Making Herb-Infused Oils

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The medicinal properties of herbs and roots can be extracted and infused in oils for a healthy, organic skin treatment.

Power of the Seed(Process Media, 2015) by Susan M. Parker gathers comprehensive information on oils in one place, making it a complete reference. Beginners can start with easy-to-follow recipes, while the adept have easy access to the most in-depth information available anywhere.

Oils and Herbs

Herbal oil infusions are time-tested combinations providing an amazing array of beneficial actions for the skin. By extracting beneficial botanical properties of leaves, flowers, stems, and roots into oil, the herb’s phyto-medicinal properties are transferred to the oil for treatment of the skin and body.

Infusing Herbs in Oil

Infusing herbs into oil or fat is probably one of the oldest forms of medicine-making. Traditional methods in herbalism and perfumery use oils to extract scent and medicine. Submerging plant material in oil transfers the healing properties, scent, and color to the oil. Infusions of fresh or dried herbs transforms oil into a healing balm to be used directly or included in a cream or salve. The herbs used can be dried or fresh. However, plant material that has had all of its moisture removed through drying is easier to work with. If not handled correctly, moisture in fresh plant material can spoil your infusion.

Oil has a tendency to weep or wick; it will push out the top of the jar, especially in warm weather, and make a mess. Leave some room in the top of your infusing jars to allow for oil expansion and place a tray beneath your oil infusions to protect your counters or furniture.

Working with Dry Herbs

Place the plant material in a canning jar, filling it about a half to two-thirds full. Pour the oil over the plants and work the oil down into the dried material with a chopstick or skewer. Keep plant material submerged fully in the oil or it can develop mold where it is exposed to air. Placing a paper coffee filter cut to the size of the top of the jar, press the plant material down below the surface of the oil. The coffee filter will help trap the plant material below the surface of the oil and will protect your infusion. When submerged, pour more oil to cover the filter and plant material, leaving a bit of room for the oil to expand, and close with a lid.

Working with Fresh Herbs

I like to infuse fresh plants because, rightly or wrongly, I sense a life force that is still present in them. But fresh infusions need a bit of extra care and attention to avoid problems. When submerging fresh plant material into oil, the water contained in the leaves and flowers can overwhelm the oil with too much moisture and the infusion can go off or become moldy.

Pick your plant leaves or flowers early to mid-morning, on dry days when dew from the previous night has evaporated. Make sure there is no moisture on the leaves or flowers, picking only clean plant material and brushing off any dirt or insects. The plant material should not be washed before infusing. Wilting the aerial parts of plants by setting them aside in an open weave basket or colander for a day or overnight allows for some moisture to leave before infusing. When ready, place the plant parts in a jar (canning jars work well) and fill it to the top. Press the plants down some, but don’t pack tightly. Pour oil over the plants, working it down into the material.

As with the dried herbs, keep plant material from poking out of the top of the oil by placing a paper coffee filter cut to the size of the top of the jar. Press the plant material down below the surface of the oil and filter, then top up with more oil to cover and close with a lid. Leave some room for the oil to expand in the jar.

Infusing Fresh Roots

Roots need to be washed free of mud and stones before infusing. When clean, lay them out on towels to air dry for several hours or overnight. The roots must be surface dry for a good infusion and to prevent mold growth. Cut the roots into smaller pieces and place in the jar. As with the plant tops, pour oil over the whole and seal, keeping plant material below the surface of the oil. Leave an inch or so at the top of the jar to make room for the oil’s possible expansion.

Time, Sun, and Heat: How to Infuse

Once plants are in the jar and oil poured over them, then what? The infusing process can take several forms; we will cover three of them here. Heat infusion is the fastest way to infuse, while cold infusing—letting the infusion proceed at its own pace—is the slowest. Solar infusing, using the powerful rays of the sun to imprint and create your herbal remedy, has its own benefits. Medicine-makers and herbalists use different methods based on their experience, location, and practice. Find the method that works best for you.

Sun infusion


Placing herbs to be infused in the sun speeds the transfer of plant constituents and imprints the sun’s energetic forces into the oil. Sun infusion is a method used by herbalists around the world to prepare St. John’s Wort. While traditional for infusing that herb, any herb fresh or dried can be sun-infused. The sun’s action on the plant material in the oil makes a special kind of energetic infusion.


After filling the jars with either fresh or dry material and oil, place them outdoors to allow the sun’s warmth and potent rays to assist in the transference of properties from plant to oil. Leave the jars for several days, up to a week. The length of time will depend on where you live. In the Pacific Northwest, I leave my jars for up to two weeks if the days are cool with scattered sun and clouds. In a very hot southern environment, I might leave the jars for only a few days.


The sun is a vital source of life. By using the sun’s energy, the healing properties of the oil is heightened.

Plantsto try

St. John’s Wort is the most traditional, but all plants can be sun infused; calendula, lavender, rosemary, lemon balm, yarrow, comfrey, roses, mugwort, violet leaves, lilac flowers, and elderflower are a few ideas.

Heat infusion


By using low heat, the infusion process is sped up. This process can be done in a crockpot or by low-heat oven method.


