Woodruff is a perennial herb celebrated for its unique, pleasant scent and versatility. Often found carpeting the forest floor, this delicate plant holds historical relevance, particularly in European traditions. Its foliage, unassuming when fresh, transforms upon drying into a fragrant material prized for its aromatic qualities, maintaining its popularity from the Middle Ages to modern culinary applications.
Defining the Plant
The herb commonly known as Woodruff is botanically identified as Galium odoratum, a low-growing herbaceous perennial belonging to the coffee family, Rubiaceae. It is native to the cool, shaded woodlands spanning across Europe, North Africa, and West Asia, typically reaching a height of 6 to 12 inches with slender, square stems.
Its appearance is characterized by bright green, lance-shaped leaves arranged in distinctive whorls of six to nine leaflets around the stem. In late spring to early summer, the plant produces clusters of tiny, star-shaped flowers with four white petals. The species spreads horizontally through creeping rhizomes, forming dense, mat-like groundcover, making it a popular choice for shady garden spots.
Distinctive Aroma and Flavor Profile
The sweet scent of Woodruff is due to the aromatic compound coumarin. In the fresh plant, coumarin exists as a non-volatile, odorless glycoside, and the fragrance is only released when the material is damaged, wilted, or fully dried.
This release involves an enzymatic reaction that cleaves the glycoside, liberating the volatile coumarin molecule. The resulting aroma is often described as a distinctive mix of fresh vanilla and newly mown hay, sometimes likened to sweet almond or fresh grass. While the aroma is intensely sweet and appealing, the flavor when tasted is subtly bitter, which balances its use in food and beverages.
Traditional and Modern Applications
Woodruff has a long history of application, transitioning from a household freshener to a modern culinary ingredient. Historically, the dried herb was used for various purposes:
- To scent linens.
- Stuffed into mattresses for its purported sleep-inducing properties.
- Scattered on floors as a strewing herb to mask odors in medieval homes and churches.
- As a natural choice for potpourri and sachets.
- Serving as a traditional moth deterrent due to its enduring fragrance.
In modern times, the herb is most famously used in German culinary tradition to flavor a celebratory spring beverage called Maibowle, or May wine. This traditional punch is made by steeping the wilting sprigs in white wine, which imparts its signature sweet, grassy flavor. Beyond beverages, the herb is now used to flavor desserts such as jellies, sorbets, syrups, and ice cream.
Safety Considerations
The presence of coumarin, the source of Woodruff’s appealing aroma, necessitates caution due to its potential for toxicity in high concentrations. Coumarin can act as a blood thinner and, in extremely high doses, has been linked to liver damage. Since the coumarin content in dried Woodruff can reach up to 0.6% by weight, moderation is advised when consuming the herb.
Scientific studies indicate a tolerable daily intake (TDI) for coumarin in humans is approximately 0.1 milligrams per kilogram of body weight. While culinary use is generally considered safe at low exposure levels, excessive or prolonged high-dose consumption is not recommended. Individuals taking anticoagulant medications or those who are pregnant should specifically avoid consuming products containing concentrated coumarin.