When trying to figure out the best way to infuse oils for soapmaking, the recommended method I came across was to put your herbs in a jar, pour your oils on top, place them in a sunny windowsill for a month, shaking every couple of days. The problems are I have a house surrounded by some large oaks (not a lot of sunny windows), an older house with lots of low windows (and a ten-month old who wants to grab everything), and a cat who would think it is her duty to knock anything off a windowsill the baby didn’t take care of. So that method didn’t work for me.
The basic principle of infusing oils is warmth + oils + herbs = infusion, so I gleaned what I could from the wonderful interwebs and came up with this. There are multiple purposes to infusing oils: to infuse the color from the plants, the smell (though it doesn’t always carry over past the saponification process) and the properties (such as the skin-soothing nature of calendula). Also, I am sure this method could be used for infusing oils for cooking.
You Will Need (And Probably Have Most Of):
- a crockpot, ideally with a ‘warm’ setting
- olive oil (you can use others, but olive oil is inexpensive, easy to find and found in nearly every soap recipe ever)
- your dried herb of choice, such as calendula, lavender, chamomile or peppermint.
- a few coffee filters
- a mesh strainer
- a jar or container big enough to hold your oils
- rubber gloves (optional)
Infusing the Oils
This is not an exact science so you don’t have to be exact. Play around with the amounts and experiment to find what works best for you. I usually use between 1/2 to 1 cup of dried herbs to a little more than 32 ounces of oils. A few notes here: use dried herbs because any wetness in your oils can form mold, and mold is not good; also, if you are using this for a specific recipe (i.e. infusing 2 lbs of olive oil for a small batch of castile), use a bit more. Some of the oils will get lost or absorbed into the herbs during the process.
Crush your herbs lightly. A mortar and pestle is great, but I don’t have one, so I tend to break them up gently into the empty crockpot. You don’t want to turn them into powder. Pour your oil over the herbs and turn your crockpot on warm. And leave it. Go read a book or do dishes. Play a game on your phone or take your kid for a walk. Come back in half an hour and give it a stir and put the lid back on. Now, depending on the warmth of your crockpot, you might want to turn it off for a bit. Trust me when I say your crock pot will stay warm for a good long while. Mine gets the oil to 200 degree even on the ‘warm’ setting, so I tend to run it one hour on, half an hour off, another hour on and so forth. Sometimes, I leave it on and leave the lid off so excess heat can escape. You don’t want to cook the herbs, after all.
Just like the amounts, play around with the time. I usually infuse for about six hours, sometimes a little more, depending on what’s going on in the household. My timing usually runs from when the baby takes her first nap around 10 am, to just before my husband gets home from work, if that tells you how I measure time around here. A good way to check on your herbs: smell them, pull a little out and look at the color, or dip your finger in and taste a bit. For example, my peppermint infusions take on a lovely minty green tinge and put a tingle on my tongue. When you think it’s done, turn it off and let the whole thing cool.
Straining the Oil
This is pretty simple. I like to take one of those cat-eared mesh strainers, set it over a big bowl, spread out a coffee filter in it and pour some of the oil in. At this point, I usually keep the actual crock out of the crockpot and just keep it on the counter beside my bowl, with a paper towel underneath to catch any oil drips. Also, getting oil on the heating element of the crockpot just seems like a bad idea.
It’s going to be a slow drip, so stay kind of close to come back and pour a little more oil every few minutes. This is a great time to catch up on email, read your kid a series of board books or let the dog out multiple times so she can sniff the yard, not go to the bathroom and come back in. Once all of your oil has dripped through and the majority of your herbs are now in the lined strainer, put on those rubber gloves. Very gently, pick up the herb-filled coffee filter and squeeze as much of the oil out of it as you can, still holding it over the mesh strainer. You want to try to avoid any escaped herbage falling into your bowl, if you can. You’d be surprised how much oils are held in those herbs, so really give it some good long squishes. Toss the filter and herbs in the trash, wash your oily gloves with your hands still in them, take the gloves off and go get your funnel.
Storing the Infused Oil
Some people will say you need to store your oils in a dark amber bottle to protect the from light and blah, blah, blah. Well, I don’t know about you, but I’ve never seen a large amber bottle at my local big box store. I use one of those lovely plastic ones with a screw-on top and flip-top cap and measured markings up the side. Just store it in a cool, dark place and you’ll probably be fine since, if you like soaping as much as me, it will likely get used up pretty soon.
Anyway, grab your container, stick your funnel in the top, arrange a coffee filter in the funnel and start pouring the oil through again. This second filtering isn’t necessary, but I usually have some visible sediment after the first filtering, so I like to do this. Depending on the size of your funnel, this can take awhile, so I don’t recommend starting right before bed, unless you can safely assure your cat isn’t going to knock it over in the night. Like the first time through, pour some oil, go off and come back in five or ten minutes. Keeping the funnel full will help push your oil through the filter faster. Rinse and repeat until all your oil is through.
Screw your lid on, label your oil (I use a label maker, but a marker and piece of masking tape will work just as well) and store in the aforementioned cool, dark place. until you need it for soap!