Fermentation 101: A Beginner’s Guide to Fermenting Vegetables at Home

Fermentation 101: A Beginner’s Guide to Fermenting Vegetables at Home
As fermented foods metabolize their carbohydrates, they release beneficial nutrients such as B vitamins—making fermented foods often more nutritious than their fresh counterparts.(Sentelia/Shutterstock)
2/15/2023
Updated:
2/15/2023

In the old days, before you could hop in a car and head to the supermarket, winter meant hunger. Everything you needed to survive the cold, dark days of winter when fields lay fallow had to be harvested in the fall and preserved. There was no takeout, no frozen food section, no meal kits delivered to your door, and no fresh berries trucked from thousands of miles away. You had a hand in making everything you ate, and preserving the harvest was essential, lest bellies go empty during hard times. Before canning, one of the best ways to preserve food was to ferment it.

Fermentation is the deliberate process of introducing beneficial bacteria into food to convert its naturally occurring sugars into various acids. These acids preserve the food and make it taste pleasantly sour. Grapes become wine, and then vinegar. Milk transforms into yogurt or cheese, and cabbage turns into sauerkraut.

Health Benefits

Historically, preserving food was the impetus for fermentation; nowadays, you’ll find much more interest in its health benefits. As it turns out, not only does fermentation preserve food, but it also transforms it into a nutritional powerhouse. Fermented foods are rich in beneficial bacteria. Those microorganisms responsible for turning sweet milk into tangy yogurt or cucumbers into sour pickles are also good for the gut. Moreover, as they metabolize all the carbohydrates in fruits, vegetables, and milk, they also release beneficial nutrients, such as B vitamins. That means fermented foods are often more nutritious than their fresh counterparts.

It’s for this reason that researchers have described fermented foods as “functional foods.” The term functional food was coined in Japan during the early 1980s, and researchers use it to describe foods that convey greater benefits than nutritional value alone. Oats and their ability to support healthy cholesterol levels are one example. Another well-known functional food is cold-water fish, such as salmon, which is rich in omega-3 fatty acids. Research suggests that these healthy fats support heart health, reduce inflammation, and support cognitive function. More than basic nutrition, these foods convey greater benefits, such as reducing one’s risk of disease.

A 2022 paper published by Nutrients describes fermented foods as functional foods primarily because they’re associated with better gut health, which may have beneficial effects on other aspects of health, such as a reduced risk of cardiovascular disease and Type 2 diabetes.

Because of their benefits and long history of use, fermented foods are an important, if not essential, element of the human diet. Sadly, they’re largely lacking in the modern diet. Since fresh food and packaged, processed foods are so readily accessible, there’s little need to preserve foods as our ancestors did. Yet fermented foods are still worth making, and it’s a lot easier than you might expect.

Committed fermentation enthusiasts often use a fermentation crock, which has an airlocked lid perfect for your fermenting needs. (Karl Allgaeuer/Shutterstock)
Committed fermentation enthusiasts often use a fermentation crock, which has an airlocked lid perfect for your fermenting needs. (Karl Allgaeuer/Shutterstock)

How to Get Started

Fermented vegetables are among the easiest foods to make yourself, but it takes a little know-how and a lot of patience. Sauerkraut and pickles, because they’re simple and fairly well liked, are good projects for fermentation newcomers.

To get started, you’ll need vegetables, salt, and a container. A mason jar with a tight-fitting lid works fine, but committed fermentation enthusiasts typically graduate to dedicated crocks or jars fitted with airlocks or lids designed specifically for fermentation.

Salt is essential when fermenting vegetables because it helps give them flavor, keeps them crisp, and creates an environment that supports the growth of good bacteria. For most vegetables, you’ll use about 2 percent salt by weight, although peppers can benefit from a higher ratio (up to about 3.5 percent). For sauerkraut, as with similar shredded vegetable ferments, you’ll combine the salt with fresh cabbage in a bowl. The cabbage will release liquid, which combines with the salt to create a brine; it all goes into a sealed jar, and the good bacteria do their work. For sour pickles and similar brined vegetables, you’ll pack a jar with the vegetables and then cover them with a saltwater brine.

With time, beneficial bacteria will metabolize the carbohydrates in your vegetables, pickling them. It can take a few weeks for small batches and several months for large ones. For safety, always keep the vegetables completely submerged in the brine. Additionally, seal the jar tightly to prevent airflow, which encourages mold growth. Carbon dioxide builds up during fermentation, so using an airlock or fermentation seal is helpful, or you can open the jar briefly every day to allow the carbon dioxide buildup to escape.

After the recommended amount of time, taste your ferment, and when it tastes pleasantly sour, it’s ready for the fridge. Discard any jars that smell putrid rather than sour, have a viscous texture, or have visible signs of mold. Stick to these tips and well-established recipes, and have fun.

