TMS Features —

Extreme Fermentation

While there is an extensive science behind fermentation, the basic idea revolves around the process in which yeast or bacteria interacts with sugars and starches that are naturally occurring in food products.

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Fermentation has been around for many millennia, with its origins in the natural fermentation beer in Israel over 15,000 years ago – but only in the past 150 years has it really been extensively studied and connecting yeast and sugars to the fermentation process. While there is an extensive science behind fermentation, the basic idea revolves around the process in which yeast or bacteria interacts with sugars and starches that are naturally occurring in food products. The byproducts of this include alcohol, various acids and probiotic bacteria – all of which add to the distinctive character of fermented food and drink products. Aside from increasing the longevity of the product and seasonal sustenance for remote communities, numerous research has pointed out the health benefits associated with fermentation in general, although similar studies have also shown the potential dangers in the process of fermentation and possible health risks also.

Even though fermented products have been part of many diets for a long time, the result is an ever-increasing move towards understanding fermented foods more and more. “Superfood” labels have been attached to such products as kombucha, kimchi, miso, lassi and natto and entire schools of thought have been devoted to creating balanced diets and healthier living. To the degree that an increasing number of restaurants have included fermentation as a significant part of their menus.

While, we will not go into the science behind fermentation nor food microbiology, this is a brief exploration of the more extreme fermented foods, as well as some of the more progressive restaurants and chefs that have been utilized fermentation in modern cuisine. We have also omitted some of the more ‘commonly’ found fermentations such as sauerkraut, kimchi, kombucha, shiokara, milks, salami and even shrimp for this coverage to focus more on the unique and extreme fermentables.

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Vegetables are one of the most common things to ferment, so we will only look at this group briefly. With the most obvious starting point being cabbage, given the increasingly high consumption of both sauerkraut and kimchi around the world. The natural lactic acid bacteria inside the vegetables, particularly cabbage is a key driver for the 3 weeks it takes for kimchi fermentation to complete (compared to 6 weeks for sauerkraut). The addition of seasoning such as garlic, red pepper and fish sauce combined with the lower temperature fermentation distinguishes kimchi to its cousin which starts with shredded cabbage heads which is layered with salt alone. Many regional varieties exist such as curtido from El Salvador and kiseli kupus which exists in Romanian, Serbian and Croatian cuisines.

Soybeans are commonly fermented in Asia culture. For example, tofu, with its origins in China utilizes curdled soymilk extracted from cooked soybeans – then fermented with lactobacillus bacteria alongside added coagulants to give it the firmness . This contrasts to that of tempeh, a soybean cake with Indonesian origins which utilizes the entire soybeans during the fermentation – which is fermented using the mold rhizopus oligosporus for 1-2 days. White mold grows during the fermentation and essentially binds the soybeans together. Miso is the Japanese version in which salt and Aspergillus mold (koji) is combined with a grain, usually rice – where the byproducts include amylolytic and proteolytic enzymes, where the proportions define the characteristic of the final miso product. For example, miso which have more amylolytic content will tend to be sweeter. The Japanese also take the same soybeans used to make miso, but instead, they cook the soybeans for hours, then add in a bacterial culture to ferment for a short 24 hours, resulting in intact beans coated with a slimy polyglutamic acid, which is produced during the short fermentation.

Fish Fermentation

Some years ago, I was told about an urban legend about a shark dish in Iceland that is made by soaking it in its own urine for a few months before being eaten.

It turns out that hákarl (Iceland's National Dish consisting of Greenland shark or other sleeper shark, hung to dry for four to five months) is not made with urine, but instead, because of the high uric acid and trimethylamine oxide in the meat (interestingly, shark’s actually do ‘urinate’ through their skin), it is actually too poisonous to eat the meat without first fermenting it for up to 3 months, followed by curing it to remove most of the moisture. Many famous TV personalities have said this to be one of the worst things they have ever had to eat, given the extreme pungency of the ammonia smell.

While, none of the editorial team at TMS has had the pleasure of trying hákarl out so far though, I was able to try a relative of this dish which originates from South Korea not too long ago. Hongeo (홍어회) or skate (in Iceland they also make skata in a similar way) found at one of the restaurants around the famous Noryangjin Fish Market in Seoul or the famous ‘hongeo lane’ near the office towers of Yeongdeungpo, where you can be served hongeo samhap, a combination of hongeo, kimchi and tender pork belly. It was actually quite tasty once you get over the initial ammonia-like attack and the somewhat industrial-strength-like cleaning solution on your palate. The pork belly adds a bit of texture to with the fat balancing the acidity and the kimchi adding soft spiciness. Subsequently on a trip to Lake Biwa in the Shiga prefecture of Japan in Spring, I was able to try out funazushi (鮒寿し)at Shiseian in Otsu, a well known restaurant known for some of the best fermented nigorobuna (似五郎鮒) a breed of wild goldfish that has been fermented for 1 year packed with steamed rice and preserved with salt. Served complete with the roe and what I can only describe as being quite similar to a hybrid between a strong blue and a strong washed cheese.

Fermentation of fish is actually quite common; and while the above are three of the more extreme examples of fermented fish, there are numerous other examples, such as, lutefisk in Scandinavia, fesikh in Egypt, mắm cá in Vietnam.

