Everything I Learned About Truffles in a Week

It’s truffle season in China right now. Who cares? Don’t Chinese truffles suck? Aren’t they just flavorless little fungus nuggets masquerading as real (French!) truffles, colluding with synthetic truffle oil and immoral chefs to ruin our dinner? I don’t know! Or, I do know. I spent a week talking to chefs and truffle scientists, and reading dozens of scholarly papers, to achieve a veneer of knowledge. Now that I have finished and crawled out of my mycelial dirt hole, I present it here, to you, you filthy mushroom sniffer.

The first Chinese black truffle wasn’t from China. Instead, a dried sample of the underground mushroom was sent from what is now the Indian state of Uttar Pradesh to England, where botanist and mushroom enthusiast Mordecai Curbitt Cooke described it in an 1891 scientific journal as a Himalayan truffle. In honor of its provenance, he named it after the subcontinent: tuber indicum.

It was a minor discovery, another member of the global truffle family, which we now know lives on every continent except Antarctica and whose classified species number in the hundreds. But it wouldn’t be known in China for another hundred years, when the black, bulbous tuber was dug out of a Sichuan pine forest in 1989. Named tuber sinense by the Chinese scientists tasked with its description, today we know that it was, in fact, part of the broader tuber indicum family: the Chinese black truffle.

Derided as a fraud, a fake and a rip-off of its European counterpart, the expensive Perigord black truffle (tuber melanosporum), the poor Chinese black truffle has only been known for three decades and has spent much of that time maligned as a flavorless, unscented imposter. The truth, as usual, is more complicated.

Truffles go back in history to about 156 million years ago, the era of pterodactyls and stegosaurus dinosaurs, when the earth’s single land mass, Pangaea, was splitting into two. Initially an aboveground mushroom, they went into hiding underground, becoming, as they are called in the mycology world, hypogeous.

Some speculate it was to escape the weather (they are better insulated in the dirt), others that going belowground actually helped them to be eaten by animals like squirrels and wild boar,who would then spread their spores through their feces.

Whatever their reasons, they continued having mysterious truffle sex — I will explain; it doesn’t have anything to do with that Nicki Minaj song — and reproducing, breaking off into different families, and spreading around the world. They lived a quiet existence in the soil and roots of pine and oak forests for millions of years until humans came along and started digging them up.

Everyone from the ancient Babylonians to the Romans ate truffles and theorized on their origins. A disciple of Aristotle guessed they came from flashes of lightning. A Greek poet theorized they were born from silt and transformed through internal heat. For more than two millenia, they remained a mystery to the humans who dug them out of the forest and ate them.

And then, in 1808, French farmer Josef Talon figured out how to farm them. The golden age of the European truffle began.

(Truffle sex: Truffles are either male or female and in order to procreate and produce more truffles, they have to have sex somehow. That’s difficult, because like middle school cafeterias, they separate into same-sex cliques. So, all the truffles around one tree might be male, but then all the females are over there around another tree might be female. They cluster. The problem is: truffles don’t have feet. So how do they meet and make baby truffles? It’s an ongoing question in science, according to the research I read. Scientists still don’t really know. Mysterious truffle sex!)

Today, the Chinese truffle business is far larger than the more well-known European black truffle business, whose harvests are in decline as climate change warms the planet and rainfall decreases. Some estimates put modern tuber melanosporum harvests in Europe as low as 20 tons per year, while tuber indicum harvests are more like 1,000 tons per year, according to one scientist I talked to.

(Though there are truffle farms in China, they are still experimental. That means all commercial truffles in China are wild. It also means that no one is consistently or accurately tracking the actual output or value of the truffle industry, as truffles are sold informally at local and regional mushroom markets.)

This shift in global truffle production is only likely to speed up. In another study from 2019 in Science of the Total Environment, scientists modeled shifts in temperature related to global climate change and predicted that the southern European truffle — tuber melanosporum, the expensive Perigord truffle — may become extinct as soon as 2100.

But does anyone want a Chinese truffle in the first place?

The Chinese black truffle, tuber indicum, and the southern European tuber melanosporum are cousins. They look alike. They grow similarly. But telling them apart is difficult, even for scientists with microscopes and too much time.

I have spent days reading through journal articles with titles like Food Authentication: Species and Origin Determination of Truffles (Tuber spp.) by Inductively Coupled Plasma Mass Spectrometry and Chemometrics.

Other methods I’ve come across, all in studies trying to tell the two cousins apart: matrix-assisted laser desorption/ionisation time of flight mass spectrometry (MALDI-TOF-MS); Fourier transform near-infrared (FT-NIR) spectroscopy; stable isotope ratio analysis (to determine their stable carbon, nitrogen and hydrogen isotope ratios); sterol fingerprint identification; and capillary gel electrophoresis.

