Simply soaking herbs in oil isn’t enough to infuse the oil; it needs to be heated. Luckily, there are a few ways of doing this so you are sure to find one that suits your needs. The following describes how to infuse oils using the stovetop, a slow cooker, or the sun!
The common thread to all methods is to pack as many dried herbs as you can fit into a container, and then pour over the oil so that the herbs are completely submerged. Choose herbs that are completely dry (moisture and oil don’t mix). When the infusing is finished, strain the herbs from the oil with a fine sieve once, then pour the oil through a coffee filter or cheesecloth-lined fine sieve. Store the oil with a tight-fitting lid in a cool, dark place.
Generally, infused oil will last up to the best before date on the original package label. Olive oil should last for 2-3 years and coconut oil will last for many years, although spoiling could happen more quickly if contaminants were introduced in the infusing process.
Stovetop Oil Infusing
Use a double boiler to slowly heat the oil and herbs. Pack a handful of herbs in the top of a double boiler, and pour oil over. If you are using coconut oil, which is solid at room temperature, then melt the oil first before adding the herbs. Fill the bottom pot with an inch of water and set the double boiler on medium-low heat to warm up, then turn down to low for a few hours or until the oil becomes aromatic.
Slow Cooker Oil Infusing
The slow cooker method takes longer but it requires less attention than the other methods. Just set it and forget it! If you have a small slow cooker, or you are doing a large amount of oil, you can add the herbs right into the ceramic bowl and set it on the lowest setting for 8-12 hours.
Note: When making her herbal oils in a crock pot the biggest thing to watch out for is condensation from the lid of the crock pot. If condensation drips into the oil, then it can introduce mold and bacteria. If you’re putting the oils and herbs directly into the crock pot then leave the lid off while you infuse the oils.
To do a number of different herbs in separate oils, you can put the oil/herb combination in mason jars and set those in the slow cooker. Put a lid on each of the jars and leave the lid off the slow cooker. Infuse for the same timing: 8-12 hours on low.
Pack herbs into mason jars and pour oil over them. Screw on a lid and set in the sun for 8 hours. The summer sun can be very hot, so this method is best used in cooler months and with large jars. Overheating the oils can remove some of the beneficial properties and this method is one you will have to watch more closely. It doesn’t use any power beyond the sun so you can infuse oils right out in the garden as you harvest your herbs!