Introduction: Essential Oil (Solvent Extraction)
If you are anything like me, you would most definitely adore the fresh, stark fragrance of thyme or the sobering whiffs of sage and an easy, cost effective way of capturing these fragrances is to extract them yourself.This instructable is designed to demonstrate and instruct on the solvent extraction of essential oils and fragrances from plant matter. the products of this extraction can be used in perfumes, cooking, and even aromatherapy.
Step 1: Materials and Apparatus
- An organic solvent (e.g food grade ethanol, if consumption is intended) I used Acetone
- A whole lot of Plant matter(e.g peppers,cinnamon, rosemary, sage, basil, thyme,etc.)
- Beaker/ Mason jar
- Coffee grinder or blender
- Filter paper
- Paper towels
- Baking sheet
- Hot plate
- Mesh strainer
Step 2: Leaf Dehydration
- Thoroughly wash the freshly picked herbs, removing dirt and debris.
- Spread leaves on paper towel to allow to dry completely.
- Place the leaves onto a baking sheet and place into the oven or a dehydrator at 180°F/82.2°C.
NOTE: High temperatures can cause oils to aerosolize, hence diminishing yields.
- leave thee leaves for about 2-4 hours or until they are completely dehydrated (can crumble easily).
Step 3: Leafe Disnitegration
During this step, we take the leaves and chop them up into a powder or flakes. This step optimises the process as it increases the surface area of the leaves and hence exposing more plant matter with the oils to the solvent. The solvent can now easily dissolve more oils.
- Place the leaves into a coffee grinder or blender and pulse until the desired particulate size is achieved.
- Empty fragmented leaves in to the extraction vessel.
Step 4: Solvent Extraction
For this step i used a 1:2 ratio of plant matter to solvent
- Place the allotted amount of solvent into the extraction vessel.
- Stir or shake continuously for anywhere up to an hour.
- To optimize this extraction, the suspension can be left for extensive periods of time, in addition to introducing to a low heat (below the boiling point of the solvent). This allow more oils to dissolve into the solvent.
Within the leaves and other plant matter, there are oils and other aromatic substances that give the extract its distinctive scent. the solvent's purpose is therefore to extract the desired compounds by dissolving them into solution.
Step 5: Filtration
During this step, we will attempt to achieve the lowest visual particulate count for the solution.
Filtration and decanting would result in cleaner oil samples.
- Decant the suspension into a mesh strainer, removing heavy fragments.
- Pour the filtrate into a coffee filter.
- Repeat these steps if necessary.
- Wash leaf matter and filter paper in a little solvent.
NOTE: to remove the chlorophyll from the solution, the solution can be placed under a bright light or in the sun in a caped container to prevent excess solvent loss.
Step 6: Evaporation
NOTE: THIS STEP SHOULD BE DONE IN A WELL VENTILATED AREA AS THE INHALATION OF VOLATILE ORGANIC COMPOUNDS ARE KNOWN TO CAUSE HEALTH COMPLICATIONS.
- Place the filtrate onto a hot plate. a water bath can be used if the vessel is not heat competent.
- Set the hot plate to the appropriate temperature which facilitates the boiling of the solvent, stir continuously.
- Placing a fan to blow across the surface of the solution will decrease the time needed for complete evaporation.
- Stop the evaporation process when the solution begins to thicken and/or when the pungent scent of the solvent is minimal.
- Step 1-4 is completely optional and dependent on the amount of solvent used.
What occurs during this step is, the solution of our extract and solvent is being separated. the solvent evaporates, leaving behind oils and other compounds.
Step 7: Bottling & Storage
- The essential oils/extracts should be stored in a dark, air-tight bottle and in a cool place, as heat, light and air are known to degrade the quality of the oil/extract.