Food preservation is the science of preserving food by canning, fermentation, drying , salting and drying. Canning high-acid foods such as jams, jellies, fruits and pickles is easy and can be processed in a water bath canner. With a variety of pectins available, the process can be fast and is very safe.
Canning low-acid foods such as meat, poultry, fish and vegetables requires more knowledge and must be performed in a pressure canner. If metal cans are selected a can sealer is needed to close the containers. The glass jars are the easiest container for using at home, however, most products are canned in metal containers what can be verified in any supermarket.
Cabbage contains enough sugar and lactic acid producing bacteria for successful fermentation. The majority of problems associated with sauerkraut production can be traced to the Insufficient knowledge of the process and poor selection of the equipment.
Water channel fermenting clay crocks or glass fermenting jars are wonderful devicesfor making sauerkraut. Both devices operate on the air-lock principle and both will produce outstanding sauerkraut. An airlock is a little plastic device holding a small amount of water which physically separates the inside of a fermenting vessel from the outside air. It acts as one way valve: it allows the air to leave the glass jar, but prevents the outside air from entering the jar. The air-lock has been used in wine making for centuries.
Fermenting bacteria produce lactic acid and carbon dioxide (CO2 – soda gas). The raising pressure of CO2 starts to push the air out of the jar. (The air is light and accumulates above the sliced cabbage). CO2 is heavier than air so it resides on top of the cabbage below the air. As CO2 expands in volume (bacteria keep on producing it) it starts to push the air through the air-lock. The excess of CO2 will escape as well. After some time, the layer of CO2 settles down on top of the cabbage (which should be submerged in brine), and any remaining air will be above.When the pressure increases again, the cycle repeats itself. Now, the fermenting cabbage is physically separated from the air and this eliminates the main nuisance of sauerkraut making – the molds. Molds need air to survive, removing air prevents molds from growing and eliminates slime.
Fermenting 1 gallon glass jars.
Fermenting 6 gallon bucket.
Fermenting clay crocks.
Fermenting water channel clay crock works on the same principle. Detailed description.