Dried or fresh herbs are used to make heat infused oils.  Depending upon the herb, they may be used in remedies such as ointments, or as culinary oils.  Any plant parts can be used but this method is particularly useful for extracting oil-soluble ingredients from dried roots.  The method is far quicker than that for cold infusion as the herbs are simmered in the base oil and there is less likelihood of microbes entering the oil during fabrication. Jars and bottles do need to be carefully sterilised however.  As with the method for fresh herbs, there is no need to measure accurately or produce vast quantities of infusion but it is wise to record how much herb and oil you use, for future reference. Heat infused oils should last for about a year but they are best used within 6 months.

The photos show dried wild crafted Calendula being infused.
I used 50g Calendula with about 600ml olive oil for this infusion.
It yeilded about 560ml of infused oil.  That’s enough to make a about 8 – 10 salves.  With denser herb material far less oil would be required.

Materials:
Heatproof glass bowl and saucepan, set up as a Bain Marie (or use a double boiler)
Dried herb – chopped
Vegetable oil (olive oil is my preference but you may like to try coconut oil, almond oil, peach kernel oil)
Wooden spoon or chopsticks
Jelly bag, muslin or tea towel.
Jug
Sterile storage bottles and lids or corks

Method:

1. Place the chopped herbs into the glass bowl.
2. Cover them with oil; enough to form a 2cm clear layer above heavy herb material such as chopped roots, or enough to allow the herb material to move around in the oil, if using light material such as petals.
3. Heat the bain marie until the water is boiling and then simmer gently, with a lid over the glass bowl, for about 2 hours.  Stir the oil-herb mixture from time to time and check that the pan does not boil dry.
4. Remove from the heat and allow the oil-herb mixture to cool enough to handle comfortably.
5. Pour through the  jelly bag or cloth, into a clean dry jug.
6. Squeeze, wring and press out as much oil as possible, through the jelly bag.  It helps to wear rubber gloves for this stage.*
7. Pour into sterile dry storage bottles or jars (preferably dark glass).
8. Seal with screw caps or tightly fitting corks.
9. Label and store in a cool place.
10. *After making infused oils, I sometimes hang the jelly bag under the bath tap and fill the bath through the “used” herbs. Of course this is only suitable for some of the herbs, Chamomile and Calendula are particularly suitable.