Making Neem oil is quite an old process that has been done for almost two millennia now. It began in India and Myanmar, where they grow Neem trees and use them for many different things.
The oil is acquired through an extraction process from the fruit of the Neem tree, a tropical tree that can reach up to 40m tall. These giants can live for up to 200 years, and they have abundant foliage all year round, capable of producing millions of fruits. There are various extraction methods, showing quire different results in as far as quantity and quality of the extract.
Neem extraction methods:
Compact extraction:
This is the method that gives the best quality oil due to the fact that no cuts are made, making for a 100% pure oil extraction. The method consists in crushing and compacting thousands of fruits. The traditional method is done with a kind of pot that has a filter underneath where the fruit shell sits, letting the oil drip through the bottom. Nowadays however, there are machines that can do the job easily, compacting the leftovers as if they were little bars, while the oil comes out of a different hole.
Hexane extraction:
Hexane is a hydrocarbon, transparent and extremely flammable that lets off an intense solvent smell. This system is much more modern and is done industrially; the result is lower quality neem oil but a much higher production.
Seeds are introduced into the machine and are compacted with hexane, releasing terpenes with a low molecular weight. The leftover seeds are tightly compacted and sold as what we now know as Neem press cakes, which still have a lot of properties but they’re less effective than the actual oil that is extracted.
Neem has been used for thousands of years in many indigenous medicines like Indian. It has loads of therapeutic uses like treating acne, fevers, malaria, tuberculosis, tetanus, hives, eczema etc. The World Health Organization recommends a reduced medicinal use as it can be highly toxic.
One of the main reasons that it’s been used for over two thousand years is due to its contraceptive properties, capable of stopping women from ovulating, although it can also cause sterility. It can cause major changes in reproductive organs in pregnant women, including deformations in the fetus and in some cases even death.
Used as an insecticide it’s one of the best products on the market, so much so that a lot of insecticides on the market contain Neem. Neem oil isn’t toxic to insects; rather it acts on their chemical and physiological processes. It stops them from eating and growing, which in turn causes them to die.
It also has some curious effects on insects’ protein and amino acid levels, causing their reproductive system to fail and therefore impeding the insects from spreading any more. It has quite a strong smell and it tends to keep insects away, although due to how strong it is you can’t spray it directly on your plants without using a surfactant (used to reduce surface tension) and the quantity of water indicated on the container.
Translation: Ciara Murphy