I love spending the summer wandering the land, observing, gathering herbs and infusing them in oil or grain alcohol to extract and preserve their glorious medicinal properties. Throughout the fall, I start to filter and remove all the herbs from the menstrum (solvent that is used to extract the medicinal properties of the herb).  Although I’ve written quite a bit about herbs and processing them, it has come to my attention that people would like more information on filtering herbal infused oils. So, I thought I would share my method based on numerous evolutions of filtering herbs.

The primary goal is to remove all plant matter and sediment so the oil is crystal clear. Depending on the method you choose, you may have to filter it two or more times.

At the beginning of my filtering journey, I was a big fan of squeezing out every bit of oil I could (hey, it was very valuable, I didn’t want to waste a drop); at first I used my hands and then I bought a press. The press was much easier and I was able to extract quite a bit more oil. I was thrilled, but I wasn’t done. There was quite a bit of sediment left over.

When filtering oil, the first step is to strain it through an unbleached cheesecloth or muslin lined stainless steel strainer. After the oil rests overnight, you will notice sediment at the bottom of the jar. Remember, the end product should be crystal clear, so you will need to filter it until all the sediment is gone. When using a press, a lot of sediment is leftover.

Nevertheless, I finally came up with an excellent way to filter oil and it only needs to be done twice. I line a stainless steel strainer with unbleached cheesecloth or muslin. Pour oil and herbs into it, then I put a weight (at least a pound) on top to help push the oil out.  I let it sit with the weight for at least an hour. Then I gentle squeeze the remainder of the oil out and stop when the oil starts to get cloudy. The oil rests overnight before I pour it through two layers of paper towels lining a stainless steel strainer. The result is a beautiful crystal clear oil, ready to be used.

Gently squeezing

After gently squeezing, the oil starts to get cloudy

The next step is to line a stainless steel strainer with an unbleached coffee filter or two paper towels (my preferred method). Filter the oil again and let the oil rest overnight. In the morning, check to see if there is sediment. If the oil is crystal clear without any sediment, you are done! It is best to store it in amber bottles and a dark cool place. However, what I have found is that if you really squeezed all the oil out or used a press ~ you will not be done. There tends to be too much sediment for the two-paper towel method, so you will need a single paper towel once or twice before the oil is ready to pass easily through two paper towels. For the most part, I was filtering the oil no less than 4 times before it was crystal clear. Although, I thought I was capturing as much valuable medicinal oil as possible, in reality, after four filters, I don’t think I really gained much.

Sediment left in jar after oil rested overnight

comparison

You may ask, “What is wrong with cloudy oil?” Well, the sediment left in the jar may be moisture and/or plant material that will increase the likelihood that your precious oil may go rancid ~ YUCK!  No one wants that! Especially after you’ve spent 6 weeks giving it lots of love and intention. Just filter all the sediment out.

Crystal Clear! You can see right through it.

Everyone has their own way of filtering herbal infused oils. There are many ways, this is just one way, my way; it simply makes sense to me. Experiment, research, and see what works best for you.