As a former biology teacher, I find invisible creatures fascinating. Germs! Virsuses! Bacteria! These little guys live everywhere and they have a range of characteristics. The most famous microbes are the ferocious ones that attack and kill even the largest of creatures.
But bacteria and other microbes are not all bad. Some mind their own business, not affecting our day to day lives, and some we cannot live without. Our skin secretes bacteria food to encourage the growth of specific bacteria, which crowds out harmful microbes. — In essence, skin is a bacteria farm.
A few strains of bacteria can play the character of both the good cop and the ax murder. For example, vitamin K, which is necessary for normal blood clotting, is produced by bacteria living in our gut. These helpful bacteria are no other than the infamous Escherichia coli. When corralled in the large intestine E. coli are great, but they are deadly when rampant in the rest of the body. Amazing.
I loved teaching students about how we use bacteria and other microbes make our food. Many dairy products rely on the fermentation of lactobacteria. Yogurt is the most obvious example, but other things such as cheese, cream cheese, sour cream, butter and butter milk are created by lactobacteria. One of my students was so disgusted by this that she swore to never eat cheese again.
Our bodies need lactobacteria to absorb nutrients from our food. They produce many B-vitamins and certain amino acids (needed to make proteins). Finally, lactobacteria help us eliminate waste effectively. For these reasons, yogurt is championed as health food.
Since teaching about lactobacteria, I have begun culturing my own in milk, otherwise known as making yogurt. From yogurt, I have advanced into preserving fruits and vegetables with lactobacteria. (This progression has been inspired by my sister-in-law’s experiments in laco-fermentation.)
Lacto-fermentation is not unlike what your skin does when it creates an environment conducive to the growth of good bacteria. I inhibit the growth of putrefying bacteria by adding heaping spoonfuls of salt. Lactobacteria, which normally grows on the skin of produce, is not affected by the salt. When competing microbes are removed, lactobacteria dominate, eating the sugars of the fruits and vegetables to produce various fermented food.
While not necessary, I add whey to the food I’m preserving. The whey is a clear fluid produced when yogurt or other cultured milk products are strained. Whey contains some of the lactobacteria from the yogurt, and gives the good bacteria a head start on growing in the food. As a bonus, a byproduct of straining yogurt for whey is cream cheese. Whey cool! (Sorry, couldn’t resist.)
After a few days of sitting on the counter, the vegetables or fruit will have a good culture of bacteria, the food will have been transformed. Then, the jar can be moved to the refrigerator prior to eager consumption.
Thus far, I have preserved lemons in salt and made two types of sauerkraut – one similar to the supermarket version (but without vinegar) and one with Latin American spices. The flavors are full and interesting, and the food keeps for months.
I’m looking forward to saving produce from my garden by this method later. Unlike traditional canning, it doesn’t involve standing over a large boiling pot of water for 20 minutes in an 90 degree kitchen.
I’m also attempting to capture and tame wild yeast but more on that later.