The cannabis contains around 5% THC (tetrahydrocannabinol), the psychotropic substance of the plant with therapeutic properties.
The inflorescences are separated from the stems and leaves – painstaking, tedious work that is done by hand.
After the work is finished, only a quarter of the original 150 kg cannabis crop is left.
The approximately 40 kg of crushed cannabis flowers are kept in a refrigerator.
The cannabis flowers are poured into a 70% alcohol solution.
To remove the THC and other cannabinoids, the solution is stored for at least half an hour at room temperature, and then filtered.
This procedure is repeated two to three times.
The objective is to obtain a solution containing 10 mg of THC per millilitre.
Out of 40 kg of cannabis flowers, around 120 litres of tincture can be produced.
Each production step is standardised and all data are recorded.
The cannabis tincture is then sold in pharmacies.
Chemist Markus Lüdi is Switzerland’s only producer of a natural tincture made from cannabis. In his laboratory in Burgdorf in canton Bern he demonstrates how a liquid drug can be produced from cannabis flowers. (Photos: Thomas Kern, swissinfo.ch)