Long before canning, before vacuum-sealed packets of tuna, before pasteurization, refrigeration, and other industrial food processing techniques, people used the power of fermentation to preserve their foods. Holes were dug, crocks were filled, and harvests were packed into brine (salty water) for future use.
Fermenting of food dates back thousands of years and is common to most cultures around the world. From the familiar Korean kimchi and German sauerkraut to much rarer dishes such as Inuit Igunaq (fermented walrus meat) and African fufu (fermented cassava tubers), people around the world enjoy the health benefits and unique tastes of fermented vegetables, fruits, and meats.
Fermentation differs from other food preservation techniques such as canning and pasteurization in that with fermentation, you are harnessing beneficial bacteria to transform food into something that is less perishable and healthier than the original food. High-heat processes such as canning destroy all the living organisms in a food.
The bacteria that keeps food from spoiling quickly in summer heat also breaks down food in ways that makes it easier to digest. This is why people who are lactose intolerant and can’t drink milk, for example, may be able to eat the fermented version of milk—yogurt—because the bacteria has consumed the lactose during the fermentation process.
Fermented foods can be more nutritious as well, because fermentation preserves and sometimes increases enzymes that help our digestive system break down food more efficiently to better absorb the nutrients. Fermented foods can even increase the digestibility of the foods they are served with, which is why sauerkraut cozies up to pastrami on a Reuben sandwich and kimchi on your hotdog may fend off heartburn.
Considered live foods, fermented foods contain probiotics—important microorganisms that live in our intestinal tracts. These probiotics cannot withstand the heat of modern food processing techniques so they are often missing from our diets. The importance of maintaining healthy intestinal flora is beginning to be more widely recognized and eating fermented foods is a good way to ensure our guts are populated with enough beneficial bacteria such as Lactobacillus, the probiotic found in sauerkraut, yogurt, and miso.
How Fermentation Works: Just add Salt
In fermentation, salt acts as a preservative while microbes from the fruits and vegetables convert their starches and sugars into lactic acid, a process known as lacto-fermentation. Lactic acid is what creates the sour flavor of fermented foods. Naturally fermented foods can be found in the refrigerated section of health food stores because, unlike products pickled using high heat and vinegar, they are not shelf-stable. You'll likely pay more for these artisanal products, so it's a good thing that anyone with access to fresh veggies, oxygen, water, and salt can ferment their own. The process is simple and the results are delicious.
2 small green cabbages (about 5 pounds)
3 tablespoons sea salt
Extra sea salt (as needed)
Ceramic crock or glass jar large enough to hold shredded cabbage with a little room
A weight of some sort (see below)
Large mixing bowl
- Carefully core the cabbage, removing the hard center completely. Cut cabbage into quarters so it is easier to handle and slice into thin strips roughly 1/16” and 1/8” wide.
- In a large bowl, mix the salt into the cabbage, working with your hands to ensure thorough coverage.
- Pack the salted cabbage into your crock or jar, pressing down each handful and compacting the mix into the bottom of the container.
- You will notice that as you add salt and pack the container the cabbage begins to release liquid. This is the natural brine that will turn your humble cabbage into delicious kraut! This liquid will fill up the air spaces between the pieces of cabbage and start the fermentation process. Make sure to add any of the liquid left in the mixing bowl to the crock or jar you are packing the cabbage into.
- For sauerkraut to be successful, the cabbage mixture must always remain covered with brine. Often store-bought cabbages have less moisture than farm-fresh ones and need a little extra help. If the packed cabbage does not produce enough liquid to cover itself as you pack it in the container, just mix a heaping tablespoon of sea salt into a quart of water and add as needed to cover the cabbage.
- Finally we need to make a weight that will hold the cabbage under the brine while it ferments. Cooks with dedicated fermenting equipment often have a special wooden weight made to fit their crock, but we will use a simpler method.
- Double up two clean plastic grocery store vegetable bags and fill them with a quart of water mixed with a tablespoon of sea salt. Tie the bag tightly and place on top of the cabbage mix. The weight of the brine bag will keep the cabbage submerged in the liquid.
- Put your crock or jar in an out-of-the-way place out of direct sunlight. Give it a week or so to do its thing. Spoon off any of the foam that floats on the top. This is a harmless byproduct of the fermentation process.
- Taste your sauerkraut after eight days. The time needed to ferment varies widely and personal taste will determine when it’s ready. It’s safe to eat at all stages of fermentation. When desired sourness is reached, remove the weight, cap the jar or crock, and store in the refrigerator.
Kimchi is usually made with Napa cabbage as its base, and often includes other vegetables as well. The process is similar to making sauerkraut.
1 large Napa cabbage (about two pounds)
3 quarts cold water
½ cup sea salt
½ cup daikon radish, sliced into matchsticks
½ cup carrots, sliced into matchsticks
1 cup scallions, chopped
1 tablespoon garlic, minced
¼ cup fresh ginger, peeled and minced
1/4–1/3 cup Korean chili powder (find this at an Asian supermarket or substitute a mix of half ground cayenne pepper and half smoked paprika for a similar taste).
Large mixing bowl
Glass jar (One-gallon size. Big enough to hold all ingredients with a little room)
Rubber gloves (optional, but the chili powder is super hot!)
Brine bag or other weight (see above for brine bag instructions)
- Core and chop the cabbage and place in a large mixing bowl. Mix ½ cup salt with three quarts of water. Cover cabbage with salt water. Place a dinner plate on the cabbage to keep it submerged and allow it to soak for 6–8 hours.
- Drain cabbage and rinse thoroughly. The cabbage should be softened a bit from this brining.
- Return the cabbage to the mixing bowl and add the remaining ingredients. Wearing gloves, work the vegetables until the chili powder is evenly distributed and place the mixture into your glass jar. Remember to pack down the vegetables as you go. Cover the mixture with a brine bag weight and place the jar in a cool, dark place.
- Napa cabbage is a “wet” cabbage and should continue to create its own brine from its previous salt water bath even though it has been rinsed and mixed with the other ingredients. This might take a little time, so you can wait until the next day to check it and see if the cabbage has made enough liquid to cover itself. If not, mix a little extra brine (A heaping tablespoon of sea salt in a quart of water) and add a tiny bit to the mix.
- The kimchi should ferment from four days to a week in a dark place and should then be transferred to the refrigerator. It will keep up to a month but it will most certainly be eaten up long before that!
This basic kimchi is delicious as a condiment on hot dogs and other meats, or use it to spice up leftover rice to make incredible Korean fried rice.
Corinna Andrews is a writer and editor in Portland, Oregon.