How to Make Medicinal Herb Infused Oil: Two Ways
I love making herb infused oil! In fact, it’s one of my favorite things to do with herbs from our garden, including lavender, chamomile, calendula and more. Whether you’re interested in making edible oils or homemade skin care products, this article will guide you through everything you need to know to make herbal oils of your own. It’s easy to do, and once you know the basics and best practices, the options of what you can create are endless!
There are two ways to make herb infused oils: using a quick heat method, or a slow cold infusion. Slow infusions are usually considered superior (most therapeutic) since they don’t expose the herbs or oil to heat – which can destroy or degrade the benefits of both. We’ll explore both methods today.
What is an herb oil infusion?
As the name implies, herb infused oils are created by steeping herbs in oil, such as olive oil, coconut oil, or sweet almond oil. As they infuse, beneficial compounds, fatty acids, and natural essential oils are drawn out of the herbs and into the surrounding oil. Later, the plant material is strained – leaving behind a medicinal herb oil. You can use any combination of herbs and carrier oils of choice (explored more to follow). I recommend using dry herbs for the best results.
Depending on the type of oil and herbs used, some herbal oils can be used in edible culinary creations – such as a salad dressing or marinade. Topically, herb infused oils can be used directly on skin or as a key ingredient to make salves, lip balm, soap, and other natural body care products. See a full list of ways to use your homemade herb infused oil at the end of this post!
What types of herbs to use for oil infusions?
Though we’re calling them “herbal oils” today, you can infuse all sorts of things in oil including flowers, berries, leaves, roots, stems, spices or fruit. For instance, we love making homemade rosehip infused oil – which is technically a fruit.
Use what suits your needs, and what you have available to you! For instance, calendula-infused oil can work wonders for skin conditions like rashes, dermatitis, or eczema, while comfrey is traditionally used for healing wounds. We usually rely on homegrown herbs, but occasionally buy organic dry herbs for infusions too. Starwest Botanicals offers a great selection of high-quality, ethically-sourced bulk herbs, flowers, spices and more.
Before you start, it’s important to become familiar with the properties, benefits, and possible side effects of the herbs you’re using – so do your research! I highly recommend Rosemary Gladstar’s book: A Beginner’s Guide to Medicinal Herbs, or her Herbal Recipes book.
Herbs commonly used in herb oil infusions:
- Citrus peels
- Hibiscus flowers
- Lemon Balm
- Lemon Verbena
- Marshmallow Root
- Plantain leaves
- Red clover
- Red raspberry leaf
- Rose hips
- Rose petals
- St. John’s wort
Carrier oil options to make medicinal infusions
There are dozens of different carrier oil options to choose from. I often use more than one type of oil in the same herbal infusion to reap the benefits and balance of both!
Jojoba oil, sweet almond oil, and argan oil are popular to make natural skin and body care products (and some of my personal favorites). Those oils are all highly healing and moisturizing in their own right, and even more so once infused with medicinal herbs! Edible oils such as olive oil, avocado oil, or hemp seed oil are great choices to make herb infused oils intended for culinary use.
Pop over to this article to learn more: 11 Best Carrier Oils for Skin Care, Salves and Infusions. It explores the pros, potential cons, comedogenic ratings, extraction methods, and other characteristics of 11 popular carrier oil options so you can pick the best oil for your skin type and needs. I personally prefer to use certified organic cold-pressed oils.
Using fresh vs dry herbs for oil infusions
It’s best to use dry herbs to create the most foolproof, safe, and long-lasting herbal oil infusions in most cases. Why? The high moisture content (water) found in fresh herbs can cause the oil to spoil and grow mold. Oil and water don’t mix, you know… Though some herbalists take their chances with fresh herbs, I’d rather play it safe than sorry. After all the time and effort of growing, harvesting, and infusing your herbs, moldy oil would be devastating!
Since dry herbs are more highly concentrated (and more can fit inside a container), using dry herbs can also yield a more potent infusion.
It’s okay to use fresh herbs in an infusion that you’ll use up fairly quickly, such as a small batch of basil or rosemary infused olive oil that you plan to use within a few weeks. It’s also less risky to use fresh herbs when using the quick heat method to make herb-infused oil, since some of the moisture can evaporate off while heating. However, I still recommend allowing the herbs to air dry for a day or two – or at least wilt and partially dry first.
