With the rise of kimchi, kombucha, DIY fermentation, homemade pickles, and everything probiotic, you may have wondered: What is the difference between pickling and fermenting? They do share similarities, but microbes, time, and taste are some of the key differences between pickled and fermented foods.
One of my favorite memories of my niece as a toddler is of her jamming her teeny fingers into a jar of Rick’s Picks Smokra, lifting a piece to her mouth, tasting it with the tip of her tongue, and quickly putting it down with a look of surprise and dismay. She then waddled away, came back a moment later, and did it again—same move, same reaction. It might have gone on like this until the whole jar was empty if we hadn’t finally moved it out of her reach, crying with laughter.
That sour tang, which offended my niece’s delicate kiddie palate years ago, is something I often crave. Crunchy, salty, spicy, smoky, or sweet, I’ll take a pickle over any condiment, and can even make a meal of it (I’ve eaten an entire jar of pickled beets or kimchi for dinner on more than one occasion).
But until I started making my own, I didn’t fully comprehend how pickled and fermented foods differed; the two are often confused. So, we went straight to the experts to learn the difference between pickling and fermenting.
With or without Microbes
The first thing you need to know is that, while some fermented foods can be considered pickles (take these fermented dill pickles, for instance), not all pickles are created through fermentation.
“Pickling often refers to a quick [preservation] process using sugar, aromatics, and vinegar,” explains Michael Makuch, Associate Professor and Director of the Ecolab Center for Culinary Science at Johnson & Wales University. Fermentation, however, is an anaerobic process that occurs naturally when microbes break down sugars in food, resulting in the production of lactic acid. “There’s a lot of confusion,” Makuch concedes. “Fermented foods may end up pickled, but pickles aren’t necessarily fermented. As soon as you heat-treat a pickle, you kill the microbes.” And without those industrious little organisms, fermentation won’t occur.
”To pickle is to preserve with acid,” says Linda Ziedrich, author of “The Joy of Pickling: 300 Flavor-Packed Recipes for All Kinds of Produce from Garden or Market.” “The acid usually comes from vinegar as acetic acid or from lactic-acid fermentation. So, fermented vegetables are pickles. But fermentation can involve various organisms and acids. Bread, beer, wine, soy sauce, miso, tempeh, yogurt, cheese, and kefir are all fermented foods, but we don’t call them pickles.”
Sandor Katz, author of “The Art of Fermentation: An In-Depth Exploration of Essential Concepts and Processes from Around the World,” agrees. “I would define a pickle as anything that is preserved in an acidic medium, whether it be a cucumber, a hard boiled egg, pig’s feet, or beets. Virtually anything can be preserved this way. Most of what you find on supermarket shelves in 2019 are vinegar pickles, and have had a hot solution poured over them.”
People have been fermenting food for thousands of years, but vinegar pickles really only became popular when distilled white vinegar became commercially widespread in the mid-20th century, says Katz. “It’s generally assumed alcohol is the oldest form of fermentation,” he explains. He uses fruit ripened past its prime as an example, because its sugars have spontaneously fermented into alcohol. “Insects, birds, and animals, including primates, are drawn to the smell and flavor. The phenomenon is natural, and part of our deep evolutionary past.”
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We Want the Funk
In addition to whether or not bacteria play a role in the process, there are important differences between pickling and fermentation. Flavor is perhaps the most important. “Pickling gives you top notes from the brine, but not the complexity you get from fermented food products,” says Makuch. “Microbes provide complex flavor compounds. There’s a signature sour note you get in yogurt, or sourdough bread, and you may also get a bit of an earthy note, like in kimchi, which has an earthy funk in back notes. It can turn some people off if they’re not used to it. Or they may start to crave it, depending on their flavor palate.”
Texture & Time
Ziedrich points out that texture is also key. Take cucumber pickles, which you can make either by pickling or fermenting. “If you let the fermentation run its full course for two weeks or longer,” she says, “the cucumbers will soften somewhat. Although many people prefer ‘full sour’ pickles, others like their vegetables only partially fermented and still crisp.”
Most cucumber pickles you find on grocery store shelves have either been heated before being put in the jar or packed cold and then heat-processed. “Heat softens cucumbers, peppers, and some other vegetables, too,” Ziedrick warns. “To keep cucumber pickles from softening too much, you can use the low-temperature method of pasteurization: keep the jars immersed in a bath of water heated to 180 to 185 degrees Fahrenheit for 30 minutes. Better still, don’t heat the jars at all and store them in the refrigerator instead.”
If time is of the essence, then pickling is the best way to go. “You can make a quick pickle in 30 seconds with a chamber vacuum sealer,” says Makuch. Even without the fancy equipment, you can easily whip up a batch of quick refrigerator pickles in just hours. By contrast, fermentation can take days, even weeks, to yield desired results, and you have to babysit it to ensure the food is submerged beneath the brine to prevent spoilage.
Related Reading: Creative Ways to Use Leftover Pickle Brine
If you’re buying pre-packaged foods, you’ll also notice a difference in price and convenience. “If you pre-package [fermented food],” explains Katz, “it’s alive and producing pressure and must be refrigerated. By definition, it’s less shelf stable and more expensive.” However, he explains, in addition to having a superior flavor, fermented foods have much more to offer us nutritionally. Vegetables are an important source of vitamin C, but heat-processing diminishes nutrients. Fermented foods are also chock-full of probiotics, those good bacteria that help diversify the flora in our gut, which can potentially improve digestion, immune function, and even mental health. “It’s a trade-off between nutritional quality and shelf stability and convenience,” Katz concludes.
Related Reading: A Diet Rich in Kimchi and Sauerkraut Could Help Fight COVID-19
If you’re deciding between pickling and fermenting, Makuch recommends thinking about your end goal. “I think they both have their place,” he says, “but pickling is more limited in what you’re able to achieve.” Ziedrich recommends experimenting with a few recipes to figure out what appeals to you. Beyond the ubiquitous cucumber pickle or sauerkraut, you can make anything from pickled onions or watermelon rind to fermented tomato salsa or brined cherries.
And if, like my niece and me, you can’t keep your hand out of the jar, you may just end up making a meal out of the mouthwatering results.
This story was originally published in 2019; it has been updated with additional links.
Header image by Chowhound