Essential oils are highly concentrated oils extracted from aromatic plants like lavender and rosemary. There are around 700 plants that contain useful essential oils and there are several methods of extracting them, the most common being distillation. Although most essential oils are expensive to purchase, it is relatively inexpensive to distill them at home.
Steps
Part 1 of 3: set up the still to extract essential oils

Step 1. Buy an essential oil still
While it's likely that you're going to have a hard time finding a still in a store (unless you have a specialty store near you), it's easier to buy a still online. However, be aware that they can be quite expensive, usually between two and three hundred euros. However, if you want to brew large amounts of essential oils, a professional still is a good investment.

Step 2. Make your own still if you don't want to buy one
If you want to try making a still yourself, you can let your imagination run wild, because there are hundreds of designs out there, and even nowadays many stills are homemade. Here are the key things you need:
- a heat source, usually a direct flame,
- a pressure cooker,
- a 10 mm glass pipe,
- a tank filled with cold water to cool and condense the steam passing through the pipe,
- an essencier, which separates the essential oil from other materials that you don't want to find in the finished product.

Step 3. Prefer stainless steel or glass material
Do not replace glass tubes with plastic tubes, as this may affect the quality of the oil. Some plants react badly to copper, but you can use aluminum coated copper in most cases. You can also use aluminum material, but avoid it with wintergreen, cloves, and plants that contain phenols.

Step 4. Arrange the hose correctly
Bend it to pass it through the cooling tank. You will heat the plants in the pressure cooker and the steam that will emerge from them will pass through the pipe. You should be able to cool it down so that it becomes liquid again by immersing it in a bath of cold or ice water. Depending on the material you are using for your cooling pipe, you will need to bend the pipe in different ways. For example, if you are using a simple basin, you will probably have to bend it in a spiral shape so that you can see it put in the open basin. If you are using a bucket full of ice, you will need to bend the pipe 90 ° so that it can go through the top of the bucket and then through the drilled hole at the bottom.

Step 5. Connect the hose to the pressure cooker valve
Use a small piece of flexible rubber hose that fits tightly between the valve and the hose. Secure the end of pipe in place with rings purchased from a hardware store.
Make sure you keep enough pipe size for it to bend. Otherwise, your hose will end up straight up in the air and you will have to bend it 90 ° to direct it towards the cooling tank

Step 6. Route the hose through the cooling tank
If you are using an open basin, position it so that the spiral enters the basin. It should be completely submerged when you fill the basin with cold water or ice water. If you are using a bucket, drill a small hole in the bottom so that the hose can pass through the ice water. Seal the hole with silicone caulk or epoxy to prevent water from flowing.

Step 7. Position the open part of the pipe over the tree
Once the distillate begins to flow into the essencier, it will do the rest of the work for you. It will separate the essential oil from the rest of the material that you don't want in the final product.

Step 8. Check the still
Make sure that all of its parts are secure and do not move. Depending on the tools you use and the shape of your pipe, you may need to adjust the still a bit to make it stable and secure. Place the lid on the pot with the hose attached to it, pass the hose through the cooling tank and position the opening over the bowl. Make sure the pipe has an angle that allows it to stay in position and that nothing will fall on it.
Part 2 of 3: prepare the plants

Step 1. Determine when to harvest the plants
The amount of oil that is in the plant depends on its stage of growth, which is why it is important to harvest the different species at the right time. You need to do some research to know when to harvest the plants you want to distill. For example, lavender should be harvested for distillation when half of the flowers on the stem have wilted. On the other hand, rosemary should be harvested when the plant is at its peak flowering.

Step 2. Harvest the plants properly
Just as you need to educate yourself about when to harvest plants, you also need to research how to harvest them. You could reduce the quantity and quality of your essential oils by handling plants incorrectly, harvesting the wrong parts of the plant, or even harvesting them at the wrong time of day. For example, you should only use the flowers of rosemary for distillation. You can throw away or use the rest however you like.
Most essential oils are contained in the plant's oil glands, veins and eyelashes, which are very fragile parts. If you disturb or break them, you will get less oil from these plants. Handle plants with care and touch them as little as possible

Step 3. If you buy the plants, choose them carefully
If you buy plants that have already been harvested, you have little control over how they were harvested. Pick plants that look healthy and whole, and ask a vendor when they were harvested. In general, you should choose whole plants (that is, one that has not been crushed or powdered) instead.
Even though distillation removes a lot of impurities, pesticides and herbicides can contaminate your oil. It is best to use organic plants, which you buy or grow yourself

