Natural Fermentation: Salt vs. Whey vs. Starter Cultures
When making naturally cultured vegetables, fruits or condiments, recipes will often call for a variety of ingredients including salt, whey and salt, or even just a freeze-dried culture. How do you choose the best culturing medium for your project?
Purpose of Salt and Other Ingredients for Fermentation
Salt and starter cultures such as whey, kefir grains, and freeze-dried cultures can promote the fermenting process by inhibiting the growth of undesirable microorganisms, favoring the growth of desired Lactobacilli, and in some cases even adding desirable bacteria to the culturing process. The combination you chose is dependent on your particular project and any dietary limitations you may have.
The skins of fruits and vegetables contains natural bacteria. These bacteria, if allowed to grow, will ferment the fruit or vegetables. Unfortunately, not all bacteria are created equal, and some of the present bacteria as well as bacteria in the surrounding air may not lead to a tasty finished product. Salt inhibits the growth of undesirable microorganisms while favoring the growth of desired strains of bacteria. The natural culturing process may be further encouraged and sped up by adding beneficial bacteria through the use of whey, a starter culture, kefir grains, etc. While we do strongly encourage the use salt, to improve outcomes and avoid the growth of undesirable bacteria, the use of salt, whey, or freeze-dried cultures is not strictly necessary.
Historically, salt was used to preserve foods before refrigeration. Vegetables ferment better under the protection of salt dissolved in water. Salt pulls out the moisture in food, denying bacteria the aqueous solution they need to live and grow except for the desired salt-tolerant Lactobacilli strains. By suppressing the growth of other bacteria and mold, salt provides a slower fermentation process that is perfect for cultured vegetables that are to be stored for longer periods of time. We recommend salt ferments, to allow the natural bacteria that exist on the vegetables to do the fermenting.
Using some form of bacterial starter is said to speed up the vegetable fermentation process. While we recommend a salt-only ferment for vegetables, the following may be added in addition to salt, if desired.
Making Substitutions in Recipes
If you come across a recipe that calls for one type of starter culture, but you'd prefer to use another or leave them out altogether, here are some general guidelines: