Siphon is an extraction method launched in 1830, but almost forgotten until today. Coffee making by this method gets really fancy and fascinating.
It is made with two glass cruets put one above the other with a filter in the middle.
Water for the coffee preparation will be put in the lowest cruet, which then will be placed on the specific burner. Gradually the water will heat, thanks to the pressure generated by the vapour, and will pass to the higher cruet.
When half of the water will be passed to the higher cruet, roughly ground coffee will be added by sprinkling and immediately stirred, in order to avoid burnings as the water will almost have reached the boiling temperature.
After the preferred infusion time, you will need to switch the burner off and wait for the coffee to percolate from the filter and return to the lower cruet.
Finally, now the coffee can be served.