For many, consuming such foods regularly helps tremendously with digestion, as they contain probiotics that help the body break down what we eat and drink. In addition to being good for you, they can also add intense flavours to cooking, which is why Zavou is so enthusiastic about his experiments, which are carefully labelled in glass jars, and which he lets us sample.

Some of the results have made their way onto the Mandarin menu. For example, a Japanese Miyazaki beef tenderloin dish is garnished with fermented mustard that has a complex, rustic and natural taste.

Zavou squeezes from a squirt bottle a thick sauce that tastes like seaweed thanks to its saltiness. “It’s fermented scallop and clam that took three months to ferment,” he explains, adding it is in the restaurant’s langoustine dish to enhance its sea flavour.

Another experiment is a plastic box filled with black powder that could be mistaken for cookie crumbs or fine soil. It has a round, subtle sweetness but we can’t put our finger on what it is.

“It’s onions that have been cooked for a long time then turned into powder. Garlic is typically paired with lamb, but it’s good with beef, too,” Zavou says.

He is excited by what the fermentation experiments are producing, but is still figuring out what they can be used for and more importantly, how can they be made in sufficient amounts to use in the restaurants.

“Fermenting food is incredibly beneficial for the health of our digestive system,” she explains, adding she eats it regularly and rarely, if ever, gets ill. “Consuming fermented foods allows for healthy bacteria to flourish in our gut, which aids in strengthening your immune system.”

The menu at the vegetarian and vegan restaurant indicates if ingredients have been fermented, cultured or pickled, and it provides a glossary for diners to understand more about what they are eating at Grassroots Pantry.

One of their successful items made in-house is the kefir coconut yogurt, which is used in a variety of ways on the menu – including a dill sour cream dip served with popcorn “chicken”, and a tiramisu that mixes kefir yogurt with a macadamia-cashew blend to create a mascarpone taste and texture.

Grassroots Pantry also makes its own kimchi. Chan says cabbage is fermented for more than two weeks before being used in a pancake made of mung bean and brown rice paste.

“Its natural acidity is all due to the fermentation process and makes it a very appetising and nutritious dish to consume as an appetiser,” she says.

Chan is cautious about how much fermented food can be served to customers. “Some people who are not used to eating fermented foods actually cannot take it well. And some customers cannot stand the taste of kefir, which exists in our AM elixir juice. The funkiness is not for everyone.”

She suggests people who haven’t tried fermented food consult their doctor before doing so and limit their consumption of it in case they may have an allergic reaction.

Soy sauce is the most commonly used fermented ingredient in Chinese cooking. Lau says it was originally similar to fish sauce used 1,000 years ago. “These days soy sauce is made using a chemical process, not natural, to ensure [consistency of flavour] and so it can be made in big batches.”

Lau explains the traditional way of making soy sauce involves a two-step fermentation process: you steam the beans and leave them in a controlled temperature and humidity for four to five days. Then the beans are placed in jars to which water and salt are added. The jars are placed in the sun for a few months.

“This takes up a lot of space and time – up to six months – so producers speed it up by using chemicals, but then the flavour is bland and flat,” he says.

Other soy fermented products include black beans, fermented bean sauce and fermented tofu. Lau says producers of tofu products will usually make soy sauce, too, so that the beans aren’t wasted.

“A few years ago I went to a shop in Sham Shui Po that is now closed, but I saw how they made fermented bean paste. They cooked the fermented beans and while they were still hot, transferred them into a large wooden pot and stirred the beans to distribute them evenly. The insulation from the wooden pot helped keep them warm; a stainless steel one would have cooled the beans down too quickly.”

Salted fish is another favourite because it contains lots of umami. “Salted fish is good to eat with congee or rice,” Lau says. The fish are naturally dried in the sun and then salt is added to stop fermentation and also dry the fish out more. “This enhances the amino acids in the flesh to make it taste better.”

Lau recently took a trip to China’s Sichuan province to learn more about its cuisine. “They pickle almost everything. They grow so many vegetables like cabbage and mustard greens, because they have warm winters, that they use fermentation to retain the harvest.”

If you want to learn more about fermentation, Sandor Katz, author of Wild Fermentation, will be teaching a class at the Mandarin Oriental on January 13. For information, look on the website healthylivingasia.com