Natural Fermentation: Salt vs. Whey vs. Starter Cultures

Posted by in Blog | 0 comments

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? Can one be substituted for another? What if you are dairy-free but your recipe calls for using whey (a dairy-byproduct)? Is purchasing a starter culture really necessary?  Do you actually need to use them?


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. Which combination you chose is dependent on your particular project and any dietary limitations you may have.

The skins of fruits and vegetables will generally come complete with natural bacteria accumulated during the farming and transportation process. These bacteria, if allowed to grow, will ferment your fruits 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. Assisting ingredients such as salt can inhibit the growth of undesirable microorganisms while favoring the growth of desired strains of bacteria. The natural culturing process can 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 of assisting ingredients, particularly 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 or brine. 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. When using salt without a starter, you are allowing the natural bacteria that exist on the vegetables to do the fermenting.
A benefit of salt is that it hardens the pectins in the vegetables leaving them crunchy and enhancing the flavor. The more salt you use, the slower the fermentation process and the saltier the taste. It is easy to salt too much, so we recommend salting to taste unless you want a longer storage time. (Please note, excessive use of salt can halt the culturing process by killing virtually all the microorganisms.) Many people prefer to use more salt with some ferments such as pickles and sauerkraut and less with ferments like ketchup, mayonnaise, or fruit.
Preparations with less salt will ferment faster and you will be more likely to see some white film on the surface that you can simply scrape off. It is likely to be an accumulation of yeast bodies. If some gets into your batch of vegetables, it won’t hurt to eat it. Salt-free ferments are actually more biodiverse but can result in mushy vegetables. For a salt-free ferment you can substitute celery juice or seaweed, but they will not prevent the mushy texture.


Starter Cultures

Using  some form of bacterial starter can speed up the fermentation process. Below are various starters that you might like to try. Many people find  that the type of starter they use affects the flavor so try various  types to see which ones your taste buds prefer.

Whey. Whey infuses the vegetables with good bacteria but is dairy-based so not recommended for those who are dairy intolerant. Make sure the whey is properly strained and fresh-tasting as it will lend its flavor to the batch. You can add salt along with the whey for flavor and to keep the vegetables crunchy. Using whey without any salt will make the ferment go faster but the end product will have a mushy texture and be more susceptible to mold. You can make whey by straining yogurt, kefir, or buttermilk or by clabbering raw milk.

Kefir Grains. You can add milk or water kefir grains to your vegetable ferments. Just mix them into the vegetables. Once your vegetables are fermented you can eat the grains along with your ferment or fish them out. Once milk kefir grains or water kefir grains have been used in a vegetable ferment, they normally won’t work again in a milk or sugar-based beverage. It is recommended to use new grains for each batch of fermented vegetables. Salt in these ferments is optional, and will slow the process but enhance flavor and crunch while offering some protection from mold.

Dried Starter Cultures. Vegetable Starter Cultures are dried bacteria, packaged in foil envelopes, that you can mix into your ferment. You can store them in your freezer and use as you need. This is a very simple and easy way to speed up your fermentation process.
With a starter culture you’re adding a known set of bacteria. While it is not necessary to purchase a dried culture, this option does offer the most consistent results in terms of taste and bacteria contained in the finished product. Dried cultures are also compatible with salt for taste, crunch, and some mold protection.

Please note: vegetable starter cultures generally contain dairy as a carrier agent for the culture. In some brands (e.g., Caldwell), when used in the proportions indicated by the packet instructions, the amount of dairy in the finished vegetable ferment is so small as to be below trace amounts.

Juice from One Ferment to Another. After you have made a batch of fermented vegetables and before you eat that last bite, take a couple of tablespoons of the fermented vegetable juice and add to your new batch as a starter. Salt will still be necessary if you want additional mold protection and a crunchy texture.