This process was developed in the USSR for soviet sparkling wine and is now used in Germany and Portugal. but only for large-volume inexpensive fizz. The method involves a series of usually five reticulated tanks under five atmospheres of pressure, the same fizziness as in most sparkling wines. At one end, base wine together with sugar and yeast (usually rehydrated dried yeast) is pumped in and the second fermentation crucial to virtually all methods of sparkling winemaking begins. This creates carbon dioxide, which increases the pressure in the tank, but the yeast cannot grow under this pressure and so further yeast has to be added continuously. The second and third tanks are partly filled with some material such as wood shavings, which offer a substantial total surface area on which the dead yeast cells accumulate and a certain amount of autolysis, or at least reaction between the dead yeast cells and the wine, takes place. In the fourth and fifth tanks there are no yeast cells and the wine eventually emerges relatively clear, having spent an average of perhaps three or four weeks in the system. See also lancers.