Companies specialize in DNA testing truffles to tell which variety you may have.

Why?

Money, of course. Tuber indicum is significantly cheaper and way more abundant. According to Truffle.farm, a website that tracks average truffle price, the retail price for tuber melanosporum was nearly 20 times the price of tuber indicum (21,300 rmb per kg vs 1,100 rmb per kg) in 2019. It’s easy to see the attraction for unscrupulous vendors to try to substitute tuber indicum for tuber melanosporum.

In one strange twist in my research, I found a truffle hunter in southwest China who claims to have found tuber melanosporum growing in Sichuan in 2018. A contentious WeChat conversation followed, in which I asked him for some type of proof that he had made such a historic and scientifically implausible discovery.

He insulted the scientists I consulted, who called it “impossible”; insinuated that I was working on behalf of the Italian Urbani family, which controls 70% of the world’s black truffle trade and is not friendly to Chinese truffles; brushed off any concern that he was the only one to ever find this truffle and it just happens to benefit him financially; produced a single China Customs certificate that identified his product as tuber melanosporum (China Customs are neither botanists nor mycologists and do not perform DNA tests on truffles to determine the species — it was likely a taxonomic mistake);  claimed his financial or logistical limitations were too high to send his newly discovered “Chinese melanosporum” for any actual test that might confirm his discovery; failed to produce any theory for how tuber melanosporum, which has only ever been found in France, northwestern Italy and northwestern Spain, and is known to be a species European in origin, appeared, wild, in his backyard but nowhere else in the world; and just generally went off the rails with distractions, obfuscations and personal accusations against me.

In his defense, a chef friend of mine who has seen samples of the truffle in question confirmed it was more aromatic and more similar-looking to a European truffle than previous Chinese truffles he had seen. It is always possible that a truffle hunter discovers a new species, when there are so many types in China, and that this species might even bear a stronger resemblance to tuber melanosporum.

That still wouldn’t make it a tuber melanosporum, and the circumstances surrounding this particular instance, and the way the truffle hunter reacted to my questions, coupled with the obvious potential for financial benefit and the history of fraud associated with Chinese truffles, just smell off.

If the truffle hunter is correct, he will have proven the Chinese and European mycology fields wrong and upended what we know about the geographic distribution of species between Europe and Asia. He will also have made a tidy little profit. Seems to me the burden of proof for such a claim rests on him.

In my conversation with him, all he had was vitriol.

In researching this article, I found all kinds of references to China being the capital of “cheap knock offs” and Chinese truffles being a “cheap knock off” of French truffles, as if anyone could suddenly engineer an organism that dates back to the late Jurassic period. In academic papers, tuber indicum was sometimes described as “valueless”.

Six years after the discovery of tuber indicum in Sichuan’s Huidong County, The New York Times published a 900-word story headlined The Invasion of the Chinese Truffle describing chefs who had been “ambushed by Chinese truffles”.

Interestingly, I suppose, no such cultural stigma was attached to truffles from Africa — the desert truffles of Morocco and Tunisia, the Kalahari truffles of Namibia and Botswana, the farmed melanosporum of South Africa — or the Middle East, where they have been used in medicine for centuries. (Truffles have high anti-oxidant, anti-tumor and anti-inflammation levels.)  

Racist posturing aside, there are differences between tuber indicum, the Chinese truffle, and tuber melanosporum, the Perigord truffle. The most important is aroma. And here is where things get quite complicated.

Chinese truffles do have an aroma, depending on a wide range of biological and environmental factors, such as soil composition and pH, nutrient sources, residual farming chemicals, genetics, humidity, storage conditions, their microbiome and the geographic location where they are found.

(Though tuber indicum are most closely associated with Yunnan, Sichuan and Tibet, they — or a close cousin, tuber formosanum — have also been found in Heilongjiang, Jilin and Hebei recently. Even then, some will tell you that those from Yunnan’s Gongshan county, on the border with Tibet, are the most fragrant.)

Again, back to the scientists and the literature.

In Mushrooms, Humans and Nature in a Changing World, a book published in 2020, science found that quantities of volatile organic compounds, and especially sulfur compounds and ketones, increase while aldehydes decrease as truffles mature. Only mature tuber indicum contain 2-methyl-1-propanol (up to 19%), a very important component of truffle flavor.

And here’s the catch: maturity.

This is where the biological limitations of tuber indicum are compounded by human behaviour, to everyone’s long-term detriment.

How?

