How to Make an Herbal Infused Oil

If you're beginning to make your own herbal preparations, an infused oil is one of the first things I'd recommend learning.

It's simple, doesn't require much equipment, and once you have a jar of infused oil sitting on your shelf, you can turn it into all sorts of useful preparations.

Herbal oils are used in salves, balms, lotion bars, massage oils, and other topical preparations. And while there are certainly more complicated ways to make them, you don't need anything fancy to get started.

The basic idea is really quite simple:

You take a dried herb, cover it with oil, give the plant some time to release its constituents into the oil, and then strain the herb out.

That's it.

There are a couple of different ways I make infused oils, depending on how much time I have.

Start With a Dried Herb

When I'm making an infused oil, I prefer to use dried herbs.

Fresh plants contain quite a bit of moisture, and adding that moisture to an oil can shorten its shelf life and increase the possibility of spoilage. Drying the herb first gives you a much more stable preparation.

You can use herbs you've grown and dried yourself or good-quality dried herbs you've purchased.

Just make sure the herb is completely dry before you begin.

A Few Herbs That Work Well for Infused Oils

There are a lot of herbs that can be infused into oil, but these are a few of my favorites:

• Plantain – traditionally used in topical preparations for minor skin irritations and everyday skin care.

• Yarrow – traditionally used externally for skin and minor wounds.

• Calendula – one of the classic herbs for soothing and supporting healthy skin.

• Arnica – traditionally used externally for bruising, soreness, and minor aches. Arnica oil should not be used on broken skin.

• Comfrey – traditionally used externally in preparations for supporting the skin and minor injuries. It is generally recommended for external use only.

• St. John's wort – traditionally infused into oil for topical preparations, particularly for irritated or damaged skin.

These herbs all have their own characteristics, so you don't need to have all six in your apothecary.

Start with one.

Learn how it grows, what part you harvest, how to dry it, and how you like to use the finished oil.

Choose Your Carrier Oil

The next thing you'll need is a carrier oil.

There are quite a few oils that work well for herbal infusions, and the best choice depends on what you're making and how you plan to use it.

If you're not sure which oil to choose, I've written more about that here: [Choosing Carrier Oils for Herbal Preparations].

For most of my infused oils, I like to choose a relatively stable carrier oil that works well for the finished preparation.

The important thing is to use an oil you like and that makes sense for what you're making.

What You'll Need

You really don't need much equipment.

• Dried herb

• A clean, dry glass jar

• Carrier oil

• A mortar and pestle, grinder, or other way to crush the herb

• Fine mesh strainer, cheesecloth, or other straining material

• Clean bottle or jar for your finished oil

• Label

And if you're using the quick method:

• A double boiler or similar setup

Step 1: Crush or Grind the Herb

Before putting the herb into the jar, I like to crush or grind it.

You don't need to turn it into a powder. The goal is simply to break the plant material down enough to expose more surface area to the oil.

The more surface area the oil can contact, the more opportunity there is for the plant constituents to move into the oil.

A mortar and pestle works well for smaller amounts, but you can use whatever method makes sense for the herb you're working with.

Don't overthink this step.

You're just giving the oil a little more access to the plant material.

Step 2: Fill Your Jar With Herb

Put your crushed herb into a clean, dry glass jar.

I generally fill the jar about one-half to three-quarters full with the dried herb.

Don't pack it tightly.

You want to leave some room because dried herbs can expand once they are surrounded by oil.

This is especially important with herbs that are light and fluffy.

Step 3: Add the Oil

Pour your carrier oil into the jar, completely covering the herb.

Make sure all of the plant material is submerged.

At the same time, don't fill the jar completely to the top. Leave some headspace to allow the herb room to expand and to make it easier to stir or shake the mixture.

Once you've added the oil, give the jar a good stir with a clean utensil to help release any air pockets trapped among the herbs.

If the herbs settle and you notice dry material sticking above the surface of the oil, add a little more oil.

You want the herb completely covered.

Step 4: Choose Your Infusion Method

This is where you have two choices.

