I started making my own pickles a few months ago. I bought a high quality fresh, refrigeration required for storage brand and when I finished them I had a huge amount of brining liquid left. I also had an older cucumber that I did not plan on using before it would have turned. I cut it into wedges and stuck it in the brine. I did this a few more times before it was time to dispose of the liquid. In hindsight when I think about this, it shows the exact purpose of brining or fermenting of food. Fermenting, which can be traced to at least 9,000 years ago, started as a way to produce alcoholic drinks. People then came to the realization that this was a perfect way to store food. If you want to see some old wines head to the University of Pennsylvania to see 7,000-year-old bottles of wine.
Fermentation in food processing uses yeast or other bacteria in a controlled environment, to convert carbohydrates to alcohol, thus preserving the foods. This obviously will change the flavor profile of the foods being preserved. The texture of the food items is also changed during this process. Vegetables are the most common foods that are fermented but fish and meats as well as beans are fermented often. Although this is a proven method to preserve foods there are some risks associated with it. Alaska is one of the biggest states that use fermentation due to the short growing season and the long and cold winters. Unfortunately, Alaska also leads the nation in cases of botulism, which is a big byproduct of improperly fermented foods. Fermented foods are also considered a carcinogenic food source, possibly leading to cancer. Having said that, one of the most famous fermented dishes in the world is Kimchi and studies have tied this dish and fermented fish dishes as one of the causes of a very high rate of stomach cancer in Korea.
Fermentation in food is mostly used to preserve foods but it also adds a lot of flavor and other characteristics to many foods. When you ferment foods you encourage growth of certain “good” microorganisms in it, while preventing growth of spoilage-causing microorganisms. When you are intentionally fermenting foods you may need certain equipment and a control of the environment where the fermentation takes place in. To avoid bad bacterial growth you need to control temperature and pH levels of the food. Here is how fermentation occurs and how it affects certain foods. For pickled vegetables the salt brine allows the growth of bacteria that eat the natural sugars and produce lactic acid. This acid works as a preservative for the foods that are brined. For wine, when yeast, either natural or added, are mixed with the crushed grapes the yeast eats the natural sugars and produces alcohol and carbon dioxide. Sweet wines come from grapes that have higher natural sugars so when the fermentation stops there are still sugars left in the wine. In bread when the yeast eats the sugar they produce carbon dioxide which gives the rise to the dough. The other main food item that has a need for the fermentation process is cheese. Bacteria in the milk, natural or added, eat the sugar lactose and reacts with the added rennet enzyme to curdle the milk. The whey, the liquid, is then drained off and the curds are compacted, dried further and then aged. Or in the case of cottage cheese the whey is drained but the curds are not pressed so some whey liquid remains.
Although with the negative effects mentioned earlier, fermented foods do have a lot of positive effects for people. Natural fermentation of foods has been shown to preserve nutrients and make the foods more digestible than in other forms. Another great byproduct of fermentation is the amount of probiotics that are created during the fermentation process. This is why the foods are easily digested. The problem with today’s fermented foods is that they are generally not done naturally, but using vinegar as the fermentation agent. Vinegar based fermented foods do not have the probiotics that naturally fermented foods have. Another reason we have lost a lot of our natural intake of probiotics is that dairy products such as milk and yogurt are all pasteurized, killing a lot of the probiotic micro-organisms and leading to a barrage of probiotic supplements for sale.
Besides the nutritional aspects of fermented food, fermenting of food also assists in the preservation of foods.