Image Source: Ian Spagnolo

The Extreme Turducken/Gooducken

For some, stuffing a chicken inside a duck inside a turkey is fun and results in a delicious braised or roasted dish for a celebratory meal with friends. But the Inuit community living in Greenland has taken stuffing to an extreme level. Up to 500 of the Indigenous little auk birds are stuffed whole into seal skins. These are then made airtight and sealed with grease/oil and fermented for up to 7 months under rocks resulting in kiviaq. Historically linked to some botulism related deaths, this is not for the faint of heart, and the result is an intensely flavoured meat with strong cheese and liquorice characters.

The skins of animal create a natural, organic vessel in which fermentation of the meat inside can take place. In the simplest example, salami involves taking raw ground pork or beef, placing it inside its casing and then adding lactic bacteria to start the culturing process. Arctic circle communities have long used this method to ensure that during the winter months they are able to have enough food to survive the harsh temperatures where hunting or foraging is not always possible.

In parts of Northern Russia, some ethnic groups have long been fermenting the meat of walrus, seals or deer. Known as Igunaq, the meats of these animals are usually wrapped in walrus skin before fermenting by burying it in pits for a period of up to one year. The result is a pungent protein source with the smell and taste as being quite an intense cheese!

Say Cheese

Cheese is one of the largest families of fermented food products. Even the name is derived from the word caseus, the Latin word for “to ferment”, so it is difficult to say that cheese as a category qualifies for extreme fermentation. However there are some cheeses that take it an extra step. The relatively common cheese mimolette has an enhanced flavor profile due to the acarus siro flour mites that live off the surface of the cheese. Milbenkäse and Altenburger Ziegenkäse, two German specialty cheeses where the tyrophagus casei flour mites excrete enzymes after eating rye flour. The digestive juices result in a fermentation process to take place – with this process lasting up to 1 year in some cases. The mites are then consumed together with the cheese itself.

Casa marzu is the Sardinian sheep cheese that takes a standard pecorino cheese wheel with part of the rind removed. This allows the piophila casei cheese flies to lay eggs into the cheese itself. Once the larvae hatch from the eggs, they begin to eat and digest the cheese fats, resulting in an incredibly soft and creamy cheese which is to be eaten with the maggots whole.

In Modern Cuisine

There are obviously many unique fermented food products to be found around the world. I am reminded of my dining experience in 2013 at the now-closed Shiojiri Jozojo, a restaurant run by the legendary Nobuaki Fushiki, one of the leaders in the world of fermentation. He has published extensively on the science and methods around fermentation, and when his restaurant in Shibuya prided itself with its aged soy sauces up to 6 years old. There are more aged representations of soy sauce from traditional producers like 250-year old brewery Kamebishiya in Kagawa which produces a soy sauce aged for up to 50 years, and in the most extreme case, Kisoondo in South Jeolla province in South Korea, who’s family has a pot of 360-year old soy sauce.  Nonethless, even the 6 year old soy sauce by Fushiki-san has an intensity similar to tasting aged balsamic vinegar such as the 150-year old Gran Riserva balsamic from Leonardi house in Modena, Italy – made by acetifying and fermenting Trebbiano and Lambrusco grapes before storing them in barrels. Extreme intensity, concentration and balance. Not dissimilar to an aged red wine.

The miso-paste which was bordering on 50 years of age at Shiojiri Jozojo was a bit of a different animal; literally with an animalistic/gamey nose that is framed by what I could only describe as eating slightly sweet soil. An interesting experience for sure, which could be compared to having an aged red wine that has passed its prime drinking window.

Some of the fermented food items covered above may seem to be quite abstract and extreme, but more and more examples of practical but still extreme fermentation can be found in modern gastronomy. 

KOKS, the Michelin two-starred restaurant in an unobtrusive, and utterly stunning location in the Faroe Islands, uses fermentation extensively on their menu. Everything that is served is locally sourced, and as a result, local methods are found throughout their dishes. Ræst is the method of fermentation where freshly caught cod are gutted, then simply put out to hang in the open air for 6-8 weeks where it dries. The head chef of KOKS, Poul Andrias Ziska has often talked about the old traditions from these islands and this is reflected in restaurant’s famous ræst meats showcase the technique for a slow dry fermentation of the meat. At a specific 7 degrees Celsius, with not too much of a brisk wind so as to not dry the meat too quickly. Lamb intestines are fermented into a tallow paste, giving off the undeniable funkiness and strong cheesy aroma that is not for everyone, but for me, it was strangely addictive.
The Faroese tradition of ræst has even sparked a restaurant with the name. The restaurant has only been open since only 2016, but Ræst has quickly been regarded as one of the best restaurants in the Nordic circle, with strong attention to fermentations of all sorts. Lamb, fish and vegetables are commonly main ingredients to go through fermentation. 

Image Source: Claes Bech - Poulsen

About KOKS 

Pioneer of the New Nordic Kitchen in the Faroe Islands, KOKS is characterized by its unique. Faroese identity and by its commitment to sustainable and local products. Its cuisine style is earthy and refined, ancient and modern.

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