads in a single layer across a fine mesh screen or a clean basket, ensuring no flowers are touching to allow for proper air circulation. The location must be dark, well-ventilated, and kept at a stable temperature, ideally between 70 and 85°F (21–29°C), which minimizes the volatilization of aromatic compounds. Depending on humidity, this gentle process can take one to two weeks until the flowers are completely dry.
Food Dehydrator
A food dehydrator offers a faster, more controlled environment, useful in humid climates. The temperature setting should be kept at the absolute lowest available, typically between 95°F and 110°F (35–43°C), and never exceeding 115°F (46°C) to prevent the degradation of essential oils. Flowers should be arranged in a single layer on the trays. The drying process usually takes between 8 and 18 hours, requiring frequent checks for dryness.
Oven Drying
Oven drying is a less recommended but viable option for small batches, provided extreme caution is used with temperature control. The oven must be set to its lowest possible temperature, generally around 150°F (65°C), or simply rely on the pilot light or residual warmth. To allow moisture to escape and prevent the flowers from cooking, the oven door must be propped open slightly with a wooden spoon. Flowers are spread on a baking sheet lined with parchment paper and monitored continuously, as high heat can quickly scorch the petals and destroy the aromatic oils.
Testing for Dryness and Long-Term Storage
The success of the drying process is confirmed when the chamomile flowers are entirely moisture-free. A properly dried flower head should feel papery and brittle to the touch. When gently rubbed between the fingers, the petals and yellow center should easily crumble into small pieces. If the flowers feel pliable, soft, or merely bend instead of breaking, they require additional drying time to prevent mold growth.
For a definitive check, place a small sample of the dried flowers in a sealed glass jar for 24 hours. If any condensation appears on the interior of the glass, the flowers still contain too much moisture and must be returned to the drying process. Once fully dried, transfer the chamomile to an airtight container, such as a glass mason jar.
Storage containers should be kept in a cool, dark location, as exposure to light and heat accelerates the breakdown of the herb’s active components. Dried chamomile retains its maximum potency and flavor for about one year before the essential oils begin to diminish. Labeling the container with the date of drying helps keep track of freshness.