A couple of weeks ago I talked about growing and drying one of my favorite garden plants: Calendula. Now I want to continue this little mini-series by talking about how to make a Calendula oil infusion. Simply put, infusion is the process of extracting flavor, color or active compounds from plant materials by steeping them in a liquid solvent like water, oil or alcohol. Making an infusion is much like making a cup of tea, or a pitcher of sun tea. There are several different ways to go about making an infusion.
My favorite method is the slow way, usually called cold infusion. Fill a clean glass jar about half way with the dried calendula, then add the oil of your choice (more on that in a minute) until the flowers are completely submerged. Cap the jar with a tight fitting lid, then let the jar sit for about a month. A sunny windowsill is a good spot for it, as the sun will gently heat the oil and coax the active components from the flowers. Every few days, give the jar a good shake to move the flowers around in the oil. You can do this with other dried herbs as well. Lavender is one of my favorites, but I have also infused oils with plantain and stinging nettles for an anti-itch salve, and botanicals such as annatto seed and alkanet root to give natural color to soaps. Herbs and flowers should always be thoroughly dried before infusing in oil, since even a small amount of moisture can result in spoilage or in toxins developing in the oil.
You choice of oils is a matter of personal preference, and the final use should dictate your selection. For soap making I often use olive oil, since it is used in all our soap recipes and also makes a fairly inexpensive choice. You can use a ‘light’ olive oil if you want to avoid a strong olive oil smell. But even though olive oil is great for the skin, it’s a bit greasy for my tastes so I also like to use sweet almond oil for infusions that will ultimately wind up going directly on the skin. Jojoba oil and extra virgin coconut oil are also good oils for infusing.
A quicker way to infuse the oil is with a hot infusion. You can easily make an infused oil in one afternoon or evening with one of these methods using heat. If you have a crock-pot, there are two different ways to use it. When I made Coffee Infused Oil earlier this year, I put the oil and coffee grounds directly into a small crock-pot. And when I made annatto and alkanet infused oils a while back, I put the oil and botanicals in individual pint glass jars, then put the jars in a large crock-pot and filled it with hot water. I turned the slow cooker on low and let the jars sit for about 8 hours. Using the jars makes for easy cleanup.
Another method using heat involves using a candle warmer. My wife wrote a tutorial on that a couple of years ago called Infusing Herbs. The candle warmer serves much the same purpose as a crock pot in providing a controlled low level of heat.
Whichever method you use, after the oil is infused you need to strain out the calendula or other herbs, flowers or botanicals. One way is to set a fine mesh metal strainer over a glass measuring cup or bowl, and pour the oil into that. You can also put a paper coffee filter inside the strainer if you want the oil to be extra clear. My wife likes to put a clean knee high nylon stocking over the jar and use that as a strainer. The stocking can then be washed and reused for later straining operations.
Once the oil is strained, you should pour it into a jar and label it with the contents and the date it was infused. Be sure and note which oil you used too. Store the oil in a cool dark place, much like you would a cooking oil. Use within a year, and do not use if the oil develops a rancid smell. You can add a few drops of vitamin E to help preserve the oil, and the oils can also be refrigerated to keep them fresh.
Infusing oils with calendula or other herbs is a great way to capture the essence of those flowers and herbs in a jar. I hope you have enjoyed reading about some of the ways you can make your own infusions. I’ll be back in a bit to share a couple of things I like to do with the calendula infused oil.