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The Fermentation Equation

Caterers are getting funky in the kitchen as they transform their menus with the help of fermentation

In recent years, the culinary world has witnessed a renaissance in traditional food preparation methods, and one technique that has emerged as a star player is fermentation.

Fermentation, an age-old culinary practice, involves the transformation of food through the action of microorganisms like bacteria, yeast, and molds. Although fermented foods have remained important parts of modern diets around the world, within the United States, they haven’t quite solidified themselves on menus yet. 

“Fermentation is nothing new; it has been occurring since before man walked the earth,” says Chef Alfred Francese (Emmer & Rye). “Trends come and go but we are not creating something unnatural. The most common bacteria found in fermented products are already present in our environment and on our food before we even harvest it.”

Pro tip: Make sure you use fresh vegetables without wax or other coatings.

Sure, several fermented foods—pickles, olives, vinegar, yogurt, sour cream, sauerkraut—have long been standard American fare. But whether most consumers realize these items are fermented or know what fermentation means is debatable.

“[Global diners] have been eating fermented foods every day forever,” says Keith Lord (Stratejē Fourteen), “but [Americans] don’t have a staple that we eat every day.”

Times have changed. In recent years, there has been an explosion of awareness, interest, and demand for fermented foods and beverages—and not just for familiar favorites. These days, consumers are clamoring for kimchi, kefir, and natto. They’re testing out tempeh, miso, and koji.  

The market for fermented ingredients is expected to expand at a value based CAGR of 6% and show an increase in revenue from $10.2 billion to around $18.4 billion by 2033. 

But why has fermentation suddenly become the darling of the culinary community? Perhaps it has something to do with its triple threat of benefits: complex flavors, sustainability, and health. 

“You’re able to build a culture within your kitchen that allows the cooks to have the freedom to look at that product and be inventive or creative,” says Chef Greg Shapiro (Tastebuds Custom Catering). “We’re not just doing it for the end result or to fulfill a job, we’re doing it for the betterment of everything.”

The whey to wellness

You know what they say: you are what you eat, and as consumers are prioritizing nutrition as the center of a balanced life, fermentation is proving to be an excellent solution to many health and wellness goals. There is substantial and growing evidence supporting the idea of fermented products as health foods. 

Pro tip: Plan to ferment your vegetables for two to six weeks, depending on your palate. You should ferment for at least seven days to allow for enough lactic acid to build up and kill any bacteria, such as E. coli.

Fermented milk products like yogurt, for example, have been shown to reduce health risks associated with type 2 diabetes, osteoporosis, and decreased brain activity. Many fermented foods enhance the availability of nutrients, thus promoting gut health, and can even contribute to a more balanced and diverse microbiome. 

Korean braised beef brisket with housemade kimchi, pickled jalapeños, natural jus, and buttery leek risotto. Photo courtesy Toque Catering

In conjunction with a healthy diet, the live microbes in fermented foods are also thought to help regulate glucose and blood pressure, reducing the risk of cardiovascular disease.

“It’s healthy, it’s something that we need in our diets,” says Lord.

Other health benefits of consuming fermented foods include: 

  • Improved digestion and absorption
  • Rich in probiotics
  • Immune system support
  • Detoxification benefits
  • Positive effects on mental health
  • Reduced risk of chronic diseases
  • Great source of probiotic bacteria
  • Aid in weight management, reducing fat accumulation and high blood sugar levels
  • Fight fatigue as digestive enzymes amylase and protease break down carbohydrates and convert them into energy
  • Rich in vitamin B1, vitamin B2 and vitamin B6

“Fermented foods are full of bacteria and that is what keeps our guts healthy,” says Chef Paul Buchanan (Primal Alchemy). “I believe more people have become educated about the positive benefits of fermentation. Of course, we may like beer and wine, but fermentation of vegetables adds a whole new dimension to our American diet that has become rather bland and semi nutritional.”

Striking a sour note

Beyond the good-for-you perks of fermented foods and beverages, there is also the flavor aspect. The fermentation process introduces a depth of flavors and versatile textures that can transform ordinary dishes into extraordinary, craveable culinary experiences. Incorporating fermented elements like pickles, relishes, or fermented sauces can add a sour, tangy, umami-rich dimension to your dishes, creating a mouth-watering menu.

