People get upset when you annoy them. Muscles get sore when you train too hard. But how does white cabbage become sour and turn into sauerkraut? Bacteria play a significant role in the making of this famous dish. To be precise, it’s lactic acid bacteria. Sauerkraut is produced through the process of lactic acid fermentation, a method known to many cultures for preserving vegetables. The prerequisite is a carbohydrate-rich (containing sugar molecules) food item, which is subjected to fermentation under oxygen exclusion at temperatures of 18-20 degrees Celsius.

Today, production is largely industrial in large containers. However, one can also make sauerkraut in Grandma’s stone crock at home. Here is how the natural, microbiological-chemical process of lactic acid fermentation works:

• First, remove the outer leaves and the core. Then, cut the cabbage head into fine strips.
• The prepared white cabbage is mixed with 0.8 to 1.8 percent salt, pressed, and sealed in a container as airtight as possible. Pressing displaces the oxygen, and cell juice is released
• The brine, containing carbohydrates, serves as a good nutrient medium for lactic acid bacteria, which do not thrive in the presence of oxygen. They are naturally present in the cabbage and, under favorable conditions, convert the sugar molecules into lactic acid. This process takes between six days and three weeks. During this fermentation, other substances such as acetic acid or carbon dioxide are also produced.
• Other microorganisms like spoilage bacteria are less comfortable in this acidic, low-oxygen environment, which inhibits their growth and activity.
• Throughout fermentation, aroma and flavor compounds develop. Most consumers find a lactic acid content of about one percent to be pleasantly mild and typically tangy.

Source: CMA