Updated: Jul 22, 2021
Herbal oils have been made for hundreds of years, and likely thousands. This was a method every mother and grandmother learned at the knee of their mother. Harvesting the green and growing medicines of the farm and forest, and adding them to oil based 'carriers', then infusing the oil with the properties of the herbs.
Herbal oils are made for a variety of uses. Once an oil has been infused with herbs, the properties of the herbs are in the oil and can be delivered directly to the skin. And the skin is a wonderful delivery system!
A few examples are:
Chamomile flowers infused into oil for skin softening properties in creams and lotions. They are soothing to the skin and help calm itching and dryness.
Calendula (Marigold) flowers are another wonderful, calming ingredient. Basic salve made with Calendula is a wonderful product to prevent diaper rash and protect little cheeks from Winter wind!
To make an herbal oil there are two methods:
Method One: Traditional
Gather enough plant material to fill a jar loosely. The plant material can be gathered fresh from the garden and allowed to wilt a bit during the heat of the day, then ground up - or you can use dried plant material. Either way, grind the material into very small bits.
Put all the plant material into a large glass jar with a tight lid.
Fill the jar with oil to the absolute top. It is critical that no air space be left for moisture to accumulate as this can grow mold and destroy your oil!
Once the jar is sealed, place it in the garden on a flat stone where it will get as much sun light each day as possible. The sun light will, over the course of time, infuse the oil with the properties of the herbs.
Leave the the jar in the sun for 4-6 weeks, shaking periodically to make sure no air pockets are in the jar preventing equal saturation of the plant material by the oil.
The heat is what is actually infusing the oil. As you can imagine, leaving the jar out in the summer sun for 4-6 weeks would mean many days worth of heating up and cooling down at night.After the time has elapsed, remove the plant material and strain the oil into a clean glass jar for use as needed. I add a little pure Vitamin E oil as a preservative to keep my herbal oils from growing 'fuzzies'. If mold or fuzzy bits grow, discard the oil as it should not be used at that point.Moldy oils can NOT be used in medicine!
Method Two: Modern
The above method is fun and makes extremely good oil. However, most of us these days don't have the leisure time to wait 4-6 weeks for our skin care products!
To make an herbal oil faster - follow the instructions above up to the part about the glass jar with the tight lid. Instead of placing the herbs and oils into a jar, put them into a double boiler.
Set the double boiler on low heat, and keep water in the base at a simmer for around an hour. Ensure the oil does not boil.
The oil in the top of the double boiler will get quite hot.
After an hour or so, decant the plant material from the oil, straining the oil into a large, clean glass jar. It can now be used as needed for salves, etc. I still add Vitamin E oil to mine to increase shelf life.
Another thing that will increase shelf life is refrigeration if possible. The oils will last well on a cool, dark shelf though.
Note: Herbal oils will keep for approximately one year. After one year, the properties of the plant will begin to diminish sharply, making the oil far less effective. This is also true of dried herbs, although root and bark items last longer. All your fresh products should be made with the idea of discarding unused portions after a year or so.
If you'd like to pursue further reading about herbalism and making herbal oils, tinctures and more, here are a few authors I know are reputable and have written wonderful books:
Rosemary Gladstar - the matriarch of the U.S herbalism community, Rosemary has been teaching for many, many years. Her gentle, patient and down-to-Earth approach are life affirming and easy to follow.
Matthew Wood - an author with many books to his credit, Matthew has been writing and teaching about herbalism for ages. He has many students who credit him with their strong foundation of knowledge and skilled diagnostic abilities.
Susan Weed - from the 'wise woman' herbal tradition, Susan has been a teacher, healer and midwife for many. many years. I took a couple of classes with her years ago at the Green Nations Gathering, and she was an inspired speaker. She has written many books on herbalism for women dealing with child birthing and rearing, and menopause.