Conching machine
The conching , even briefly Conche called (from the span. Concha , shell , because of the original shell shape of the trough) is, in the production of chocolate a special kneading and stirring device that makes the melting character of the final product possible.
invention
In 1826, the Swiss chocolate manufacturer Philippe Suchard invented the mélangeur - a machine for mixing sugar and cocoa powder. In December 1879, the Swiss chocolate manufacturer Rudolf Lindt achieved a decisive improvement with his invention of the conche: the previously common brittle, sandy consistency of commercial chocolates, bitter in taste and by no means melting on the tongue, was given the fine, creamy, melt-in-the-mouth structure that is still valued today.
Mode of action
The resulting mass after mixing the ingredients ( cocoa butter , cocoa mass , sugar , milk powder ) in the Mélangeur (mixer) is quite dry with two to four percent residual moisture, but still contains enough water that the dissolved sugar partially crystallizes again and the structure changes the mass strongly fissured. The smoothing fat content of the cocoa butter disappears in the countless tiny crevices. The chocolate mass looks crumbly, almost floury.
Rodolphe Lindt knew that he had to extract more moisture from this chocolate mass in order to prevent the sugar from crystallizing. He constructed a mixer, a so-called “longitudinal grater”: a flat, elongated basin made of granite , over which granite rollers move back and forth. The resulting friction heats the mass in the container to between 76 ° C and 78 ° C, making it liquid. The rollers hit the edges so that the chocolate essence sloshes back over the rollers into the main part of the mechanism and the residual moisture drops to less than one percent through evaporation .
It is not known whether Lindt is experimenting with longer running times of his machine or simply forgetting to switch it off. In any case, the result after 72 hours of stirring in the conche was astounding - Lindt found something completely new: a matt, glossy, liquid mass that was easy to pour into molds, had a wonderful aroma and, above all, melted on the tongue.
With modern conches, conching only takes about 12 to 48 hours with the same good result. Semi-continuous high-performance conches (PIV) have been in operation worldwide for several years. These machines work with a significantly higher shear gradient than traditional conches and can thus complete the entire conching process in about an hour with the same good quality.
Refinement of the taste
Not only water, but also odor, bitter and aroma components evaporate through long conching. The taste of chocolate is so positively influenced. By pretreating the cocoa mass used separately, the water and a large part of the undesirable flavoring substances can be removed in advance. In this way, the required conching times can be shortened significantly.
However, not all chocolate consumers want this change in taste, because long conching also loses the flavoring substances that give chocolate its characteristic aromas. In contrast to what is often advertised by the product marketing of the chocolate industry, no conclusions can be drawn about the product quality from the duration of the conching process.
Further development
The process, which was continued in 1899 after the Lindt company was sold to Chocolat Sprüngli AG ( Zurich ), was published in the specialist press in 1901 despite being kept secret and has since been adopted by other manufacturers worldwide.
With improvements one tries to shorten the process and to control it better. While Lindt's Ur-Conche only heated by friction, it was heated later with steam and hot water. The heating process, the temperature profile and the final temperature reached (55 to 90 ° C) are now part of the recipe, because they influence the taste of the chocolate as well as the duration of conching. The skill is to control the temperature so that undesirable flavors evaporate, but not desired ones.
Some chocolates are conched for up to twelve hours, others for up to three days. Since longitudinal rubbers can hold a maximum of 1000 kilograms and require a lot of energy and time, they are considered obsolete and uneconomical. Today round conches are mostly used, which move up to nine tons of chocolate mass in a circle with rotating arms. There are now several designs and techniques that are used in an attempt to streamline the time-consuming process of conching. Depending on the type of machine, the end product will have completely different taste nuances with the same raw material composition.
Web links
Individual evidence
- ↑ Chocolate pioneers: Philippe Suchard , swissworld.org ( Memento of April 17, 2015 in the Internet Archive )
- ↑ Chocolate pioneers: Rodolphe Lindt , swissworld.org ( Memento from December 23, 2014 in the Internet Archive )
- ↑ Comparison of conching ( Memento of April 12, 2009 in the Internet Archive ).
- ↑ Conching Chocolate Chclt.net.