Fresh kraut after two weeks of cool-temperature fermentation. Photo by Shannon Stonger.

By Shannon Stonger
Health Impact News

Making fermented vegetables is both a science and an art. Understanding the biological processes behind vegetable fermentation can take you a long way in making simple, delicious batches of kraut. But it is the practice of making them again and again that teaches us what goes into the best batches of these living foods.

It is true; each batch of sauerkraut is a little different than the last. The condition under which it is made greatly affects the end result, but so does the vegetable itself and its origin. Microbes from the soil make their way onto a head of cabbage and then into your final product. In order to make the most of this process, it is helpful to understand how to manipulate the process to create the best kraut.

The Right Amount of Salt

One of the very first things I did when I first started fermenting was to follow guidelines that call for a great deal of salt. The kraut was edible but it mostly tasted like salty cabbage. I spoke with a Ukrainian woman about ferments one time who had grown up on kraut and kvass.

In relaying my salty kraut frustrations she said “just use less salt”. At the time I thought that salt was the major factor contributing to the preservation of the cabbage. I was wrong, to say the least, and when I cut down on the salt, the kraut turned into the most deliciously tangy, crunchy kraut I’d ever had.

Salt is good for you and avoiding it in your vegetable ferments is not only unnecessary but can create a less than desirable kraut. Salt helps the vegetable fibers hold up through the fermentation process, creating a crunchier product. Salt helps preserve the cabbage from unwanted microbes while the fermentation process goes to work on the ultimate preservation element in kraut – acids.

Salt also slows fermentation down, which means it needs to be in balance with the temperature at which you are fermenting. If you are fermenting in the heat of summer, adding a bit more salt to a ferment is not a bad idea. If you are going to be fermenting in cooler temperatures, less is needed.

A range of 1-3 tablespoons per full quart is a good rule of thumb to have in the back of your mind, though generally 3 is a bit high and vegetable ferments do not generally favor the temperatures that would necessitate such an amount.

A Good Fermentation Temperature

The only problem now is going through the kraut too fast. Photo by Shannon Stonger.

Heat speeds up fermentation, whether it is kraut or kombucha you are making. Wanting your ferments to finish up quickly is understandable, but there is often a loss of flavor and texture that go along with it. Instead of being in a rush, it is helpful to think of fermentation as a marathon, not a sprint. In that time you are waiting many good things are happening.

For one, fermenting at too high of a temperature can cause the structure of the vegetable to break down. This can result in mushy or slimy kraut, both of which are fairly unpleasant.

Secondly, flavor is impacted by the bacteria involved. When fermentation starts, certain bacteria are present. As it progresses other bacteria become involved. Most of these prefer a mild range of temperatures in order to proliferate. If temperatures outside of this range are present, the bacteria, and therefore the flavor, are affected.

A good rule of thumb is to begin at a room temperature of 65-80 degrees. After a few days at this temperature, moving it to a cooler (but not cold) environment is helpful. This could be a basement or root cellar in the 50-65 degree range. After at least a couple of weeks – and maybe even a few months – at this temperature, fermented vegetables will have a wonderful depth of flavor that cannot be had with a quick, warm fermentation.

Try It Sans Starter Culture

Using a culture is a bit like adding insurance to your fermentation. It ensures that you are starting off with the presence of beneficial organisms. This might be called culturing vegetables, which is a bit different than wild fermentation.

Wild fermentation of vegetables relies on bacteria present in or on the vegetables, coupled with the preserving qualities of salt. It is this vegetable-specific bacteria that creates a ferment that is unique to that vegetable.

The starter culture may give you peace of mind as you get started down the road of vegetable fermentation. But once you are comfortable with the process of allowing your vegetables to ferment for days, weeks, or even months without refrigeration; give wild fermentation a try and see if you notice a difference.