How to dry herbs
You can dry herbs in a food dehydrator, hang them up to dry, or spread them on a screened herb-drying rack. Allow them to dry until they’re completely brittle and crisp, where no evident moisture or suppleness remains.
To air-dry herbs, it’s important to do so in a warm, dry location with good airflow. Using a fan nearby will help. Note that it may not be possible to air dry herbs in all climates or conditions. If it’s too cool or humid, the herbs may mold before they’re completely dry.
When using a food dehydrator, set it to the lowest temperature possible so the herbs retain their maximum beneficial properties. We almost exclusively dry herbs and flowers in our Excalibur food dehydrator. I love the large capacity, even and efficient drying, and precise temperature controls – including the “living foods setting” we use for medicinal herbs.
Should I wash herbs before drying them?
It depends. Some gardeners and herbalists avoid washing herbs before drying because the added moisture may prevent them from drying properly and potentially lead to mold. This is especially a concern when air-drying herbs, but shouldn’t be an issue when using a food dehydrator. If herbs are particularly dirty, the extra step of washing them may be preferred. Shake them out well (or even toss them in a salad spinner) to remove excess water after washing. I personally only wash herbs that I plan to use in cooking.
How to an Make Herbal Oil Infusion
- Herbs. Dried herbs are best for a slow cold infusion. Fresh herbs, wilted herbs, or dry herbs can be used with the quick heat method.
- A carrier oil of choice, such as jojoba oil, olive oil, sweet almond oil, or other.
- A glass container with a tight-fitting lid. Use something as small as a half-pint mason jar, or as large as a half-gallon jar! The size simply depends on how much herb infused oil you intend to make.
- Fine-mesh colander, reusable nut milk bag and/or cheesecloth for straining.
- Storage containers for finished oil, such as glass jars or amber dropper bottles.
- Optional: a slow-cooker or double boiler and probe thermometer (only if you intend to use the quick heat method)
Option 1: Slow Cold Infusion
The first option is the easiest, but does require a little patience: simply allow dry herbs to soak in oil at room temperature for several weeks. Known as slow or cold infusion, this method relies on a passive process to gently extract beneficial compounds from the herbs. Since it’s not exposed to heat, the maximum therapeutic properties of both the oil and herbs are retained. The herbs should soak in oil for a minimum of 2 or 3 weeks, up to 4 to 6 weeks for the most medicinal oil possible.
- Start by filling a clean glass container at least two-thirds full with dry herbs. Feel free to fill the container even more to create a stronger infusion. Yes, you can mix several different types of herbs together if you’d like!
- Pour oil over the dry herbs until they’re completely covered by at least an inch or two of oil (though they may float, that’s okay). If you wish to get more technical and measure, aim for an herb to oil ratio of about 1 part dry plant material by weight to 5 parts oil by volume. For example, 1 ounce of herbs to 5 fluid ounces of oil.
- Add a lid and set the jar in a dark place to infuse for several weeks. Some herbalists like to use the “solar infusion” method, steeping the herbs and oil in a sunny window to garner luminary warmth and energy. Yet others say that sunlight can reduce the potency of herbs or make oil go rancid more quickly. So, it’s a bit of a controversial topic! We’ve done both methods and never had oil spoil on us.
- Though not necessary, you can give the jar of oil a gentle shake or tilt from time to time. This is especially helpful during the first few days to rotate/submerge any “floaters” on top.
- Occasionally, condensation may develop near the top portion of the jar. If you notice this, simply open the jar and wipe it away with a clean paper towel.
- When the time is up, strain the herbs from the oil. I place a nut milk bag or layer of cheesecloth inside of a fine colander perched on top of a bowl, and then pour the oil through both. After it sits to drain a bit, I wring out any leftover oil from the herbs by squeezing the nut milk bag or cloth. Compost the leftover herbs.
- Transfer the finished herb infused oil into a clean storage container with a lid, and store it in a cool dark place. I like to use amber dropper bottles for face and body oil, storing the excess in a larger jar in the fridge for refills. The dark glass protects the medicinal herb oil from light degradation, so I can safely keep it out on my bathroom counter too. (See shelf life information below.)
