Stovetop Rosemary Oil
Utilize a substantial pot that heats up evenly. Avoid using any non-enameled cast iron or aluminum pots. Once you have placed the crushed Rosemary into the pot, you can gently pour in the oil. Place on low heat for about 5 – 10 minutes. You need the oil to warm however, not simmer.
Turn the heat off and allow the Rosemary to permeate the oil for at least an hour. Strain the mixture into a clean, dry glass container. Close the container tightly and store away from any direct sunlight or heat, preferably in a cupboard where it can sit, undisturbed, at room temperature for 2 months. Alternatively, you can place the container in your refrigerator for up to 6 months.
Making Rosemary Oil in a Slow Cooker
Set the fresh Rosemary into your slow cooker and then cover it with the oil. For one hour, allow the mixture to cook on the high setting.
After an hour has passed, you can then turn off your slow cooker and allow the oil to come down to room temperature. Strain the oil into clean and dry glass container and cover tightly. Store the oil away from direct sunlight or heat and allow it to sit at room temperature for at least 2 months. Or place it in your refrigerator for up to 6 months.