Making sauerkraut at home is marvelously easy, requiring only cabbage, salt, and a mason jar. (Sergii Gnatiuk/Shutterstock)
Making sauerkraut at home is marvelously easy, requiring only cabbage, salt, and a mason jar. (Sergii Gnatiuk/Shutterstock)

Sauerkraut

Sour and richly complex, sauerkraut is a vibrant fermented food with deep flavor. While making sauerkraut at home can seem complicated, it’s marvelously easy. And you only need two ingredients: cabbage and salt.

Makes about 1 quart

Ingredients
  • 2 pounds cabbage (from 1 head)
  • 4 teaspoons fine salt
Special Equipment
  • 1 quart-sized mason jar with lid
Remove any exterior leaves from your cabbage, reserving one, and then slice the cabbage in half crosswise. Remove the cabbage’s core, and then slice the cabbage into strips no wider than 1/8 inch.

Toss cabbage and salt together in a large mixing bowl and let rest for about 20 minutes, or until the cabbage begins to soften and release a little juice. Then squeeze the cabbage with your hands to soften it even further and help it to release more juice.

When the cabbage has become limp and has released ample juice, transfer it to your jar. Pack the sauerkraut tightly into your jar, using a kraut pounder or a wooden spoon, so that the cabbage continues to release its liquid and no air bubbles remain.

Continue packing the cabbage into the container until it is completely submerged in its liquid. Wedge the reserved cabbage leaf over the shredded cabbage so that all the vegetables remain completely submerged in brine. Seal the jar tightly, and set it in a small bowl to catch any overflowing juices. Burp the jar daily to release excess gas.

Allow the cabbage to ferment at room temperature and away from direct sunlight for at least two weeks or until sour enough for your liking. Transfer to the fridge, where it will keep for six months to a year.

Sauerruben, or fermented turnips, takes on a pleasant sour punch that’s brightened by the lightest touch of caraway. (DUSAN ZIDAR/Shutterstock)
Sauerruben, or fermented turnips, takes on a pleasant sour punch that’s brightened by the lightest touch of caraway. (DUSAN ZIDAR/Shutterstock)

Sauerruben

Turnips are delicious when fermented. They take on a pleasant sour punch that’s brightened by the lightest touch of caraway. Serve sauerruben on its own or over sausages.

Makes about 1 quart

Ingredients
  • 2 pounds turnips, trimmed of root tip and stems
  • 1 tablespoon caraway seeds
  • 4 teaspoons fine salt
Special Equipment
  • 1 quart-sized mason jar with lid
  • Glass fermentation weight (optional)
Finely grate the turnips using a food processor or box grater.

Toss turnips, caraway seeds, and salt together in a large mixing bowl and let rest for about 20 minutes or until the shredded turnips begin to release their juice. Then, squeeze the shredded turnips tightly with your hands to soften them even further and help them to release more juice.

Transfer the turnips to your jar when they become limp and juicy. Pack the turnips tightly into your jar, using a kraut pounder or a wooden spoon, so they continue releasing liquid and no air bubbles remain.

Continue packing the turnips into the container until completely submerged in their brine. Weigh down the turnips with a glass fermentation weight if available. Seal the jar tightly, and set it in a small bowl to catch any overflowing juices. Burp the jar daily to release excess gas.

Allow the turnips to ferment at room temperature and away from direct sunlight for at least two weeks or until sour enough for your liking. Transfer to the fridge, where it will keep for at least six months to a year.

Thyme and black pepper give these fermented carrots a pleasant herbal aroma, while a single jalapeño and plenty of garlic give it a kick. (Jennifer McGruther)
Thyme and black pepper give these fermented carrots a pleasant herbal aroma, while a single jalapeño and plenty of garlic give it a kick. (Jennifer McGruther)

Carrot Pickles

Thyme and black pepper give these fermented carrots a pleasant herbal aroma, while a single jalapeño and plenty of garlic give it a kick. Like most fermented vegetable recipes, this one is super simple to make.

Makes about 1 quart

Ingredients
  • 6 medium carrots
  • 1 jalapeño
  • 4 medium garlic cloves
  • 6 fresh thyme sprigs
  • 1 teaspoon black peppercorns
  • 2 cups room temperature water
  • 1 tablespoon fine salt
Equipment
  • 1 quart-sized mason jar with lid
  • Glass fermentation weight, optional
Slice the carrots into 1/4-inch-thick sticks, and then arrange them lengthwise into a quart-sized jar. Next, slice the jalapeño in half lengthwise and arrange it with the carrots. Drop in the garlic cloves, thyme, and black peppercorns.

Whisk the salt into the water, then pour it over the vegetables.

Place a glass weight over the vegetables so that they remain submerged under brine, and seal the jar tightly. Allow the carrots to ferment for about two weeks, burp the jar daily, then transfer them to the refrigerator, where they'll keep for up to six months.

Jennifer McGruther, NTP, is a nutritional therapy practitioner, herbalist, and the author of three cookbooks, including “Vibrant Botanicals.” She’s also the creator of NourishedKitchen.com, a website that celebrates traditional foodways, herbal remedies, and fermentation. She teaches workshops on natural foods and herbalism, and currently lives in the Pacific Northwest.
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