Making essential oil by steam distillation

In this blog we will explain step by step how you can make essential oil yourself. What is a common thought among people is that essential oil can be made by, for example, soaking a few sprigs of lavender in vegetable oil or alcohol. However, this is not the case. Making essential oil can be done in several ways:
– Pressing, press the thin peel of the citrus fruits (zest) together so that oil is released;
– Co2 extract, high pressure extraction with carbon dioxide;
– Steam distillation.
In this blog we will only discuss the process of steam distillation.

Steam distillation can be done using a copper column still, see image below:

It is wise to weigh the plant material before the distillation process, so that you can calculate the yield of essential oil after distillation.

Fill the copper kettle with hot water and put the plant material in the column. The plant material must be pressed firmly so that there are no more visible holes between which the steam can escape. Then place the hat on the column of the still and connect it to the cooling bucket. It is very important that no steam can escape between the seams of the still during distillation. You can make the seams leakproof with aluminium / Teflon tape.

Then you must attach a (garden) hose to the cooling bucket and attach a (garden) hose from the cooling bucket to a drain. You can cut in the garden hose at the end so that it can be secured to the cooling bucket with the hose clamps. The water in the cooling bucket should be allowed to flow slowly.

When the setup is all right, the distillation process begins. The water should be heated to 100 degrees. The steam will end up in the spiral of the cooling bucket via the plant material. The water in the cooling bucket must not be too cold during the distillation process, otherwise the oil will stick to the walls of the cooling coil. Then the hydrosol and the essential oil come out of the spiral of the cooling bucket. You can collect the hydrosol and the essential oil with a separatory funnel. This allows you to easily separate the hydrosol and the essential oil during the distillation process.

When the still is used for different purposes (for example making liqueur) or for making different essential oils, it is necessary to clean the still well after use. You can do this by pouring cheap white wine into a still instead of water. You then repeat the distillation process. After use of the still, it must be stored in a dry place, so that it does not oxidize. Below we have described the most common plant materials used in steam distillation.

Lavadula intermedia ‘Grosso’, a fragrant lavender with blue-green leaves and violet-blue flowers. The lavender is best planted in a sunny and somewhat dry spot in the garden. The harvest time is in the months of June and July, when the lavender is 50% in bud and 50% in bloom. It is recommended to prune the lavender plant by two thirds. The average yield of the essential oil is 7% of the total distilled plant material.

Lavendula angustifolia, a fragrant lavender with white-grey leaves and purple flowers. The lavender is best planted in a sunny and somewhat dry spot in the garden. The harvest time is in the months of June to August, when the lavender is 50% in bud and 50% in bloom. It is recommended to prune the lavender plant by two thirds. The average yield of the essential oil is 4% of the total distilled plant material.

Rosemary, a wonderfully aromatic herb with blue flowers. The Rosemary is best planted in a sunny and sheltered spot in the garden. The harvest time is in the months of June to August, when the flowers are on the rosemary branches. The leaves as well as the branches and flowers are used for the distillation process. The average yield of the essential oil is 1-2% of the total distilled plant material.

A good time to keep an eye on harvest time is when you see the bumblebees and bees flocking to the plant at the same time. It is wise not to harvest until after there have been several warm and sunny days.

Scots pine, Douglas fir and Larch, conifers that grow in wooded areas. The coniferous trees are harvested in May when the suckers are on the trees. To preserve the forest, only the side branches are pruned. The branches must first be made smaller by a chipper. The average yield of essential oil after distillation is 0.25% for Scots Pine, 0.5% for Douglas fir and 0.1% for Larch, from the total distilled branches. Scots pine and Douglas fir have to be distilled twice because of the wax coating on the branches. Here too, it is recommended to only harvest after a few sunny days, because this increases the yield of the essential oil. Distilling twice means that you put the distillate that comes out of the coil of the cooling bucket back into the kettle and heat it again.

We hope that by now you have become enthusiastic about making your own essential oil. Here you can find a copper column still and a separatory funnel to get you started.