IMAGE: 2:30 p.m. in Mexico City…. time for a snack! All photos by Nicola Twilley, unless labelled otherwise.

Mexico City’s streets are dense with food vendors. Statistics are hard to come by, since the industry is largely unregulated, but in her 2007 Survey of Street Foods in Mexico City, anthropologist Janet Long quotes a survey by Reforma newspaper that found 560,000 street vendors in the city proper — an astonishing one vendor for every 8.5 chilangos.

Certainly, walking around the city it can seem as if almost everyone is eating mysterious and delicious-smelling foods on the street, from dawn to dusk. In his must-read portrait of Mexico City, First Stop in the New World, author David Lida writes that:

The sidewalk is a chilango’s pit stop, his permanent picnic. He likes to eat standing up, the aroma of sizzling meat mingling with those of exhaust fumes, putrefying garbage, dust, and sweat.

But for a Spanish-challenged gringo (such as myself), it can be hard to know where to start.

IMAGE: Wayne and Tally enjoy an El Vampiro juice each.

Fortunately, several Postopoleros (including my fellow bloggers Jace Clayton and Wayne Marshall) were lucky enough to be the guinea pigs for an amazing three-hour street food tour and tasting by a new outfit, Eat Mexico. Under the expert guidance of Mexico City native Jesica López Sol and American expat Lesley Téllez, we slowly ate our way around the triangle of streets named after rivers between James Sullivan and Paseo de la Reforma in the Cuauhtémoc section of the city.

IMAGE: The El Vampiro juice includes beets, carrots, and parsley (photo by Wayne).

We started out on fairly safe territory, although possibly too greedily, with a giant freshly-made juice each. Next on the menu were tacos al pastor, a delicious Mexican-ised pork and pineapple version of the traditional lamb gyros introduced by Lebanese immigrants in the 1930s. To quote David Lida again:

Mexico City has no indigenous cuisine, but if there is such a thing as a municipal dish, it would have to be tacos al pastor. A variation on Middle Eastern shawarma, it is made from pork, marinated with various spices, including garlic and a heavy dose of annatto, which gives it a shrill orange color. The slices of pork are mounted atop each other to form a huge orb, and impaled on a metal stick, which revolves around a vertical charcoal grill.

The exact ingredients in each taco stand’s marinade are a closely guarded secret, but various internet sources seem to suggest Coca-Cola is often involved, as well as the more standard vinegar, chiles, and orange juice.

IMAGE: “Con verduras,” i.e. served with onions and coriander (cilantro).

IMAGE: Pineapple juices drip down onto the pork as it cooks, tenderising and caramelising simultaneously.

Lesley and Jesica were fantastic hosts, armed with a chopping board and knife in order to divide each burrito, quesadilla, tamal, and taco into sample sizes, as well as a wealth of information about the ingredients, preparation, and cultural background of each food type on our tour.

IMAGE: Jesica introduces our tamal.

The street food menu has its own temporal rhythm, just as a restaurant would serve different foods at different times of day. We were lucky to find any atole or tamales left at noon, as the corn-based thin porridge-y drink and the steamed, stuffed corn-dough snack are a traditional breakfast combo. Later in the evening, Jesica and Lesley told us, tamales make a comeback, alongside camotes (boiled sweet potatoes) and elotes (corn-on-the-cob, served sprinkled with chile powder and grated cheese).

Of course, the location of street food shifts over the course of the day too. Our tour took place in a business district between 11 a.m. and 2 p.m., meaning that the streets were filled with local workers looking for something filling for a late almuerzo or early comida. In the early mornings, women selling atole frequently circulate around transport hubs to provide commuters with a light desayuno. Meanwhile, as Janet Long points out in her Survey, in the evenings, elote sellers cluster near movie theatres, and other food stands “may be set up in parks to cater to a different public than the one served during the day.”

IMAGE: Lesley prepares us for tacos de canasta.

IMAGE: Jesica even brought along a handy chopping board and knife.

Among the many foods we tried were some that I didn’t even know existed. My new favourite, the tlacoyo, is a long torpedo-shaped cornmeal pancake stuffed with beans and cheese, and in the case of the one we sampled, topped with nopales (cactus leaves) and more cheese. Later, I went back for a blue cornmeal tlacoyo, topped just with salsa. It was possibly even better.

IMAGE: Jesica purchases a tlacoyo, made to her exact specifications.

IMAGE: Tlacoya with nopales (photo by Wayne).

Tacos de canasta (or tacos sudados) are so-called because they are sold from a cloth-covered basket where they sit on top of each other, sweating. We tried one filled with cochinita pibil, a slow-cooked pork stew, and together the soft taco and tender meat formed a somewhat baby-food-like, yet delicious, mush.

IMAGE: Leslie distributes our cochinita pibil taco de canasta.