“The addition of a sour or sweet/sour fermented item to a dish can create a complexity and balance of flavor that has rarely been reached before,” says Buchanan. 

Simply put, according to Sandor Katz, James Beard-award winning author of The Art of Fermentation, fermented foods are “the flavorful space between fresh and rotten.”

From seasonings to rubs to marinades to sauces, from pickles to brines, salt and acid are needed in every recipe and fermented products can bring different levels of both. 

“Fermentation completely transforms something into a different product,” says Shapiro. “For example, I make a strawberry kosho (strawberries, chilis, and salt) and the strawberries become dynamic. It allows the essence of the strawberry to come through but not that sweetness that you’re so familiar with, it becomes this spicy condiment that has strawberry in it, which is almost confusing in a sense because it’s just not what you anticipate it to be.”

Starter Cultures

Almost all fermented vegetable recipes, including homemade sauerkraut and sour pickles, don’t need or derive much benefit from the addition of a starter culture, and most are traditionally prepared without a starter culture. Instead of adding a starter to your fermented foods, you simply salt them, pack them into fermentation crocks or jars with an airlocked lid, and allow their native bacteria the time to do their work, turning those fresh vegetables marvelously sour and preserving them for long-term storage.

Fermented foods that don’t need a starter

  • All fermented vegetable dishes including sauerkraut, sour pickles, sauerruben, kimchi
  • Preserved lemons and limes
  • Bonny clabber, also known as clabbered raw milk

Some fermented foods require a starter culture to either ensure that they’re safe to eat and drink, to ensure consistent results with regard to flavor and texture or both.

Fermented foods that need a starter

  • Kombucha and jun tea
  • Water kefir
  • Yogurt
  • Milk kefir
  • Sourdough bread

Fermented foods that benefit from a starter, but don’t require one

  • Condiments and pastes that are difficult to keep submerged under brine
  • High-sugar fruits

Starter cultures to try

  • Whey from straining yogurt, kefir, or clabbered raw milk (sweet whey, powdered whey, and whey from cheesemaking will not work)
  • Brine from fermented vegetables such as sauerkraut juice or sour pickle brine
  • Kombucha or jun tea
  • Water kefir
  • A good-quality probiotic supplement
  • Packaged commercial starter culture
  • Koji
  • Sourdough starter
  • Juice from fermented vegetables 

Information above courtesy the following sources: 

This transformation opens a world of possibilities for chefs who can take a single ingredient and use it in myriad ways. 

“Chefs find it very intriguing to do it that way because it allows them to have that essence of that different ingredient that just takes the dish to the next level,” says Shapiro. 

The ability to transform ordinary vegetables and other foods into something much more exciting is a great benefit to caterers since it gives them the chance to add more complex and unique dishes to their menus without the added cost of purchasing new ingredients. 

“We have to reuse a lot of these products in different dishes, so we need to be sure they’re not redundant on our menu—each thing has to be widely different and lively and delicious in its own right,” said Francese. “With fermentation we now have a broader spectrum of flavors to pull from. 

“Your palate expands. Vinegar is no longer red wine, white, and apple cider vinegar; and citrus is no longer just lemon and lime. You have this broad array of acids you can use now, and this broad array of umami flavors and all these things. It’s a switch that goes off in people’s brains when they start to reach for these products and use them in a way that is impactful for the menu.”

Waste not

So far, we’ve touched on fermentation’s health benefits and the impact it has on transforming flavors. Now let’s look at the final aspect of this three-legged stool: sustainability. 

First, fermentation is a great medium for reducing food waste—it lets us create new and exciting flavors out of things that are normally seen as scrap or waste. 

“We are constantly trying to create different flavors, celebrate the abundance of foods and reduce what is commonly wasted,” says Francese, “and our pantry gives us the ability to do that.” 

Pro tip: Avoid exposing your vegetables to any bacteria. Wash your hands, vegetables, knife, containers, plastic bags, etc., and dry everything thoroughly.

For instance, fish bones can become an umami-rich sauce by fermenting with koji, or imperfect cherries can be fermented into a demi-glace and served over duck. A little imagination can create a luxury experience that you can call your own.

“It is fantastic to have the knowledge of how to use fermentation and other food preservation techniques to utilize the harvest to its fullest,” says Buchanan. 