You can let time do the work, or you can use gentle heat to speed things up.

The Slow Method

This is probably my favorite way to make an infused oil when I have the time.

Put a lid on your jar and place it somewhere dark and out of the way.

I let mine infuse for approximately 4–6 weeks.

Give the jar a gentle shake every so often and check that the herbs remain completely covered with oil.

This method takes patience, but that's part of the fun.

There's something satisfying about putting a jar of herbs and oil on the shelf and knowing that, over the next several weeks, you're slowly making something useful.

The Quick Method

Sometimes you don't have four to six weeks to wait.

For a quicker infusion, you can use gentle heat.

Place the jar or a heat-safe container containing your herb and oil in a double-boiler-type setup and warm it over low heat for approximately 3–6 hours.

The goal here is gentle, steady heat—not cooking the herbs.

You don't want the oil boiling or getting excessively hot.

Keep an eye on the water level in your double boiler and make sure it doesn't evaporate completely.

I think of this method as a way to gently encourage the same process that would happen naturally over several weeks.

Step 5: Strain the Oil

Once your infusion is finished, it's time to separate the oil from the plant material.

Place a fine mesh strainer or cheesecloth over a clean container and pour the infused oil through it.

Let the oil drain through naturally, then press the herbs to get as much of the oil out as you reasonably can.

For some herbs, I'll strain the oil more than once to make sure I remove as much plant material as possible.

The finished oil should be relatively clear of bits of herb.

Any remaining plant material can contribute moisture and shorten the storage life of your oil, so good straining is worth the extra effort.

Step 6: Bottle and Label

Pour your finished infused oil into a clean, dry bottle or jar.

And label it!

I know it seems obvious when you first make it, but six months from now you may not remember exactly what is in that jar.

At minimum, I like to include:

• The herb

• The carrier oil

• The date it was made

If you've made several different oils, you will be very glad you took the extra minute to label them.

Store your finished oil somewhere cool and dark.

How long an infused oil lasts will depend on the carrier oil you used, how thoroughly the herbs were dried, how much moisture made it into the preparation, and how it is stored.

If it develops an unpleasant or rancid smell, changes significantly in appearance, or shows any signs of mold or spoilage, discard it.

What Can You Do With Herbal Infused Oil?

This is where it gets fun.

Once you have a finished infused oil, you can use it as-is for appropriate topical applications or turn it into another preparation.

One of the easiest things to make is an herbal salve.

Simply combine your infused oil with beeswax and allow it to cool into a soft, spreadable preparation.

And if you've been following along with my beeswax post, you'll know that I like to have my beeswax already portioned and ready to weigh out. That makes the next step even easier.

You can also use infused oils as an ingredient in balms, lotion bars, and other topical products.

A single jar of infused oil can become the foundation for several different preparations.

A Few Things to Keep in Mind

As simple as this process is, there are a few things worth remembering.

Use completely dried herbs. Moisture is the enemy of a good herbal oil.

Keep the herb covered. Any plant material sticking above the oil is more likely to introduce moisture and spoilage.

Don't rush the heat method. Low and slow is the goal.

Use clean, dry equipment. You don't want to introduce water or contaminants into your oil.

And, as with any herbal preparation, make sure you know the herb you're working with and understand its appropriate uses and precautions.

A few herbs also have specific considerations. For example, arnica is generally used externally and not on broken skin, while St. John's wort preparations can increase photosensitivity when applied to the skin.

Start With One

If you've never made an herbal infused oil before, don't feel like you need to make six different jars.

Pick one herb.

Plantain is an easy place to start. Calendula is another classic. Yarrow is a wonderful herb to learn if you have access to it.

Make a small jar.

Watch what happens.

Learn how the finished oil looks and smells. Use it to make a simple salve.

Then make another one.

Before long, you'll have a little collection of infused oils in your apothecary, and you'll have learned something much more valuable than simply following a recipe.

You'll have learned how to take a plant and turn it into a useful preparation.

And that's really what herbalism is all about.