A control arrangement for a two-stage submerged vinegar fermentation process for producing vinegar with a high acetic acid concentration of more than 15% is disclosed. The fermentation system includes a main fermentation tank and a secondary fermentation tank, a connecting line with a shut-off valve and a feed pump incorporated therein extending between the two tanks, separate mash and alcohol feed lines with incorporated feed pumps connected to the main fermentation tank, and a vinegar discharge feed line with an incorporated feed pump connected to the secondary fermentation tank. The control arrangement includes an alcohol analyzer and a liquid level sensing device on each of the tanks, a volume flowmeter incorporated in the alcohol feed line, and a controller for each of the tanks. The control connections are such that alcohol is charged into the main fermentation tank in dependence on the alcohol concentration therein, substrate is discharged into the secondary fermentation tank from the main fermentation tank in dependence on the quantity of alcohol charged into the latter, with the transfer being terminated when the liquid in the main fermentation tank reaches a preset lower level, and vinegar is discharged from the secondary fermentation tank in dependence on the alcohol concentration therein having decreased to a predetermined minimum, with the connecting line between the tanks being blocked until the liquid in the secondary fermentation tank has fallen to a preset lowest level.