July 2019 Issue
Fermented Foods: Pickled Vegetables
By Mindy Hermann, MBA, RDN
Today’s Dietitian
Vol. 21, No. 7, P. 14
Understand the process to better help clients enjoy—and even make—these tasty treats safely and healthfully.
The popularity of pickles can’t be denied. According to Statista, 236 million Americans consumed pickles in 2018 and consumption is projected to increase to 239 million in 2020.1 Mordor Intelligence projects annual growth of 3.2% from 2018 to 2023, driven in part by consumer interest in health and taste enhancement.2 Pickles are so on trend that the fast food chain Sonic Drive-In featured a limited-edition pickle juice slush in summer 2018, and the National Restaurant Association named pickles as a top trend in 2018. That trend continues in 2019 as a solution to food waste, with chefs pickling trimmings and unused fruit and vegetable parts and incorporating them into dishes and garnishes. The popularity of probiotics also has given pickles and other fermented foods a boost. Ball and Mason jars, essential pickling supplies that once were available primarily in the late summer and early fall for canning, now are easy to find year-round.
Though pickled vegetables are most common, a pickle technically can be any food—cucumber, other vegetables or fruit, egg, herring, or even pig’s feet—that has been acidified for purposes of preservation and flavor, according to Kirsten Shockey, author of several books on pickled foods.
The popularity of pickling has opened the door to a growing variety of vegetables and sometimes fruits in the pickle jar. California-based pickle maker Bradley Bennett, under his Pacific Pickle Works brand, offers items such as Jalabeaños (green beans pickled with jalapeños), Asparagusto (asparagus spears with spices), Unbeetables (beets), Carriots of Fire (spicy carrots), Pickles Under the Ginfluence (cucumbers brined with gin), and Brussizzle Sprouts (semisweet and tangy Brussels sprouts).
Brine vs Vinegar
Pickles fall into two major categories based on the pickling liquid used—brine or vinegar—with both involving acid and salt. “In brined pickles, salt positively tips the table for strains of salt-tolerant lactic acid bacteria that bring down the acidity of the pickling brine,” Shockey says. Vinegar pickles aren’t fermented by bacteria and derive their flavor and texture from vinegar, salt, and spices.
Exposing foods to an adequate amount of salt during brine pickling prevents the growth of undesired microorganisms while allowing lactofermentation microorganisms to thrive, creating an acidic environment that preserves the food being pickled.3 Brined pickles tend to be made from vegetables rather than fruit because the sugar content of fruit can foster the proliferation of spoilage microorganisms. Lactofermentation pickling requires fully submerging food in a 15% to 20% salt solution and maintaining an anaerobic environment for about three weeks. Naturally present lactic acid bacteria on the surface of the vegetable ferment the vegetable’s sugars and starches into lactic acid, acetic acid, and carbon dioxide. The predominant bacteria strain changes during different stages of the fermentation process. Covering the surface of the brine with a plate, plastic wrap, another type of water-resistant wrap that sits on the surface, or a specially designed lid can help discourage growth of spoilage bacteria and yeasts that grow aerobically and tolerate the brine’s saltiness. Brined pickles must be stored in the refrigerator to retard additional fermentation and growth of detrimental microorganisms.
Vinegar pickles, called fresh-pack pickles, can include foods other than vegetables. The food is placed in brine for several hours, drained, combined with vinegar and seasonings in jars, and pasteurized in a boiling water bath or by another process. Pasteurization kills spoilage bacteria while infusing the pickled food with flavor from the vinegar and spices. Because their pickling process calls for heat pasteurization, they’re shelf stable until opened.
Cucumbers, the best-known pickling vegetable, can be pickled using either brine or vinegar (see the accompanying table). Brined cucumbers sometimes are characterized as half or full sours. Half sours spend less time fermenting, so they maintain some of the crunch and “fresh” flavor of a raw cucumber. In contrast, full sours develop a softer texture and tangy flavor. Placing half sours in the refrigerator will help prolong their crunchy phase and slow their development into a full sour. Vinegar pickles can be sour or sweet.
