An infusion is simply made by steeping herbs in oil or water to extract the soluble properties out of the herbs and into the liquid. This can be done by using either a cold or hot process. Making a cup of tea is an infusion.
In making infusions for soaps and lotions herbs are usually chosen for their known skin soothing properties. Calendula is a favorite choice here and the method most used is hot process.
Any oil may be chosen for infusion, the most popular mentioned seem to be olive and/or sweet almond oil, but you may want to use a recipe that doesn’t utilize these oils. Here, considerations are made based on what oils are in the recipe, the oil’s shelf life, along with the healing and moisturizing properties of the oil itself. Also, consider the recipe -do you want the highest percentage of oil in your recipe infused? Or maybe you would rather have just a touch of the herbal properties in your recipe? You may even want to blend oils for your infusion.
Even though exact potency of the end product isn’t known, notes are kept on quantities of ingredients used, time spent steeping and draining. This helps to give some consistency with batches made for recipes used repeatedly.
Herbs are placed in a crock-pot and enough oil to cover completely. Your mixture may swell slightly as it warms, so leave a bit of room to avoid overflow. Care must also be taken not to heat your mixture too high so you don’t cook away the benefits you are trying to capture. Don’t let your oils heat over 110°. If your crock-pot is able to heat the mixture higher than 110°, turn it off before it gets too hot and let the mixture steep. You may reheat and steep several times during your infusion period. A 24 to 48 hour period is considered sufficient time with heat extraction.
Once the infusion is finish, you need to drain the oil off the herbs. Pour mixture in a funnel or colander lined with a coffee filter or cheesecloth, letting gravity do the work. Stir the herb occasionally and surprisingly you will retrieve most of your oil. Store in a clean container and keep in a cool, dark place till you are ready to use.