by Rosemary Gladstar:
There are four common methods used for making oils. Each of these
methods is highly effective and is used professionally as well as for
use. I myself prefer the methods that employ a long, slow heating
process, such as the solar, oven-extraction, or Crockpot or roaster-oven
techniques, over the double-boiler method. But there are times when
I've been thankful to be able to make a medicinal oil in the short time
made possible by the stovetop method.
Solar Infusion Method
Using the simplers' measure, place the desired amount of herbs and
oil in a glass jar. Cover tightly. Place the jar in a warm, sunny
spot. In Europe and the Mediterranean the jars are placed in sandboxes
to attract greater amounts of heat. When traveling in Switzerland, my
daughters and I were fascinated and excited to find jars of St. John's
Wort flowers steeping in oil on the porches and balconies of may
people's homes. The beautiful yellow flower of St. John's wort turn the
oil a bright red. It is truly beautiful and amazing!
Let the oil/herb mixture infuse for two weeks. People always ask
why the oil doesn't go rancid sitting out in the hot sun. According to
natural laws, it should. But for some magical reason, it seldom does.
I believe it's because of the alchemical fusion of the sun, the herbs,
and the oil. But once strained, the oil will definitely go rancid very
quickly if left in the hot sun.
At the end of two weeks, strain the herbs, rebottle your beautiful
herbal oil, and store it in a cool dark area. If you wish a stronger
oil, add a fresh batch of herbs to the oil, and infuse for two more
weeks. This will double the potency of your medicinal oil.
Using the solar method for making medicinal oils is my favorite
method. I learned it from the wise old Gypsy herbalist, Juliette de
Bairacli Levy. Though a bit more time-consuming than the other methods,
it has the added benefits of the sun, the wisdom of the elders, and a
delightful array of bottles sitting in a sunny spot in the garden or
windowsill of your home.
Oven Extraction Method
Place the oil/herb mixture in a pan with a tight-fitting lid or in
glass canning jars. Put the pan and/or jars in a larger pan with
sufficient water to cover up the bottom half of the container. Turn the
oven on the lowest temperature possible and allow the herbs and oil to
infuse for several hours. Check frequently to prevent the oil from
overheating and burning.
Double Boiler Method
Place the herbs and oil in a double boiler, cover with a
tight-fitting lid, and bring to a low simmer. Slowly heat for one-half
to one hour, checking frequently to be sure the oil is not overheating.
The lower the heat, and the longer the infusion, the better the oil.
This is a quick and simple method that appeals to many modern-day
herbalists. One word of caution, however: oil heats up very quickly.
Be mindful of the temperature. Your preparation can quickly go from a
nice herbal oil infusion to deep-fried comfrey leaves.
Crockpot and Electric Oven Roaster Method
Both Crockpots and electric oven roasters allow for a long, slow
cooking process. The roaster is most often used by small professional
companies making quality herbal products. The herbs can macerate in the
oil for a long period of time (two to four weeks) and the resulting oil
is of a superior quality. Electric roasters can often be found quite
inexpensively at bargain shops and second-hand stores. They are in hot
demand by herbalists!
Place the herbs and oil in the Crockpot or roaster and turn to the
lowest heat. Place the lid on and let the mixture steep for the desired
length of time. The heat is generally higher in the Crockpot and
usually two to four hours is sufficient to prepare good-quality herbal
oils. Check frequently to protect against overheating and burning. In
the roaster, the herb/oil mixture can steep for two to four weeks. It
gives a superior, dark-green herbal oil.