Put the oil and herbs into the crockpot or pan. Leave temperature settings on very low heat for several hours. Watch the temperature with this method so that the oil doesn’t overheat. It should remain in the range of 120 to 130 degrees. Too much heat will cause the infused oil to become rancid more quickly.


Infusing can be done in a concentrated period of time, and the oil then stored away for use in future products. The method provides an economy of time and attention.

Plants to try

Any of the above plants can be infused by this method, dry or fresh. Also try with evergreen boughs, eucalyptus, jalapeno peppers, garlic, among others.

Cold infusion


Time becomes the infusing action in this method and no additional heat is used. Jars of macerating oil can be left on a counter or in a cupboard while the transfer of phyto-chemicals from plant to oil occurs. Indoors, this can take up to six weeks or longer.


Place herb and oil filled jars in a cupboard or on a counter where they can stay for up to six weeks or more. Place a tray under the jars to protect against oil weeping onto counters or down walls. Shake the jars from time to time to disperse the oil. Six weeks is the herbal standard and longer infusion times are not necessary.


The ease of this method is clear and there is a reduced likelihood of too much heat causing polyunsaturated oils, if used, to go rancid. The oils can sit for an extended period of time indoors, away from heat and light.

Plants to try

Many plants with the exception of calendula can stay in the infusing oil for even longer periods; rose petals, St. John’s Wort, rosemary, lavender. Some herbs however develop exceptionally strong odors that can interfere with future product making. Remove these herbs from the oil after the six week infusion period; calendula, lilac blossoms, plantain, comfrey are some of these.

Which Oils to Use?

This book has covered a number of oils, but which one is best? This depends on what you want to achieve. If making salves or products, the longer shelf life the better. Cost is a factor too—infusing takes a lot of oil, some of which is lost in the process. End use and skin feel are other considerations. Most herbalists in the US use olive or pomace oil, as it is a fairly low-cost oil with a long shelf life. Older European traditions call for lard, the fat of pigs, as it is a stable, saturated fat and compatible with the skin. I find olive oil too oily for some of my products and switched from olive to sesame oil a number of years ago. At the time sesame oil was inexpensive (though that is no longer true), and it’s as stable as olive oil. Sesame oil contains two natural preservatives, sesamin and sesamol, which help keep infusions for a good length of time when stored in the cool and dark. A note on sesame oil: sesame oil comes in two versions, unrefined and toasted. The toasted variety is strongly scented for Asian cooking and not usually used in skin care. Find the untoasted refined or unrefined type for making infusions.

Coconut oil can be used to extract scent from very aromatic flowers. A jasmine infusion turned out well by adding multiple rounds of flowers to the just-warmed oil over the period of a week. This is a form of DIY enfleurage that is very rewarding.

In general, oils high in omega-9 oleic acid are best for infusions. Oils like flax and hemp can go rancid quickly and take your herbal medicines with them. Omega-3 and 6 oils will not last long and the heat or time used to infuse will speed their oxidation process. Experiment on a small scale with pints or quarts to see which oil is best suited for your needs.

Which Plants are Best?

Herbal books that can be used as points of reference abound. Here are a few suggestions to begin: evergreen trees, pines, spruce, firs, and eucalyptus create a warming massage oil. Or try flowers: roses, calendula, lavender, yarrow, lilacs, St. John’s Wort, dandelion, elderflowers. Leaves such as lemon balm, rosemary, violet, mugwort, sage, angelica, and lady’s mantle are also good—take a look around you and see what’s growing. You won’t be able to capture many of the scents, but there are lots of nuanced and beneficial properties that will be imprinted in the oil. Make sure the plant material is wild, organic, or just natural, not sprayed or treated with chemicals or pesticides. Those won’t make good medicine.

Pouring Off

When the infusion is done, it is time to pour the oil off the plant matter. You will need a bowl, a sieve or strainer, and a bottle to put your infused oil in. Empty the contents of the infusing jar into the strainer and allow the oil to drain into the bowl. You can press down on the plant to extract as much oil as possible. Then, using a funnel, pour the oil into your bottle and label with the plant name, date, and extracting medium. Spent rose petals and calendula petals can be added to soaps for botanical interest. Compost other unused spent plant material.

If you have used fresh plants to infuse, you may experience the development of a gummy snot-like material that forms in the storage bottle over time. The oil hasn’t spoiled, just strain to use. I put this material in soap batches.

Troubleshooting Oil Infusions

Sometimes, even with the best practices, small pieces of the plant rise above the top of the oil and mold. This does not mean your oil is spoiled. With great care, lift any moldy bits off the top of the oil and throw away. Spoons, spatulas, and chopsticks are useful for this. Then, take a paper towel with rubbing alcohol and wipe the inside neck of the jar to remove mold spores. Pour the oil through a sieve and compost the plant material. Bottle, label, and store.

The oil is spoiled when there is mold all through the oil and jar, not just on the very top. This means the plant material was too wet, or there was still moisture on the leaves. The oil is not salvageable and should be thrown out.

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Reprinted with permission fromPower of the Seed, by Susan M. Parker and published by Process Media, 2015.