How to Make Essential Oils
Essential oils are highly concentrated, volatile oils that can be extracted from aromatic plants. Their use dates back to ancient times, and their wide variety of therapeutic, medicinal and culinary uses has ensured their continued popularity. About 700 different kinds of plants contain useful essential oils, and the most common method of production is distillation. While essential oils can be very expensive to buy, they are relatively cheap to distill at home. This guide provides basic instructions on how to extract the oils using the relatively simple and effective water-and-steam distillation process.
- Obtain a still
(the apparatus used for distilling). You
can purchase one specially designed for
distilling essential oils; these
generally cost several hundred dollars
or more, but if you plan on doing a lot
of distilling and you're not
particularly mechanically inclined, this
is probably the way to go. The key
components of a still are:
- The heat source or furnace, which is used to boil the water. Direct fire, a fire built under the retort is the oldest method for heating the still. Today, we can also use gas, such as propane or butane, and electricity. Fuel costs are a major factor when considering a heat source for you distiller;
- The holding tank or retort, which holds both the water and, just above the water on a grate or false bottom - picture a vegetable steamer - the plant material to be distilled;
- The condenser, which collects the steam and cools it, usually by piping it through a tube immersed in cold water, and...
- The separator, which separates the essential oil from the water vapor. The separator, or Essencier, is one of the most important pieces of apparatus a distiller can have. This enables the distiller to separate the essential oils from the distillate in a passive manner.
- Harvest your raw material. The quantity of essential oils contained in a plant varies over the course of the plant's development, so it is essential to harvest at the right time. This will depend on the type of plant, so you need to do some research to determine when to harvest. It is also critical to harvest the plants correctly - careless handling, harvesting the wrong parts, even harvesting at the wrong time of day can reduce the quantity and quality of the essential oils. Again, research the plant you wish to distill. If you're buying harvested material, you don't have much control over the harvesting process; look for plants that appear healthy and undamaged, and ask the seller when they were harvested. Generally plants that are in whole form (not crushed or powdered) are best.
- Dry the plant material. Drying reduces the amount of oil in each plant, but can greatly increase your yield per batch because you will be able to fit more material into each batch. Drying should be done slowly and NOT in direct sunlight. You can choose not to dry your plant material. Commercial plants such as lavender and peppermint may be allowed to dry in the field after cutting for a day or so. The ideal drying method varies from plant to plant, but in general you should not overheat the plants - drying in the shade or even in a dark room minimizes the oil lost - you should not over dry them, and you must not allow the plants to become wet again before distillation. Distill as soon as possible after drying.
- Add water to the tank of your still. Use clean water, ideally filtered or distilled and as soft as possible. If you're using a manufactured still, follow the manufacturer's direction. Otherwise, simply make sure you have enough water in the still to complete the distillation; depending on the plant and on the quantity, distillation can take anywhere from a half-hour to six hours or more after the water boils. Be sure that the water level is close to, but not touching, the false bottom that will hold the plant material. If you are performing a hydrodistillation (this is useful for delicate flowers or powdered roots, bark or wood) You will need to have your plant material free floating IN the water.
- Add your plant material and pack it tightly in the still. You do not need to chop or cut the plant material, and doing so will cause you to lose some of the oils. The plant material should rest on the false bottom or grate above the water and should touch the sides of the still as little as possible. The layer of plant material can be quite thick as long as it is below the steam outlet (a couple inches below the outlet for a small still, a foot below for a large one).
- Close the still and boil the water. Most plants will release their essential oils at 100 degrees Celsius or 212 degrees Fahrenheit, the normal boiling point of water.
- Keep an eye on the still. After a while the distillate should begin to come through your condenser and into your separator. The process should be fairly hands-off, but you will want to ensure that you do not run out of water in your still. Depending on the length of the distillation process, you may also need to change the water in the condenser so that the cooling process continues to work. Follow the instructions for the particular plant you are distilling.
- Filter the collected oil (optional). Once your distillation is complete you may filter the oil through cheesecloth or similar dry cotton fabric. Ensure that the cloth is dry and clean - detergent residues as well as dirt can contaminate the oil.
- Pour the oil into a container for storage. Do this as quickly as possible. Most essential oils can be kept for at least two years, but some have extraordinary shelf lives. To maximize the useful life of your oil, keep it in a dark glass bottle or stainless steel container. Use a clean funnel to pour the oil into the container, and make sure the container is impeccably clean before pouring the oil into it. Store in a cool, dark place.
- Decide what to do with the hydrosol. The distillation process produces the essential oil and a hydrosol, the term for the water that has been distilled and which collects in the separator. Some hydrosols are usable themselves - rose water or lavender water, for example. If you do not wish to save the hydrosol you can pour it into the still for the next batch (if you will be distilling another batch immediately) or you can discard it.