How is Mullein Oil made?

The Mullein Plant

Native to Europe, northern Africa and Asia, the common mullein plant (Verbascum thapsus) of the Scrophulariaceae family is highly noticeable due to its tall flower stalks that emerge at midsummer. It is thought to have been introduced to North America in the 1700s as a medicinal herb, and thrives in roads cuts and waste areas.

Currently, common Mullein is a widely-distributed plant that can be found throughout the United States and Canada. It needs an environment with at least 140 days of growing season and between 50 and 150 cm of rainfall. Areas such as meadows, pastures, fence rows, roadsides, vacant lots, wood edges, forest openings, and industrial areas are where this plant is commonly found.

The Mullein Plant is renowned for its beautiful flowers, which open before sunrise and close by mid-afternoon. It has a wide variety of insects attracted to it, including bees, flies, butterflies and others. Only short- and long-tongued bees are able to effectively cross‑pollinate the plant's flowers. Autogamy also occurs as self-pollination at the end of the day if they were not cross‑pollinated beforehand.

Steam Distillation

How is mullein oil made? Mullein oil extraction is usually done through steam distillation. This process involves placing the plant material (leaves, flowers, and buds) in a steamer basket above boiling hot water. The steam then passes through the material and brings out its essential oils. There are two ways to do this – either with active processing that uses hot temperatures or with passive processing which uses cold temperatures.

Hot (Active) Oil Infusion: This involves heating mullein flowers or leaves in a double boiler for up to three hours with a carrier oil like olive oil. After being strained, the product is stored for later use. Cold (Passive) Oil Infusion: Start by gathering dried flowers or leaves of mullein and a carrier oil. Then, combine the two in an airtight container and let steep for 7 to 10 days. Finally, strain out the flowers or leaves from the oil.