(this was meant to be posted a few weeks ago when I actually made the arnica ointment. sorry…)
Making infused oils with plants (fresh or dried) is an easy way to preserve their medicinal properties. This works because many plants contain oil-soluble components, such as essential oils, resins, basalms, waxes, and vitamins which can be extracted when placed in a carrier oil for a length of time. These infused oils can last up to one year, depending on the type of carrier oil you use. Olive oil is a classic example, because it has a long shelf life, and is readily absorbed by the skin, but many other options are available. Lighter oils, such as almond, jojoba, or sunflower oil can be used, or they can be blended together to utilize the benefits of multiple oils at once. Squeezing the gel out of a vitamin E (tocopheral) capsule, or adding tea tree oil can also help to preserve shelf life. Even hard vegetable or animal fats can be used, if heated with the herb.
A good list of the shelf lives of various carrier oils can be found here.
* If using freshly foraged herbs, make sure to let the herb wilt for a few hours to evaporate any excess moisture, which could cause mold and spoilage later on. A good preventative for spoilage is also to cover your jar, not with a tight-fitting lid, but rather with cheesecloth, or a paper towel and elastic, so that any excess moisture can escape.
* When using dried herbs, remember the rule of thumb is to use half the dried amount versus the fresh amount. So if a recipe calls for 2 quarts of -insert herb here-, remember to use only 1 quart.
As a general rule, use 1 cup (250mL) fresh herbs (or 1/2 cup dried herbs) to 2 cups carrier oil. Add anywhere between 1mL and 5mL vitamin E oil as a preservative after straining.
1) Traditional Method
Begin by making sure every utensil you’re using is clean and dry (moisture is bad, if you haven’t gotten the message yet!)
Take your plants and break them up (called garbling) by hand. This helps bruise the plant and make it more readily release its volatile oils.
Pour carrier oil over top of your plant, making sure to cover it completely. Exposed plants can cause spoilage. Cover your jar with a piece of cheesecloth or paper towel and an elastic to secure it.
Place in a dark, cool location, and shake or stir daily for anywhere between 2-4 weeks. Make sure to keep an eye on your oil and watch for any changes – cloudiness, or molding. If this happens, strain immediately (if it doesn’t smell off, it should be okay).
After 2-4 weeks, strain through a cheesecloth, or muslin, or a coffee filter, and add vitamin E or other essential oils for preservation. Pour into a clean glass container (preferably dark) and label with the date and what the infusion is. Store in a cool, dark place out of sunlight.
2) Sun Infusion Method (my favourite)
Follow all the directions of the Traditional Method for preparation.
Store jar on a windowsill in direct sunlight, allowing the heat of the sun to infuse the herbs into the oil. Steep for at least two weeks, before straining, adding vitamin E or essential oils, and storing.
* It’s especially important with this method to make sure not to put a tight-fitting lid on your infusion. The sun heats the oil, which causes condensation, which can ruin your entire batch if it’s left to mold.
3) Double-Boiler Method
This is a really good method to use if you need your oil faster than 2-4 weeks away, or if you don’t have the time to steep it slowly.
Fill the bottom portion of a double boiler with water (not too much though). Break up your herbs by hand into the top portion of the pot. Heat on low – if your heat is too high, you can burn your oil.
Pour the oil over your herbs and bring water (in the lower pan) to a low simmer.
Heat slowly for 30-60 minutes, stirring occasionally (although I’ve read sources that say as long as 2-5 hours). The lower you heat your oil, the longer it can infuse without ruining the quality of your infusion.
Let the oil cool to room temperature, and then strain through cheesecloth. Add vitamin E or essential oils, and then bottle and store in a dark, cool place.
* I don’t own a double boiler, so I used an oven proof dish inside of a large saucepan. It works, but be careful not to drip water in the dish!
* To make any of these infusions stronger, add a batch of fresh herbs to the infused oil, and repeat.
Arnica Ointment, taken from The Boreal Herbal, by Beverley Gray
1 cup (250mL) arnica flowers
1 1/2 cups (375mL) sunflower oil
1/2 cup (125mL) olive oil
1 TSP (5mL) vitamin E
1 oz. (30mL) beeswax
Add beeswax to a double boiler on low heat (or use an oven proof dish inside of a pot filled with water). Stir often, until beeswax is fully melted. Add full volume of infused arnica oil, and stir until fully combined.
I’ve since used it, and it works like a charm!
The Boreal Herbal, by Beverely Gray