Even typically discarded foodstuff, such as spent grains, fruit peels, and other production leftovers, can be fermented and repurposed into new foods and beverages that are innovative, nutritious, and downright delicious; the cut-off tops of chili peppers can be fermented with honey to create a delicious drizzle for breads and cheeses, leftover Swiss chard and kale stems can be pickled and served on a charcuterie board, or fermented carrot peels can be part of a salad with walnuts, golden raisins, dates, and mint. Even leftover wine can get a new lease on life by being transformed into vinegar. 

“It’s this idea of what else can you do with all those bits and pieces,” says Lord. “In a catering kitchen scenario, that Sunday morning when all the weekend’s events are done, take a look at what you have leftover that you can get more out of.” 

Sourdough banana bread from Real Simple. Photo courtesy Getty Images

Beyond reducing food waste, fermentation also helps to extend the shelf life of peak produce long past its growing season, thus allowing you to put out-of-season produce on your menus. 

Pro tip: Keep at room temperature (65°-75°) and away from direct light. Avoid storing your fermenting vegetables in a metal container.

Think: fermented Luxardo-style cherries (with koji and bitters) served over butler-passed scallops, fermented Brussels sprouts served on a Caesar salad, or pickled red onions for use in tacos or on salads.

“This way you’re able to have a year-round menu item,” says Lord. “You’ve added so much complexity to it and made it so versatile and usable.”

Don’t find yourself in a pickle

While fermentation offers numerous culinary benefits, it’s crucial for caterers to implement strict safety protocols when conducting in-house fermentation to ensure the quality and safety of the final products. 

“Especially in a catering scenario, you are dealing with bacteria,” says Lord. “You can make a batch of kimchi that is quite explosive if you haven’t done your leg work and understand time and temperature accordingly; you don’t want to create a bomb, you don’t want to make something that’s a health risk.”

Some of the key safety considerations to be aware of include:

  • Sanitation: Maintain a clean and sanitized environment in all fermentation areas to prevent contamination by harmful bacteria. Regularly clean equipment, utensils, and surfaces used in the fermentation process.
  • Temperature control: Monitor and control fermentation temperatures to ensure optimal conditions for the growth of beneficial microorganisms while inhibiting the growth of harmful pathogens. Invest in temperature-controlled fermentation chambers or rooms to maintain consistency.
  • pH monitoring: Regularly monitor the pH levels of fermenting foods to ensure acidity levels are within safe ranges. Acidity inhibits the growth of harmful bacteria and pathogens, contributing to the safety and stability of fermented products. Foods that “appear” to be safe can still contain harmful pathogens. It is recommended to use a digital pH meter or pH test strips that can measure to at least one decimal point. Test strips are less accurate as the color of the food can alter the result and many test strips don’t test to the accuracy of at least one decimal point.
  • Hygience practices: Implement strict hygiene practices for personnel involved in the fermentation process. Require employees to wash their hands thoroughly and wear clean attire to minimize the risk of contamination.
  • Training and education: Provide comprehensive training to staff members involved in fermentation processes, emphasizing the importance of food safety protocols and proper handling techniques. Stay updated on industry best practices and regulatory requirements.

By adhering to these rigorous safety protocols, caterers can harness the culinary potential of fermentation while ensuring the quality and safety of their offerings.

“Make sure you have a plan in place because it’s really easy to follow at that point,” says Shapiro. 

Let’s get funky

The versatility of fermented ingredients opens a world of possibilities for creative culinary applications. From fermented beverages like kombucha-based cocktails to innovative ferment-infused desserts, catering menus can showcase the diversity and flexibility that fermentation brings to the table.

Consider such things as pastas or pastries made from sourdough, using koji to marinade chicken or on steak to mimic dry-aging, pour kefir over cereal instead of milk or add it to fruit smoothies, try swapping meat for tempeh, such as tempeh tacos or in an Asian stir-fry with veggies, or bring seemingly opposite flavors together in something like a kimchi barbecue sauce.  

“The difference between a lot of the fermented foods you’re working with is that they have a number of different components within the fermented ingredient,” says Shapiro. “It’s a balancing act in the sense that you’re not just squeezing lemon on something where you’re looking to get acid and a little citrus flavor; now you’re taking something like preserved lemon and utilizing it in a whole different fashion. You’re getting a large amount of the essence of the lemon and the oils, but you’re also getting a lot more salt out of that now too. 

