What’s The Difference? Fermentation vs Pickling
Fermentation and pickling can be easy to mix up; there are some areas of overlap that can easily spark some confusion.
After all, you can make fermented cucumber pickles, or pickled cucumber pickles. But, do fermented cucumber pickles qualify as fermented, or pickled? For the answers to this question and more, read on as we explore the overlap between these two methods of food preservation and preparation.
In short, here’s what you need to remember: Pickling involves soaking foods in an acidic liquid to achieve a sour flavor; and fermentation generates a sour flavor as a result of a chemical reaction between a food’s sugars and naturally present bacteria — no added acid required.
Pickled and Fermented, defined in detail
- Pickling - A pickled food has been preserved in a brine of equal parts acid and water mixed with salt. The brine can be salt or salty water, and the acid is often vinegar or an acidic juice like lemon juice. Pickled foods that are not fermented do not offer the probiotic and enzymatic benefits of fermented foods because they are usually heated for sterilization and preservation purposes during canning. However, when heated and canned, pickled foods can be stored at room temperature much longer than fermented food..
- Fermenting - A fermented food has been preserved by bacteria. One of the most common kinds of bacteria is Lactobacillus, a bacteria that eats the natural sugars and carbs and produces (among other things) lactic acid. This lactic acid preserves the food and adds to its flavor. Home fermented foods contain probiotics and enzymes that offer health and digestion benefits. These foods should be refrigerated or kept in a cool place like a root cellar.
Overlap between the two
While some pickles are fermented and some fermented food is pickled, not all pickles are fermented and not all fermented foods are pickled. It sounds confusing, but becomes clearer when we consider some examples.
- Fermented, not pickled - Yogurt, sourdough bread, beer, kefir, cheese, kombucha, and sour cream are all fermented foods that are not pickled. They are not preserved in an acidic medium, and the fermentation process does not generate enough acid to qualify them as pickled. These are mostly easy examples, as you wouldn’t look at a loaf of sourdough bread and think that it had been pickled. But, if you’re not familiar with kombucha, a fermented tea, you might wonder. It’s a liquid, but not salty, and it can develop a vinegar taste if left to ferment for an extended period of time. The answer? It’s a fermented food. The vinegar taste is created by bacteria in the SCOBY eating the sugars in the tea. On a side note, this 2 Gallon Keg and Spigot is great for fermenting and continuous brewing of kombucha teas. Visit our website for more information on all things kombucha.
- Pickled, not fermented - Store-bought pickles or anything that’s been quick-pickled is not a fermented food. These are a little harder than the last category to identify, but they do lack the distinctive flavor of a fermented food. If this is something you’re interested in, our ultimate canning kit for pickling and canning non-fermented foods has you covered.
- Both - Some foods are both pickled and fermented. Foods like sauerkraut, fermented pickles, and kimchi fall into this category. Surströmming, or Swedish sour herring, is both pickled and then fermented. In each of these foods, they are placed in a salty brine that kills off harmful bacteria, thereby pickling the food. The benign bacteria then goes to work fermenting the food, resulting in a fermented and pickled food. If you’re interested in fermenting your own food, this fermenting kit has everything you need to get started.
Notable Differences between Fermenting and Pickling
We’ll start with fermented foods. All fermented foods depend on bacteria to change their state, improve their flavor, and preserve them for later consumption. These bacteria thrive at certain temperatures, and depending on whether you’re using a mesophilic or thermophilic cultures, can die off if they get too hot. Mesophilic bacteria thrive between 68℉ and 113℉ and thermophilic bacteria thrive between 106℉ and 252℉. That’s why this electric yogurt maker is so helpful during the yogurt-making process. It keeps the milk at a constant preset temperature during the fermentation process. Some fermented foods, (like sourdough bread during the baking process,) use heat as part of the recipe to kill the bacteria. But in other fermented foods like kimchi, sauerkraut, or even fermented pickles, the bacteria and enzymes live on, only going dormant when the food is chilled or refrigerated. In fact, these foods must be stored below 45℉ and preferably refrigerated.
Pickled foods are much less temperature sensitive. They are often canned, which means they are heated to boiling and kept there for a set amount of time. This process would kill a mesophilic bacteria, but it also means these pickled foods are shelf-stable at room temperature.
Why choose pickling over fermenting or vice versa? Pickling creates food that can be stored for longer periods of time at room temperature. Fermenting can create a wider variety of foods, with more health benefits that contain like enzymes and probiotics, but most will require refrigeration and last for six months to a year at most, although some things like kombucha never expire. For more information about homemade fermentation, try Homemade Fermentation by Mortier Pilon, and for more pickling ideas, try our Favorite Pickles and Relish Book.