Chefs are using fermentation to infuse dishes with rich layers of flavor.

Fermentation continues to experience something of a renaissance in contemporary kitchens, with restaurants leveraging the age-old technique as a cost-effective way to give new life to food waste while adding complex flavors to the menu. 

Every dish at Chef Sean Brock’s flagship Audrey restaurant in Nashville features something from the fermentation lab, where research and development manager Elliot Silber combines his science background and culinary expertise to support the team’s “no such thing as waste” mentality. Much of that work centers around distilling the flavors of raw produce and transforming food scraps into fermented syrups, salts, and seasonings. 

Silber takes fruit and vegetable trim from the kitchen and lacto-ferments it with salt for around two weeks before running it through an apple cider press. Then, he concentrates the liquid in one of two ways. 

“The first method is to freeze it and then thaw it back out in a refrigerator,” he says. “All of the salty, all of the sour, and all of the sweet will melt off first. If you catch it at the right moment, you just lift up a pearly block of ice and all of the liquid underneath is 40 to 60 percent stronger. We use that technique to create these lacto-vinegars that have a really intense fruit or vegetable flavor.”

The second method is to add sugar to the liquid and slowly reduce the mixture in a dehydrator until it reaches a thick, honey-like consistency. The result is a lacto-syrup that packs a similarly powerful flavor punch. 

Along with Western-style pickling and lacto-fermentation, an entire side of the lab is devoted to koji-based concoctions inspired by East-Asian culinary traditions. That’s where Silber creates “every kind of allegory to soy sauce, miso, fish sauce, and oyster sauce” using the Southern and Appalchian ingredients that Chef Brock grew up with. 

The various syrups, salts, and seasonings coming out of the fermentation lab enable the chefs at Audrey to put fewer things on the plate with a bigger impact. 

“Imagine taking a squash and cooking it in its own juice. That’s squash times two,” Silber says. “You season it with this stuff that’s sweet, salty, and sour. That’s squash times five. If you have an umami sauce, like a soy sauce or garum made out of squash, that’s squash times six. We also make salts out of the brine from pickling things, so now you have squash times seven or eight in one dish. The guest is presented with a piece of squash that has this amazing complexity and depth of flavor to it … and that’s because we seasoned it with all of these ferments that were made out of the same ingredient.” 

Managing such a robust in-house fermentation program is no easy task. It requires constant collaboration and communication between the lab and the kitchen. Silber relies on an enormous spreadsheet with dates and reminders to keep track of all the moving parts. 

“Some things take two weeks, some things take two months, some things take six months, and some things take a year or more,” he says. “Sometimes, you’ll have something that needs to be stirred every week for the first two months, then left alone for eight months, then stirred every week or two after that. It’s definitely a lot of maintenance.”

Like many chefs, he credits NOMA with sparking the widespread resurgence of fermentation in today’s kitchens. The renowned Copenhagen, Denmark, restaurant famously housed 10 fermentation rooms at varying temperatures. That doesn’t mean chefs need to set up their own in-house lab or bring on a dedicated specialist to tap into the trend, though. Silber encourages chefs with a passion for sustainability or an interest in fermentation to start small and begin by looking at the food that’s already being wasted. 

That’s how Tim Payne, executive chef at Cowhorn Vineyard & Garden in Oregon’s Applegate Valley, got started on his fermentation journey. His role at the biodynamic winery allows him to oversee the entire culinary process, from planting and harvesting a variety of fruits and vegetables to preserving his own ingredients and planning all of the estate’s dining offerings. 

“Fermentation is a pretty simple process when you break it down,” Payne says. “It’s just salt and water and then letting the natural process take over. Understanding the correct ratio and observing proper sterilization and storage techniques—that’s where the devil is in the details and where people can go wrong.”

He started fermenting a couple of years ago, experimenting with green beans, summer squash, beets, strawberries, and other excess fruits and vegetables to showcase home-grown produce in the winery’s tasting menus and family-style dinners. Now, he’s taking the technique and bringing it to the menu at Cowhorn Kitchen & Wine, a spinoff restaurant that opened last month in Jacksonville, Oregon. 

The new restaurant utilizes fermentation in subtle and sometimes unexpected ways. Think french fries made with fermented potatoes, ketchup made with fermented tomatoes, and sauces made with fermented blackberries. 

“We’re incorporating it into salads as we get away from the growing season, so instead of having a fresh carrot, you’re getting a fermented carrot that provides a really nice flavor pop,” Payne says. “For us, it’s an extra component you can add to a dish rather than the focal point. We’re using what we’re growing and what our neighbors are growing, and since you always either underestimate or overestimate what you’re going to get in terms of harvest, fermentation is a great way to deal with overabundance.”

Feature, Menu Innovations