Herbal solar infused oils are really easy to make and are the base for other herbal products such as salves, massage and medicinal oils. It is important to choose a good quality oil – for medicinal oils, the oil of choice is usually olive oil; olive oil is relatively stable (meaning it doesn’t go rancid quickly), it is soothing and rich in omega fatty acids. However, it is not the usually the best choice for bath and body applications because it is heavy, feels oily, and always smells faintly of olives. For bath and body purposes try oils such as sweet almond oil, jojoba oil, avocado oil, or fractionated coconut oil.
Medicinal infused oils can be made using wilted fresh herbs, but it is easiest to make them using dried herbs which don’t have the water content as fresh herbs do. Water in herbal oil can introduce moisture and bacteria, which leads to spoilage. To fresh wilt herbs: place the fresh herbs in a basket or on a screen in a single layer, in a warm area out of direct sunlight, and let them wilt for at least several hours. They are ready to use when they look limp. Fresh wilting your herbs allows some of the moisture to evaporate so there is less chance of spoiling.
Shelf Life and Storage: Finished oils should be stored in a cool dark place to prolong their shelf life. Refrigeration is best. Stored properly, herbal oils made with olive oil will last for several months to a year. When an oil starts to smell “off” or loses its color, discard it.
There are two ways to make infused oils – the double boiler method and the solar infused method. I prefer to use the solar infused method as do most herbalists that I have read about and spoken with. However, the double boiler method works well if you are sort on time.
How to Make a Medicinal Infused Oil Using the Double Boiler Method
1. Chop the herbs and put them in the top part of a double boiler. A double boiler works better than a regular pan as the oil can over heat quickly and destroy both the herbs and the oil.
2. Cover the herbs with an inch or two of high quality oil (see above).
3. Slowly bring the oil to a very low simmer, you want just a few bubbles rising, but do not overheat or allow to boil. Simmer gently for 30 to 60 minutes. Check frequently to be sure the oil is not overheating. The oil will become deep golden or green and start to smell "herby" when it is finished and the herbal properties have transferred to the oil. The lower the heat and the longer the infusion, the better the oil will be.
4. Strain out the herbs, using a large stainless steel strainer lined with cheese cloth. Or press the herbs using an herb press or something similar (I use a potato ricer). Discard the spent herbs (composting them is great). Let the oil cool and then bottle it and label it. Make sure to label appropriately so you don’t forget what kind of oil you made! Note: if you put the labels on after you have poured the oil into the jars and wiped down the outside of the jar, the labels won’t get oily and stain.
How to Make a Medicinal Solar Infused Oil
1. Place herbs in a glass jar. Add a high quality oil (see above) so that oil is covering the herbs by an extra inch or two. Cover tightly.
2. Place the jar in a warm sunny spot and let steep for at least two weeks.
3. Strain out the herbs, using a stainless steel strainer lined with cheese cloth or press the herbs using an herb press or something similar (I use a potato ricer). Discard the spent herbs (composting them is good).
NOTE: For a double strength infusion – after straining add a fresh batch of herbs and the infused oil and allow to infuse for another 2-4 weeks.
4. Bottle and label your infused oil. Note: If you put the labels on after you have poured the oil into the jars and wiped down the outside of the jar, the labels won’t stain and get oily.
It is neat that although oils usually go rancid quite quickly when exposed to heat and light (like the sun) as long as the herbs are infusing the oils, they don’t go rancid. Once poured and strained they are susceptible to rancidity as any oil, but during the actual steeping they remain stable. I've had some calendula oil steeping for 8 months and it is still good.
What to Watch Out For
If condensation forms on the inside of the jar towards the top – open the jar and use a clean, dry cloth to wipe away the moisture. If condensation is a chronic problem, use a cover of thick layers of cheesecloth rather than a tight fitting lid to allow the condensation to evaporate.
If the herbal oil grows mold it means that there is too much water in the batch. Wilt the herbs longer (see above) or use dried herbs and make sure the container is completely dry.
If you need any clarification or have any questions, feel free to leave a comment.
To view the main page of the Herbal Learning Guide, including the links to other lessons, please click here.
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