There are many ways of using herbs; fresh, dried, boiled (tisane), distilled (essential oil), in alcohol (tincture) and in vegetable oil (maceration/herbal oil). Herbs are full of active chemicals that can be drawn out in different solvents such as alcohol, vegetable oil or glycerine. A maceration or herbal oil is when vegetable oil is used (oil extraction). Some well-known macerations are easily found in the market-place, such as Arnica (Arnica montana), Marigold (Calendula officinalis) and St Johns wort (Hypericum perforatum), but there are many others. Extracting herbs in oil is a simple process that easily can be done at home.
As always, quality plays a great role in the final product; you need to use the very best herbs and vegetable oil. One of the easiest vegetable oils to find for the purpose is organic sunflower oil which is most often used. The finished herbal oil has its own specific properties and in ancient time they were used as medicines and unguents for perfumery. The macerated oils carry some color from the plant, St Johns wort is red, and have their specific therapeutic properties.
Macerations can be used in all kind of products that are fatty; creams, oils, liniments and can help with a wide variety of problems; muscular aches, sprains, cramps, depression and skin-problems. Some are anti-inflammatory and promote wound healing. Since they are active substances, use 5-30% in a blend for desired effect. In large dosages they can be slightly drying or even irritating to the skin. Macerations are excellent to use for people who are very sensitive to essential oils as they are milder in their action on the skin.
I have made many macerations through the years, trying different plants and vegetable oils. I found Jojoba oil to be excellent for flowers, Sunflower oil as well. I use Olive oil for St Johns Wort since there is a true affinity between them. Today I find it easier to buy the macerations I use the most; arnica, calendula, hypericum, comfrey and some others. But there is one maceration I make every year for my own luxury, and that is with roses. In the early days I always used Jojoba for the roses but today I use a very fine organic cold pressed sunflower oil from where I live. It gives me a beautiful oil that I use in my facial products. The scent is rather faint and a bit greenish, the texture is absolutely wonderful. I use this in a dosage of 20% in any given product.
Their shelf-life depends on what vegetable oil was used and how it is stored. Better to make smaller quantities so they are used up during the season and more can be made the next year. In this way you also find your favourites and you learn to “better” the process each time.
Pick your chosen herb at the right time of day and season and fill a glass jar, cover the herbs with cold-pressed organic vegetable oil, cover and set in the sun. The jar should be turned regularly and left in the sun for a month. When macerating flowers you need to exchange the flowers in your jar every so often, usually every 2-3 days, depending on what flower you are using. For roses I exchange the petals every 3 days. Once the oil is saturated you strain, filter and bottle it. Store in a cool and dark place.