Nutrient content is similar between brine and savory vinegar pickles. According to the USDA, a medium-size cucumber pickle weighing 65 g supplies 7 kcal, 0.8 g fiber, and 30 mcg vitamin K, along with 785 mg sodium.4 Sugar present in sweet pickles pushes calories up to 59, but sweet pickles tend to be lower in sodium than savory pickles.
Advice for Pickle-Loving Clients
Nutritionally, pickles stand out for their sodium content, making them a food to limit for clients who have to restrict sodium intake. Some national and regional brands offer lower-sodium vinegar pickles (usually pickled cucumbers) as part of their product line; reduction in salt or substitution with nonsodium salts may result in flavor and texture that differ from conventional vinegar pickles. Salt can’t safely be reduced or substituted in classic fermented pickles because the high salt content helps retard growth of detrimental microbes.
For people who want to make pickles at home, the National Center for Home Food Preservation reinforces the importance of following recipe instructions exactly.5 This is particularly critical regarding the amount of salt in the recipe and the cooking time and temperature for vinegar pickles. Essential ingredients include canning or pickling salt and, if making vinegar pickles, white or apple cider vinegar with a stated acidity of 5% (ie, 50 grain).
Vegetables should be freshly picked and not have bruises, areas of spoilage, or wax or oil coatings. They must be washed in running water without any cleaning agents or antibacterial products that could kill off the lactic acid bacteria. Some recipes for pickled cucumbers recommend removing the blossom end of the cucumber because it contains enzymes that could cause softening.
Problems during pickling can be caused by several factors related to ingredients and process, including allowing air into the pickle solution, not using enough salt or vinegar, or brining pickles in a room that’s too warm.6 Undesired bacteria and yeast can cause pickles to become soft, develop a slippery surface, or show signs of mold. These pickles generally aren’t safe to eat. Shockey says, “When fermented pickles go bad, you usually know because they will smell bad or develop off colors and textures.” In contrast, pickles that are hollow, shriveled, dull in color, strongly flavored, or mildly effervescent, while less satisfying on a sensory level, are safe to eat.
Making homemade pickles requires close attention to food safety. In the late 1990s, new strains of pathogenic Salmonella and E coli were discovered that could survive in an acidic medium such as that used for pickling. In addition, Listeria monocytogenes has been shown to survive the fermentation process, particularly during room-temperature fermentation.7 This amplifies the importance of using clean equipment, refrigerating brined pickles below 50° F, and pasteurizing vinegar pickles at 180° F for the recommended amount of time to retard potentially harmful bacteria.
— Mindy Hermann, MBA, RDN, is a food and nutrition communications consultant in metro New York.
References
1. Statista. U.S. population: consumption of pickles from 2011 to 2020. https://www.statista.com/statistics/283153/us-households-consumption-of-pickles-trend/. Accessed May 1, 2019.
2. Pickles and pickle products market - growth, trends and forecasts (2019¬–2024). https://www.mordorintelligence.com/industry-reports/pickles-and-pickle-products-market. Mordor Intelligence website. Accessed May 2, 2019.
3. Desirable microbial growth in foods: pickle fermentation. Institute of Food Technologists website. http://www.ift.org/~/media/Knowledge%20Center/Learn%20Food%20Science/Microbiology
%20Experiments/TeacherGuidePickle.pdf. Accessed May 2, 2019.
4. US Department of Agriculture, Agricultural Research Service. USDA Food Composition Databases. https://ndb.nal.usda.gov/ndb/. Updated April 2018. Accessed May 7, 2019.
5. Preparing and canning fermented and pickled foods. National Center for Home Food Preservation website. https://nchfp.uga.edu/how/can_06/prep_foods.html. Accessed May 2, 2019.
6. For safety’s sake … pickle and pickle product problems. North Carolina State University, North Carolina A&T State University Cooperative Extension website. https://fbns.ncsu.edu//extension_program/documents/foodsafety_pickle_problems.pdf. Accessed May 2, 2019.
7. Kim JK, D’Sa EM, Harrison MA, Harrison JA, Andress EL. Listeria monocytogenes survival in refrigerator dill pickles. J Food Prot. 2005;68(11):2356-2361.