How to make herbal oils

by Jade Shutes

Summertime: A time for Herbal Infusions!

A herbal oil infusion is the combination of dried or fresh medicinal plant material and organic extra virgin olive oil or sunflower oil infused in the sun for a minimum of 4 weeks and up to 2 months. You can also infuse it in a crock pot or turkey roasting. Directions to follow.

Plants infused in olive oil are great for applications to the skin but can also, in the case of calendula oil, be used in salad dressings.

According to James Green the following herbs can be used dried when infusing:

  • Arnica
  • Burdock root
  • Calendula
  • Cayenne
  • Comfrey root and/or leaves
  • Elder flower
  • Ginger
  • Golden seal
  • Marshmallow
  • Mullein
  • Nettle
  • Plantain
  • Yarrow

According to James Green the following herbs must be used fresh when infusing:

  • Mullein flowers
  • St. John’s Wort
  • Garlic

**NOTE: Although the above plant material should be fresh, it should still be air dried for 24-48 hours to remove any moisture from the plant material. Moisture left in the plant will spoil the oil and potentially introduce bacteria/fungi into the final product.

First: sterilize all your equipment: bowl for weighing, glass jar, lids, and utensils. Do this by placing in boiling water or clean in dishwasher at high heat setting.

The standard concentration for herbal oils is 1 part plant material to 3 parts vegetable oil. You can weigh both your plant material and vegetable oil using a digital scale. I typically just fill the jar full of plant material, gently pressing the plant material down without compacting it down then cover the plant material with oil. It is up to you which method you use.

Solar method:
Fill jar with plant material (gently pressing down so it is full but not packed tightly) then cover plant material with sunflower or extra virgin olive oil, leaving at least 1 inch of oil above the plant material. Cover the mouth of the jar tightly with the lid assuring that no air can get in. Place jar outside in the sun, shake it daily and add more oil if necessary. After 4-8 weeks, the oil is ready for pressing out. Press and strain through cheesecloth (making sure all plant material is removed), bottle in sanitized jars, and store in cool place. Herbal oils should be used within 12 months.

**I often used the solar method for infusion of herbal oils while living in Seattle. However, since moving to North Carolina I found that the oil would boil in the heat of the sun/heat here so now I place my infusions in the window to get the sun but do not put them outside.

Double boiler: In a pinch, you can also use a double boiler to make a herbal oil. Simply place the measured plant material and oil into the top pot of the double boiler and place water in the base pot. Gently heat for 4 – 6 hours. Allow to cool. Once at room temperature, strain/press out oil.

Crockpot: I don’t personally recommend the crockpot as it gets to hot but if this is your only option: Place the weighed plant material and vegetable oil of choice in the crock pot. Turn crock pot onto the lowest setting, which is typically about 125 degrees F. This is as high of a temperature as you would want to use. Typically it is recommended at about 110 degrees F.

Turkey roaster: For large batches of herbal infusions, place your herb/oil mixture into the turkey roaster and set temperature at 110 to 120 degrees F. Stir you mixture daily. You will want to keep this going for up to 10 days. If using fresh herb, leave the lid slightly ajar to allow any moisture still in plants to escape rather than pooling on the lid and dripping back into the oil. (not good, mold for sure!) Once the allotted time has passed, strain through cheese cloth into a clean, sterilized jar.

FOR ALL METHODS: Once you have strained the herbal oil through cheese cloth into a jar, let sit overnight. The next day the herbal particles and ‘sludge’ will settle to the bottom. Decant off the clear oil into another jar. You can use the sludge for a body oil/rub and then compost the rest.

Herbal Oils for Aromatherapists
The three most common herbal infusions utilized by aromatherapists will be discussed below; however, it is important to remember that a wide range of medicinal plants may be used to create therapeutic herbal oils for application to the skin. Experiment!

Calendula (Calendula officinalis)

Calendula is an annual herbaceous plant, 1 to 2 feet high, with medium-green leaves and a much branching fragrant stem. The daisy-like flowers can be a delightful variety of light orange, yellow, and even golden to dark yellow flowers. It will flower all summer long and well into autumn. It is one of the easiest plants to grow and one that provides great joy.

Therapeutic benefits:
Calendula has been shown to be an effective antimicrobial (both antiviral and antibacterial), anti-inflammatory, antifungal, and vulnerary herbal oil. Clinical trials have shown that calendula increases cell proliferation and encourages the granulation process of wound healing.

Calendula is indicated for:

  • Wound healing/Tissue repair
  • Inflamed skin conditions
  • Poorly healing wounds
  • Cracked skin conditions
  • Burns
  • Insect bites
  • Cracked nipples due to breastfeeding (nontoxic to baby)
  • Damaged tissue, ulcers

Arnica (Arnica montana)

Arnica is a perennial herb and a member of the Asteraceae (compositae) family. It grows 30 to 60 cm tall and has yellow-orange flowers. Arnica montana occurs naturally in Central and Northern Europe. Other species of arnica that exhibit the same therapeutic benefits include Arnica cordifolia and Arnica latifolia. These species are found predominantly in the western United States.

Therapeutic benefits:
Arnica has been shown to provide antimicrobial, anti-inflammatory, wound healing and analgesic effects. According to Moore, “arnica works by stimulating and dilating blood vessels, particularly the specialized capillaries that control whether blood is piped into the small peripheral capillary beds or is shunted over to small veins, bypassing more widespread blood dispersal. Good, diffused blood transport and circulation into injured, bruised, or inflamed tissues helps speed up resolution and removal of waste products”.

Safety data: Only apply arnica on unbroken skin. Arnica is considered to be toxic internally. Avoid use if client has allergies to other species within the Asteraceae family, e.g., ragweed, German chamomile. Extended use may cause eczema (Mills and Bone, 2000).

Arnica is indicated for:

  • Bruises
  • Sprains and strains
  • Counterirritant to treat rheumatism
  • Burns, including sunburns
  • Hyperextensions
  • Arthritis, bursitis, or myalgia
  • Joint stiffness

St. John’s Wort (Hypericum perforatum)

St. John’s wort is a perennial herb with small bright-yellow flowers. It is native to Europe and Asia and naturalized in the United States and Australia. It grows abundantly in the Pacific Northwest and Canada. St. John’s wort flowers in early summer. The infused oil is made from the flower buds just before they open.

Therapeutic benefits:
St. John’s wort is known for a wide range of therapeutic activity. As an herbal oil, it has been shown to be an effective antimicrobial, anti-inflammatory, analgesic, and vulnerary agent.

St. John’s wort is indicated for:

  • Insect bites
  • Burns, including sunburns
  • Damaged tissue, slow healing wounds or ulcers
  • Bruises
  • Herpes lesions
  • Myalgia (muscle pain)
  • Dermal inflammation
  • Sprains and bruises (not as potent as arnica)

Here is some of our Calendula and Arnica oil infusions as they begin their solar journey.