Each spring we celebrate the firing of the charcoal kiln in Ittingen forest.
The History of Charcoal Making
Since ancient times until the 19th century charcoal was used for smelting metals. Charcoal consists almost exclusively of chemically pure carbon, thus creating much higher temperatures than wood when burned. These temperatures were necessary in order to generate sufficient heat in the simple furnaces of old.
Smiths would also use coarse charcoal to heat their meals, and finer charcoal was used by nail makers. Over time charcoal came to be appreciated in private households for heating flat irons or water. Even today charcoal is used by goldsmiths and copper smiths.
In former days wood was turned into charcoal there and then when transporting it was too difficult. This was practiced in all larger forested areas in the Jura, the Lower Alps and in the Alps. The charcoal burners lived in remote forests, often in inconceivably simple circumstances. As they did not come in contact with other people for several weeks, it is not surprising that some of them turned into true recluses.
Old maps and some maps still in use today show that in many communes there are topographical names referring to the old craft of charcoal burning, such as Cholgrueb, Cholplatz, Cholholz, Choltobel or Pächloch. Cholgrueb and Pächloch indicate that wood was not only charred in mounds but also in pits. As one needs water to produce charcoal, piles or pits were always located near a stream.
Charcoal was also produced in Ittingen. Not far from the former monastery there is a place called Kohlhütten, which was still mentioned in the official survey of 1980, but has since disappeared.
Charcoal burning declined in the 19th century when stone coal gradually replaced charcoal, and gas and electricity gained in importance. World War II triggered a new but short-lived demand in charcoal in Switzerland. In 1944, 14,000 automobiles were apparently fuelled with wood or charcoal.
Today the only Swiss charcoal piles still regularly in use are located in the Entlebuch, as well as in the open-air museum Ballenberg.
‘Meiler’, the German word for charcoal pile, derives from the Latin word mille for ‘thousand’. It developed into the loanword ‘Meiler’, which can be translated as ‘large number’ – in this case a large number of piled wood.
Constructing a Charcoal Pile
The charcoal pile in Ittingen forest, which is built every year, consists of about 30 to 50 stacked cubic metres (steres) of high-quality beechwood logs. Charcoal production requires a level area protected from the wind. Wind is a dreaded factor in charcoal production, and water is always in high demand. A grate placed on the ground ensures sufficient air supply. The combustion shaft in the middle consists of either three to four poles connected to each other, or, sometimes, of wood pieces arranged in a special order, called Füllihuus or Quandelschacht.
So as to guarantee even burning, the wood pieces are stacked as tightly as possible. Small pieces of wood are used to fill in any uneven areas on the surface. It is easier to cover the pile when the surface is smooth and compact. First, the charcoal burner puts a layer of either fir brushwood, leaves or grass directly onto the wood. This layer separates the wood from the actual coat, which consists of soil mixed with charcoal waste from old piles called Löschi. This outer layer has to be fire-resistant, practically air-tight, pliable and permeable for water vapour. Placing the damp ‘Löschi’ on the pile is heavy manual work.
To start the wood carbonisation process, burning charcoal pieces are poured into the ‘Füllihuus’. About eight hours later, the shaft is closed off with a metal plate. The fire starts to smoulder inside the pile. Carbonisation extends like a funnel from the inside out and from top to bottom. Once the charcoal kiln has been started (Anfahren), the charcoal burner will have to be present 24 hours a day for about ten to twelve days, the pile requiring work every two to three hours.
How Wood Carbonisation Works
When the temperature has roughly reached boiling point, the pile first emits water vapour before the wood starts to disintegrate and volatile substances are expelled. In the centre of the pile the temperature can reach up to between 300 and 600 degrees.
The charcoal burner manages the process by controlling the air supply via the ventilation holes near the base. So as to enable water vapour and smoke to escape and prevent the pile from exploding, the charcoal burners bore holes into the pile’s outer layer. They are as thick as a broom stick and run all along the pile, from top to bottom. White smoke rich in water vapour escapes through these holes. If the smoke turns blue or transparent, this is an indication that the carbonisation process is complete and the holes must be sealed. New air holes are punched two hands’ breaths further down. While this is happening, the pile shrinks to half its original size. When the carbonisation process is complete, all holes are closed in order to extinguish the embers.
The big moment has come: the coal is spread out with rakes, brought to an empty place for cooling, and finally filled into paper bags.
Ittingen charcoal, which is particularly suitable for barbecues, is available at Kartause Ittingen’s monastery shop.