Truffles are part of a symbiotic ecosystem that grows among the roots of their host trees, typically pine and oak. They are a network, a web, and the truffle that we eat is just the most visible manifestation of that web (in mycology speak, the truffle is the “fruiting body”).

To the people harvesting truffles in China, that delicate symbiotic relationship often doesn’t matter. Unlike Europe, where truffles are hunted with dogs who are trained to find ripe truffles, in China, truffle hunters use hoes to scrape the forest floor as early as August (truffles mature in fall and winter). When tubers are found, the entire area is scoured and all the truffles are harvested, regardless of maturity.  

Blame the lack of training or regulation, the relatively short history and unfamiliarity with the truffle, or the potentially high financial rewards (even if they pale in comparison to tuber melanosporum); it all results in unsustainable harvertising and significant damage to the ecosystem.

So much so that in the thirty-odd years that have passed between that first Sichuan truffle discovery and today, wild Chinese truffles have gone from unknown to villains to now being rated as “vulnerable”, one step below “endangered” on the government’s Red List of Biodiversity, along with several other threatened truffle species.
 
So the answer is, yes, Chinese black truffles do have an aroma. Yes, it’s closely tied to maturity, as a 2013 study in the journal Mycosystema noted: unripe tuber indicum emit just four aroma compounds while fully mature tuber indicum emit thirteen (dimethyl sulfide, 2,3-butanedione, 3-methylbutanal, 2-methylbutanal, hexanal, and 1-octen-3-ol are the main ones, in case you want to make one at home).

No, it doesn’t rival the Perigord truffle in the minds of many chefs I spoke to. But the degree of that aroma is tied to so many factors, big and small, that the quality of any given truffle can vary wildly. So both the naysayers who call them “aroma-less” and the supporters who use them in some manner (and I spoke to several well-respected French and Italian chefs in Shanghai that do) may be right. They just had different truffles.

These days, Chinese black truffles have gone completely mass market. Shake Shack launched a black truffle menu in November 2020 with truffled burgers and fries. Bi Feng Tang uses them in multiple ways. You can buy them on major online sites including JD.com and Taobao. I can get dried Chinese black truffles delivered to my door in an hour through the Hema app on my phone.

And yet we still hardly know them. China has so many types of truffles it’s still discovering new ones at major commercial markets in capital cities (and even white truffles in Sichuan — a topic for another time).

In 2020, two scientists in Yunnan found purple-black truffles mixed into a batch of tuber indicum at a Kunming mushroom market, and took them back to the lab. After a quick analysis, they discovered the tubers were previously undescribed: two new species.

Illustrations: Cheesecake

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A Few of the Resources I Used in Researching This Piece

The Invasion of the Chinese Truffle, by Florence Fabricant. 1995. The New York Times.

Chinese Black Truffle-Associated Bacterial Communities of Tuber indicum From Different Geographical Regions With Nitrogen Fixing Bioactivity by multiple authors. 2019. Frontiers in Microbiology.

The Black Truffles Tuber melanosporum and Tuber indicum by multiple authors. 2016. True Truffle (Tuber spp.) in the World.

Nutritional value and antioxidant activity of Chinese black truffle (Tuber indicum) grown in different geographical regions in China by Xu Baojun, Wu Ziyuan and Mandiner Meenu. 2021. LWT – Food Science and Technology.

Potential aromatic compounds as markers to differentiate between Tuber melanosporum and Tuber indicum truffles by multiple authors. 2013. Food Chemistry.

Food Authentication: Species and Origin Determination of Truffles (Tuber spp.) by Inductively Coupled Plasma Mass Spectrometry and Chemometrics by multiple authors. 2020. Journal of Agricultural and Food Chemistry.

Mushrooms, Humans and Nature in a Changing World (book) by multiple authors. 2020. Springer.

Distribution of Tuber indicum in Northeastern China and Its Ecological Significance by multiple authors. 2019. Acta Edulis Fungi.

Species Recognition and Cryptic Species in the Tuber indicum Complex by multiple authors. 2011. PLOS ONE 6.

A new species of the genus Tuber from China by Tao K, Liu B, Zhang DC. 1989. Journal of Shanxi University (Natural Science Edition).

Himalayan Truffles by M.C. Cooke. 1891. Grevillea, A Quarterly Record of Cryptogamic Botany and Its Literature.

Two of the People I Spoke To and a Website I Reference

Yu Fuqiang, Vice Director, Kunming Institute of Botany, Chinese Academy of Sciences

Wang Yun, retired professor, Member Royal Scientific Society of New Zealand, Botanical Society of China (member councils), North America Truffling Society (honorary life)

Truffle.farm, a website which hosts a truffle price tracker