Thyme, a member of the mint family, is a highly aromatic herb valued in kitchens worldwide for its earthy, slightly floral flavor profile, which deepens with cooking. The small, pointed leaves contain volatile oils rich in thymol, which gives the herb its distinct taste and scent. Since fresh thyme is often purchased or harvested in quantities larger than immediately needed, preserving the surplus is a practical way to ensure its flavor is available year-round. Extending the herb’s usability requires methods that minimize the loss of these flavorful compounds while preventing spoilage.
Short-Term Storage Methods
For fresh sprigs intended for use within a week or two, simple refrigeration is the most effective way to maintain quality. One common technique is the “bouquet” method, where the stems are placed upright in a small glass of water, much like a vase of flowers. This setup is then loosely covered with a plastic bag and stored in the refrigerator. The water should be changed every few days to keep the herb hydrated and crisp.
A simpler approach involves wrapping the unwashed sprigs in a slightly damp paper towel. The wrapped bundle is then placed inside a loosely sealed plastic bag or an airtight container before being refrigerated. This method provides a humid environment to prevent the leaves from drying out, keeping the herb fresh for up to ten days.
Long-Term Preservation Through Drying
Drying is a traditional and highly effective method for long-term storage, as thyme retains a significant amount of its flavor when moisture is removed. The simplest method is air drying, which involves gathering small bunches of sprigs and tying them at the base of the stem. These bundles should be hung upside down in a warm, well-ventilated area away from direct sunlight, such as a pantry or closet.
Depending on the humidity, air drying can take anywhere from three days to two weeks. The thyme is ready when the leaves are brittle and crumble easily between the fingers. For a faster result, a food dehydrator is effective, typically operating at a low temperature of about 105°F for two to five hours until the leaves are fully crisp.
Using an oven is another quick option, requiring the lowest possible temperature setting, usually between 170°F and 180°F. The sprigs should be spread in a single layer on a lined baking sheet, and the oven door should be propped slightly ajar to allow moisture to escape. Drying generally takes one to two hours, with the thyme checked every 15 minutes until it is completely dry and breaks apart readily. Once dried, the leaves are stripped from the stems and stored whole in airtight glass containers in a cool, dark location.
Freezing Thyme for Extended Use
Freezing is an excellent alternative to drying because it helps preserve the herb’s color and volatile oils, resulting in a flavor closer to fresh thyme. One simple technique involves freezing the sprigs whole after gently washing and thoroughly drying them. The sprigs are placed in a single layer on a tray for a quick flash-freeze, which prevents clumping.
After flash-freezing, the sprigs can be transferred to a freezer bag or airtight container, with as much air removed as possible before sealing. When needed for cooking, the frozen leaves can be easily stripped from the woody stems, which become brittle in the freezer.
A more convenient method is creating flavor cubes using a liquid medium and an ice cube tray. The thyme leaves are removed from the stems, finely chopped, and packed into the wells, filling them about two-thirds full. A neutral-flavored oil, such as olive oil, water, or melted butter, is then poured over the herbs to fully submerge them. Once frozen solid, the cubes are transferred to a labeled freezer bag for easy, pre-portioned use in cooking.
Creating Thyme Infusions and Compounds
Incorporating thyme into other products is a unique way to preserve its flavor while creating a convenient cooking or seasoning ingredient. Thyme-infused vinegars are simple to make and offer a bright, acidic flavor for salad dressings or marinades. This process involves steeping fresh or dried thyme sprigs in a high-quality vinegar, such as white wine or apple cider, for approximately two weeks in a jar sealed with a non-metallic lid.
After the infusion period, the liquid is strained to remove the plant material and then bottled. The resulting product keeps well in a cool, dark place. The herb’s robust flavor is also easily transferred to dry ingredients like salt and sugar. For thyme salt, dried thyme leaves are crushed and mixed with coarse salt, creating a flavorful seasoning rub for meats or vegetables.
When considering thyme-infused oils, caution is necessary due to the risk of botulism. Fresh herbs immersed in oil create a low-oxygen environment where Clostridium botulinum spores can thrive at room temperature, producing a dangerous toxin. For safety, any homemade oil infusion containing fresh thyme must be refrigerated and used within a few days, or the oil should be made exclusively with fully dried thyme to minimize the risk.