- Now go enjoy your creation! I’ve included a list of ways to use medicinal herb oils at the end of this post.
Option 2: Quick Heat Method
The quick heat method is a simple, fast way to create herb infused oils without waiting for them to passively steep. Though we’ll be lightly heating the herbs and oil, it’s important to keep everything at 110°F or below to avoid degrading the quality of the oil and herbs. It’s okay to use fresh, wilted, or dry herbs with this method.
- Start by chopping up the herbs you wish to infuse. Smaller pieces = more surface area = stronger infusion.
- Add the herbs to a slow cooker (crock pot) or the top portion of a double boiler on the stove. If you don’t have a double boiler, create your own by nesting a glass bowl or smaller pot inside of a larger pot of water below. The top/inner pot should touch the water, but not rest all the way on the bottom of the lower pot.
- Pour over enough oil to submerge and cover the herbs by at least an inch or two. It isn’t necessary to measure, but you can if you wish. For fresh herbs, aim for an herb-to-oil ratio of 1 part fresh herbs by weight to 3 parts oil by volume (e.g. 1 ounce fresh herbs to 3 fluid ounces oil). For dry herbs, use 1 part dry plant material to to 5 parts oil by volume (e.g. 1 ounce dried herbs to 5 fluid ounces oil). For wilted herbs, use a ratio of 1:4.
- Gently heat the oil, but do not boil it. Between 95 and 110°F is ideal. Check the temperature with a probe thermometer and adjust the heat if needed. In a crockpot, use the lowest temperature or “keep warm” setting.
- Allow the oil and herbs to simmer together for at least 30 minutes, up to several hours for a more potent infusion. (Some medicinal herb oil recipes call for 12 to 24 hours in a slow cooker). Important: To prevent spoilage, leave the lid off so moisture from the fresh herbs can evaporate and escape. The more fresh the herbs, the longer I suggest lightly heating to ensure water content is reduced.
- Finally, strain and store the oil as explained in the “slow infusion method” section above.
How long does herb infused oil last?
The shelf life of herbal oils varies depending on the type of carrier oil used, if the herbs were adequately dried before steeping, and how the oil is stored. Most herb infused oils should stay good for about a year when made with dry herbs and stored sealed in a cool, dark place.
Some oils have a naturally shorter shelf life than others (such as grape seed and sweet almond oil), while jojoba oil can stay good for 5 years or more! Furthermore, refrigeration may be recommended for some oils. Refer to the oil manufacturer’s instructions, and see the expected shelf life of various carrier oils here.
If the herbal oil is used to make salve, lip balm, lotion, soap, or other goodies, the shelf life is extended since other preservatives are often used in those items. Beeswax is an excellent natural preservative for example!
Visible mold and/or sour, putrid, or otherwise “off” odors are signs that oil has gone bad or rancid and should be discarded. However, cloudiness is not usually a sign of spoilage (unless accompanied by a bad smell) and can be common in herb infused oils.
Ways to use herb infused oil
Here are some general ideas and ways to use medicinal herbal oils, but use your noggin’! Be sure the use is appropriate and safe for the type of carrier oil and herbs you used.
- As body oil or massage oil
- Facial moisturizer – just a few drops will do!
- Work a few drops through damp hair to soften hair and smooth split ends.
- As an ingredient in other homemade body care products like salve, soap, cream, lotion, lip balm, ointment, or other natural skincare products. Check out our lip balm and salve recipes here! For more ideas, I highly recommend this organic body care recipe book. It’s loaded with awesome recipes!
- If you used an edible carrier oil, you can use your herbal oil as a tasty marinade, salad dressing or in other culinary creations.
- As part of your oil cleansing method
- As spot treatment directly on scars, stretch marks, varicose veins, or other areas of concern.
- To soothe rashes, bug bites eczema, psoriasis, scrapes, burns, or other skin irritations
- On cracked heels, cuticles, feet, dry elbows, or other rough patches of skin.
- On chapped or cracked lips, or around your nose when it’s chaffed.
- To treat cradle cap on babies (check your carrier oil safety first).
- To remove makeup (but avoid contact with sensitive areas around your eyes)
And that concludes this lesson on making herb infused oil.