“You have to take into consideration all the different elements within that singular ingredient; it’s understanding the ingredient and what you’re producing at the end in order to really know where you’re going to implement it in the end.”

 Sinigang Chicken Wings featuring pickled green chiles. Photo courtesy McCormick for Chefs

There are other benefits of fermented products, too: they can help bind, thicken, and emulsify products, and they can aid in caramelization and Maillard reaction when applying heat. Fermented food products can also create unique textures uncommon to their native cuisine.

You can also capitalize on the interactive and engaging nature of fermentation by incorporating live fermentation stations into your catering events. Allow guests to witness the magic of fermentation firsthand, fostering a connection between the culinary process and the dining experience.

Food science

The process of fermentation can be as simple or as elaborate as the chef desires it to be. Some types of fermentation require specialized equipment, and a good deal of know-how, but you can ferment many vegetables with nothing more than salt, water, and a little bit of time. This makes fermentation a very easy and approachable method of processing ingredients.

“You can really go as rudimentary as just salting and curing,” says Shapiro. 

Examples of Fermented Foods

Fermented Vegetables

Lactic acid bacterial or lacto-based crock ferments of vegetables, for e.g., cucumbers or pickles are reviewed, then contrasted with vinegar-based preservation. 

Sauerkraut 

Sauerkraut is fermented cabbage. Although the name sauerkraut is German for “sour cabbage,” it’s believed to have come from China almost 2,000 years ago. A little salty and a touch sour, this crunchy condiment may be a good option for people who are new to fermented foods. You can eat it on sandwiches, with meat, or on its own.

Kimchi 

Kimchi is a fermented vegetable mixture of spices and vegetables like cabbage, radishes, leeks, cucumbers, or sweet potatoes. Originating in Korea almost 1,000 years ago, this traditional Korean food is now popular across East Asia and all over the world. Although typically a salty and sour mixture, kimchi comes in a variety of flavors depending on the spices, seasonings, and vegetables used. Some kimchi can also include meat, such as beef, pork, or seafood. Kimchi is often a side dish, but you can also mix it into other dishes, like dumplings, stew, or rice.

Dosa and Idli

A traditional South and West Indian dish made of fermented cereals, rice, and black gram that are ground, then fermented with salt, wild yeast, and lactic acid bacteria. The dough is fried (dosa) or steamed (idli).  

Fesikh

A traditional Egyptian fish dish that is dried before salting and goes through wild lactic acid bacteria fermentation.

Yogurt

Yogurt is made of pasteurized milk that is cultured with commercial lactic acid bacteria. The slightly sour taste allows yogurt to be used in a variety of ways, including as a marinade, in sauces or smoothies, or on its own. There are different types of yogurt available, but those with no added sugar are best. Add fruit, herbs, rolled oats, or a small drizzle of honey for added flavor.  

Cheeses

Today, most cheeses undergo fermentation. Aged cheddar, parmesan, Swiss cheeses, and some cottage cheese contain probiotics. Plant-based cheese is a fermentation of ground nuts (e.g. cashews) or nut liquids (e.g., coconut milk) made with commercial lactic acid bacteria and added flavor ingredients.

Natto 

Nato is a traditional Japanese fermentation of boiled soybeans with commercial Bacillus subtilis culture that makes the soybeans sticky and savory.

Koji

Koji fermented foods include traditional Asian foods such as miso, soy sauce, and a sweet beverage called amazake made with rice and cereals, such as wheat or barley. Koji foods are fermented with commercial Aspergillus oryzae molds creating enzymes that break down carbohydrates into sweet (amazake) and savory (miso, soy sauce) flavors.

Tempeh

A traditional Indonesian soybean cake made from fermented soybeans that have been pressed into a compact cake. This high protein meat substitute is firm but chewy and can be baked, steamed, or sautéed before being added to dishes. 

Kombucha and Jun 

Kombucha and jun are fermented beverages of Asian and Russian origin made of black tea and sugar (kombucha) or green tea and honey (jun). Symbiotic cultures of bacteria and yeasts (i.e., SCOBYs) are reused to create these carbonated, vinegar-based flavored drinks.