Step 4. Let the plant dry
By drying the plant, you decrease the amount of oil it contains, but it also allows you to extract more essential oil per batch. You should let them dry slowly and away from direct sunlight. Commercial plants like lavender or peppermint should dry out where they were cut for about a day.
- The ideal drying method varies depending on the plant, but in general you shouldn't overheat the plant. You will reduce oil loss by drying plants in the shade or even in a dark room.
- Do not let the plants get wet before distillation. Distill them as soon as possible once they are dry.
- If you prefer to skip this step, it is possible not to dry the plants.
Part 3 of 3: distilling the essential oil

Step 1. Pour the water into the still tank
If you've made your own still, the pressure cooker works as a reservoir. Use clean water, preferably filtered or distilled and as gentle as possible. If you are using a professional still, follow the instructions for use. Otherwise, you just need to make sure you have enough water to complete the distillation. Depending on the plant and how much you have, distillation can take anywhere from 30 minutes to 6 hours after bringing the water to a boil.

Step 2. Add the plants to the water
Place as many plants as possible in the tank. As long as you have enough water to boil the plants for the correct amount of time, there should be no problem with your plants, even if you have packed them well in the tank. Just make sure they don't block the steam outlet at the valve. Leave a few inches of space on top.
It is not necessary to cut or prepare the plants. In fact, you may lose oil if you prepare them

Step 3. Bring the water in the pressure cooker to a boil
Close the lid so that steam can only escape through the valve through the hose. Most plants will release their essential oils at 100 ° C, the boiling point of water.

Step 4. Keep an eye on the still
After a while, the distillate should start to pass through the condenser to the separator. You shouldn't have to watch the still during this step, but you should make sure there is enough water. Depending on how long it takes to distill the plants, you may need to change the water in the cooling tank. If the hot pipe heats the water, replace it with cold water or ice to keep the steam cool.

Step 5. Filter the oil you have collected (optional)
Once the distillation is complete, you can choose to strain the oil through cheesecloth or similar cotton cloth. Make sure the fabric is dry and clean, as laundry residue and grime can contaminate your oil.
Don't be disappointed if you only get a very small amount of essential oil from a large amount of plants. The percentage varies by species, but you will always have less of it than the novice distiller thinks

Step 6. Very quickly pour the oil into the storage container
You can store most essential oils for at least a year or two, but some have a shorter shelf life. To increase the life of your essential oil, store it in an opaque glass bottle or in a stainless steel container. Use a clean funnel to pour the essential oil into its bottle, and make sure the bottle is clean before pouring the oil in. Then store it in a cool, dark place.
- Think about what you want to do with the hydrosol. The liquid that remains in the essence is hydrosol, water that has been distilled and infused with the scent of the plant.
- You can use certain hydrosols, such as rose or lavender.
- If you don't want to keep the hydrosol, you can pour it back into the tank if you want to distill another batch of plants. Otherwise, you can throw it away.
Advice
- Essential oils are extremely concentrated and it is often advisable to dilute them in a carrier oil before applying them to the skin. The most commonly used carrier oils are almond oil and grape seed oil, but you can use several varieties of vegetable oils. You can add them when pouring the essential oil into the bottle or you can mix them with the essential oil before using it. It is better to use the latter solution, as carrier oils often have a shorter lifespan than essential oils.
- To separate the oil and water, you can put the product in your refrigerator, the oil will solidify slightly, a bit like butter, which will make your job easier.
Warnings
- When drying the plant, be careful not to contaminate it with dirt, dust, or other contaminants. This contamination will reduce the quality of the oil and could render it unusable.
- Most essential oils should not be ingested, especially if they are not diluted and many of them need to be diluted before applying them to the skin. See the links in this article for more information.
- For the distillation of most of the flowers, you should avoid letting them dry out and you should distill them immediately after harvesting them.
- Organic does not mean that the plant has not received pesticides or fertilizers, but that it has received different ones, generally less toxic than pesticides and synthetic fertilizers. Try to find a grower near you who can tell you how the plant grew.
- Do not distill a batch of plants for too long (check the recommendations for the plant in question), as this will add a trace amount of oil, but will contaminate your oil with unwanted chemicals.