Why is salt used to ferment?
Salt has many functions in the fermentation process of vegetables.
First, salt pulls out water and some nutrients from the vegetables. By enveloping the vegetable(s) in this salty brine, the salt creates an anaerobic environment, i.e., an environment without air/oxygen, which is needed for the anaerobic, lactic-acid fermenting bacteria do do their work.
Second, the right amount of salt helps preserve the food. Salt inhibits the growth of spoilage and undesirable bacteria, yeasts, and molds while creating an ideal environment for the proper sequence of lactic-acid-creating bacteria, which feel at home at high salt concentrations. These lactic acid bacteria eat the carbohydrates in the vegetable, and create lactic acid, which lowers the pH of the solution, further helping to preserve the food from unwanted, higher-pH-loving bacteria.
Third, salt helps preserve the crispiness and flavor of the food. Salt does this by helping to delay the natural enzymatic activity in the plant tissue that breaks the tissue down and softens it.
Can I remove some of the saltiness?
If a naturally fermented food is too salty for your taste, you can remove some of the saltiness by rinsing the food under luke warm tap water. If it is still too salty, try soaking the food in luke warm water for about 15 minutes, stirring occasionally. Salt will be drawn out to the fresh water, until an equilibrium is reached. If still too salty, drain off the water, and add new water, repeating the process.
What type of salt do you use?
I use pickling salt. It is pure salt, i.e., sodium chloride (NaCl), without added iodine or anti-caking/anti-clumping chemicals, such as calcium silicate, that you would find in table salt. If you want to learn more about the gourmet salt craze (e.g., pink salt) and salt generally, check out the Info piece, Salt: Diet and Health Issues.
Salt photo. Salt quote from Kurlansky's salt, a world history
Is salt healthy or unhealthy?
Like many nutrition and diet questions, the answer is: "Depends." Below are the key points on sodium and health. (Check out the post, Salt: Diet and Health Issues, for detailed info on the below points.)
1.) Sodium, which makes up salt, is critical for cellular function, and our survival, but we only need a certain amount.
2.) The studies on the health affects of excess salt intake are not entirely clear. The one consensus is in regards to who definitely benefits from eating less salt: people who already suffer from hypertension. Reduced salt intake does not seem to benefit those without hypertension, and some studies claim to show that eating very little or no salt seems to have its own adverse health issues.
3.) The main problem with the sodium issue is that we get most of our sodium from consuming processed food, factory farmed meats injected with chemical solutions of sodium phosphate, and heavily salted restaurant food. These "Frankenfoods" have had many nutrients and fiber removed, and are very high in added salt, sugar, and fat.
4.) We can greatly and healthily reduce sodium intake by eating more whole or minimally processed foods, and preparing real food at home. By doing so, we can judiciously use the salt shaker, and eat naturally-fermented foods without worrying about getting too much sodium.
5.) Eating real food--and more plants, specifically--gives us the added benefit of providing us with more potassium, which helps counteract damaging effects of sodium. (In addition, eating real foods provides us with many other nutrients and benefits that are lacking in processed foods. Indigestible carbs, e.g., fiber, is one such benefit in whole plant foods. Indigestible carbs are critical to our gut health, which means they are critical for our health. Read more here, in the post, Our Microbiota: Critical to Our Health.)