Water and Milk Kefir

Fermented beverages of Russian origin created with milk or water, sugar, and tiny grains called kefir containing lactic acid bacteria, acetic-acid bacteria, and yeasts, called a combined fermentation. You can drink kefir on its own or use it in place of buttermilk, milk, or water in dishes for a nice sour flavor. Thick kefir is similar in consistency to yogurt. You can eat it in the same way, for example, as a breakfast or dessert. This tart, lightly carbonated drink is made by adding kefir grains to room temperature milk and allowing it to ferment for 10–24 hours.

Fermented Sausages

Charcuterie meats may be made from beef, pork, or poultry and are fermented with commercial lactic acid bacteria, nitrites, salt and other ingredients. Molds often grow on the surface during ripening. These ready-to-eat sausages may be smoked hot (cooked) or cold (uncooked), and then dried. Examples include dry sausages such as pepperoni and semi-dry products such as summer sausage and cervelat salami.

Bonito Flakes or Katsuobushi

Dried, fermented, and smoked skipjack tuna that is shaved into thin flakes. They are commonly used to provide umami flavor to dashi stock, soups, stews, and sauces. They can be found in the Asian aisle of some supermarkets, in Asian groceries or online specialty stores. 

Miso

Miso is thought to have originated in China before making its way over to Japan some time during the 7th Century. It’s made by mixing soybeans, fermented rice, and salt before allowing it to ferment for several months. Miso has a rich, savory flavor and can be used in soups, sauces, and salad dressings, among other dishes.

Sourdough Bread

Sourdough bread is thought to have originated in ancient Egypt. The sourdough starter is made by fermenting a mixture of flour, water, and salt. A portion of this starter is then mixed with more flour and water to leaven the bread dough.While sourdough starters do contain probiotics, they are killed by the heat in the baking process. However, the baked bread does contain prebiotics. Similar to other fermented foods, sourdough bread has a slightly sour and salty flavor and is a delicious way to add a little tang anywhere bread is featured. 

Apple Cider Vinegar

The first record of vinegar dates back almost 7,000 years ago when the Babylonians used it for food preservation. In ancient Greece, Hippocrates used to prescribe apple cider vinegar for many ailments, like the common cold. Apple cider vinegar is made by adding yeast to apple juice and allowing it to ferment. It can be used in salad dressing, baking, pickling, soups, or any other dish needing a little tartness.

Information on this spread courtesy of the following sources:

If you’re interested in getting started 

with fermentation in your own kitchens, simple lacto-fermentation might be the best place to start. With this technique, essentially all you need is your produce, a tightly sealed vessel (such as vacuum seal bags or mason jars), salt, a room-temperature storage area, and time. 

“Quick pickling, regardless of the medium or flavors,” says Lord, “is an amazing way for me to ferment things that are conducive to the way I like to cook. Plus, you can line your tasting room shelves with your jars too and it’s super cool.” 

But before you get started with fermentation in the kitchen, do some due diligence to educate yourself; read some books, take classes, and taste test different products to fully understand the world of fermentation, since it’s a complex one.  

Pro tip: In dry lacto-fermentation, calculate 2% salt. With wet lacto-fermentation (which has the addition of water) the salt ratio rises to 3%.

“It’s a different part of what we do,” says Lord. “It’s completely different than cutting an onion and sautéing which everyone knows how to do, but maybe cutting it and lacto-fermenting is even a sentence that people don’t understand. You are dealing with other elements, not just heat.” 

After tasting your way through pickles and ferments, start experimenting with combinations of adding some fermented items to your favorite dishes to see how they work with the flavors. Once you have played with the fermented foods, you can better understand the products you would like to make yourself.

“Once you have a grasp on the science of it, everything can be fermented,” says Shapiro. “It’s like a toy box, it opens up everything for you.” 

With a little effort and advance planning, you can completely change the impact your ingredients have on a plate. By embracing the fermentation frontier, you can watch your catering offerings reach new heights of culinary excellence.

“You can create a pantry of delicious items,” says Francese. “The expected flavors are often not what result from the input of fermentation. Having a selection of items to use will help you stay creative and innovative.” 

Amber Kispert

Senior Content Producer

Amber is the Senior Content Producer for Catersource. Amber previously worked as a Communications Specialist for LeClair Group and a reporter for the Woodbury Bulletin, both located in Woodbury, Minn.  As a self-described "foodie," Amber loves to experience the world of food and beverages, and is excited to help share the stories of Catersource and the world's caterers.