Easy, right? I hope that this tutorial helps you feel excited and empowered to go make herbal oil infusions of your own. Please let me know if you have any questions in the comments below. If you found this to be useful, please consider leaving a star rating or sharing this post. Well, I gotta run – it’s time to go strain our next batch of face oil! Thank you so much for tuning in today. Happy infusing!
Don’t miss these related posts:
- How to Make Salve or Balms 101: Simple Flexible Recipe
- Natural Lip Balm Recipe
- Soothing Homemade Lavender Salve Recipe
- Calendula Salve Recipe for Healthy Skin
- Homemade Hemp Oil and Salve Recipe
- How to Make and Use Homemade Lavender Oil, Calendula Oil, or Rosehip Infused Oil
How to Make Medicinal Herb Infused Oil (Slow Infusion or Quick Heat)
- Herbs. Dried are best, especially for a cold slow infusion. Fresh, wilted, or dry herbs okay for quick heat method.
- Carrier oil of choice (e.g. olive oil, sweet almond oil, jojoba oil, argan oil, or other)
- A glass container with lid, large enough to fit the herbs and oil you plan to use
- Fine mesh strainer and cheesecloth or a nut milk bag
- Optional: double boiler or crock pot (slow cooker) and probe thermometer, for quick heat method only
SLOW COLD INFUSION
- Fill a clean glass container at least two-thirds full with dry herbs.
- Pour over enough oil to cover the herbs by an inch or two.
- Add a lid, and let the infusion sit in a dark location for several weeks (at least 2, up to 6 weeks for maximum potency).
QUICK HEAT METHOD
- Chop herbs into small pieces
- Add herbs to a slow cooker, or the top portion of a double boiler on the stovetop
- Pour over enough oil to cover the herbs by an inch or two.
- Gently heat the herbs and oil for at least 30 minutes, up to 12 hours. Maintain temperature below 110F as much as possible.
- Leave the lid OFF so moisture can evaporate.
STRAINING AND STORAGE (both methods)
- Strain the herbs from the oil using a fine mesh colander lined with cheesecloth or a reusable nut milk bag. Let drip drain for a bit, then squeeze excess oil from the herbs.
- Transfer the finished herb infused oil into clean storage containers of choice. Compost the spent herbs.
- Store herb infused oil in a cool dark place. Refrigeration not usually necessary, but may extend shelf life.
- Most herb infused oils stay good for up to a year or longer. Check the instructions and expected shelf life of your particular carrier oil. Discard oil if it develops mold or putrid/sour smells.
- Enjoy your herb oil as-is, or use it as an ingredient in other products.
Question: my crockpot broke and I found one at a thrift store. I set my batch of comfrey salve to “low/warm” about 5 hours ago. Came back to it boiling. I assume it’s been boiling for quite some time. Is it now a bad batch? Thank you in advance!
Aaron (Mr. DeannaCat)
Hi Julia, what type of oil were you using and was the comfrey fresh or dried? I would be hesitant to use it as the medicinal benefits may be reduced by a bit, if you have access to more plant material and oil, you will likely be better off just making more oil and be sure to infuse the dried plant material and oil with a double boiler as it seems your crock pot is not up to the task. Hope that helps and good luck!
Could I fill my jar almost completely up with dried rosehips & hibiscus and then cover it with jojoba and sweet almond oil? I’m making a serum for my face!
Aaron (Mr. DeannaCat)
Hi Kay, absolutely! That’s what we do with our rosehips. Check out our article on How to Make Nourishing Rosehip Oil + 12 Ways to Use It if you are interested. Good luck and enjoy your face oil!
Question. Do you have a suggestion for what herb oil or salve would be best for exzema on a baby? My grandbaby has it BAD in a few spots and so far we have only used aquafor baby. She is 16 months. Dermatologist only offered that as a solution.
Aaron (Mr. DeannaCat)
Hi Gail, we have found that calendula oil or salve is the most medicinal and beneficial for a variety of skin ailments. We offer a calendula salve in our shop if you are interested, you can check out the reviews as it has helped countless people and babies with rashes, eczema, cradle cap, diaper rash, among other things. Read the ingredients, but barring any specific allergen to the specific person using the salve, the ingredients used are supposed to be safe on babies, with many of our customers having used it on their young ones. Hope that helps and good luck!