At the opposite end of the texture spectrum was our grand finale: taco de carnitas. As Angeleno food critic Jonathan Gold describes it, carnitas is basically any and all parts of the pig, “rendered and then seethed in their own lard until the surfaces caramelize, the interiors soften, and the mass reaches a sweet, succulent equilibrium.”

I must admit to being a little bit full by this point on the tour, and hence unsure whether I really needed even a small serving of pork fried in its own fat. However, Jesica invited us to sample chunks of pig skin, snout, lung, and nana, or uterus, with such charming enthusiasm, it seemed churlish to refuse.

IMAGE: Carnitas anatomy class: throat, snout (I think), skin, and uterus (the large fusilli-ish shape on the right) (photo by Wayne).

IMAGE: Tally tries the nana.

I have to confess, I did hesitate before trying the nana. For starters, it looked like a giant purplish fusilli, which defied my limited understanding of anatomy. However, as Gold correctly notes, ordering maciza (plain meat only) at a carnitas stand can’t help but feel like a character flaw:

There is nothing wrong with maciza — you may actually prefer maciza — but as when standing in line at a famous gelatería only to order vanilla, one is occasionally under the impression that there is something less than manly about the decision, that one has declined to consider the possibilities.

And of course, as it turns out, the nana really is delicious – rich and firm like a filet mignon, and not at all rubbery or iron-flavoured, which were my main fears. I felt as though I had finally earned my stripes as a genuine food blogger!

IMAGE: At the end of the tour, Lesley and Jesica treat themselves to a well-deserved taco de carnitas.

As Janet Long notes in her Survey, the food sold on the streets of D.F. is for the most part traditional Mexican cuisine: “the same basic diet based on maize, beans, squash, and chile peppers that they have been eating for well over 5,000 years.” Burgers and hot dogs are available, but seem much less popular.

According to Long, the practise of street food vending is itself traditional:

Long before the Spanish conquistadors arrived in the early sixteenth century, Aztec food vendors were setting up their stands near the Tlatelolco Market in the city, then known as Tenochtitlan, or along the canals that served as roads in the ancient city. They sold fully cooked dishes of insects, fish, and meat stews to the 60,000 people said to congregate at the great market every day.

They also sold a diversity of chile pepper sauces described by the Spaniards as “hot, very hot, very, very hot, and brilliantly hot.”

Today, each taco stands offers a similar range of salsas for those looking for what David Lida terms, “the exquisite sensation of enchilarse – to be overwhelmed by chile.” In my greedy haste, I kept eating my samples before remembering to add any salsa, although as these prepared sauces have been identified as the most likely hosts of bacterial contamination, perhaps that was not such a bad thing.

IMAGE: Big buckets of serve-yourself salsas for tacos (photo by Wayne).

Although Mexico City has always had a tradition of street food, as well as a climate that permits year-round outdoor life, Janet Long’s statistics show that the number of vendors has more-or-less tripled in the past decade. The reasons behind that expansion reveal a fascinating blend of socio-economic, political, and infrastructural forces that shape the D.F.’s landscape of mobile dining.

One factor behind the boom in street food vendors is the sprawling growth of the city itself, and its resulting nightmarish traffic. As Long explains, the city’s size and gridlock “force people to travel greater distances to their place of work or study, and make it impossible for them to return home for the mid-day meal, which is traditionally the most important meal of the day in Mexico.” Meanwhile, some recent urban arrivals “must resort to living in single rooms, without cooking facilities,” making them a captive market for taco stands and tamal vendors.

IMAGE: Tacos al pastor.

The rural-urban migration driving the city’s growth is itself a symptom of another major force contributing to the growth of a micro-entrepreneurial street vendor class. Long uses data from the Mexican Institute of Social Security to show that:

Of every ten jobs created in 2005, six were in the informal sector. [...] The formal sector of the economy cannot provide enough jobs to employ a majority of the population. [...] Unemployed workers are basically provided with two options: 1) attempt to cross the border into the United States and find work as an illegal worker or, 2) look for work in the informal sector.

In other words, street vending serves “as an escape valve to relieve the social and economic pressures created by unemployment.” With a bare minimum of capital investment, would-be workers can sell food to both support themselves and provide a source of cheap food for their fellow low-income chilangos.

IMAGE: Tacos de canasta “La Abuela” — I particularly enjoy how the Coca-Cola can and bottle are incorporated into the aesthetic.

This combination makes street food vendors politically untouchable, even though they operate for the most part illegally, without paying taxes, for permits, or even for city services — according to Long, “water can be obtained from public fountains and it is common for electricity to be obtained illegally through extensions that are attached to electric lines.”

David Lida concurs, writing that:

Since I arrived in 1990, street vendors have been a problem, and each successive mayor has announced plans to do away with them. [...] Still, tacitly, they have been tolerated. In a city where there isn’t enough work to go around, few politicians are willing to take measures that would separate people from their jobs.

So, although health regulations and vendor permit requirements exist, Mexico City’s government concludes — probably correctly — that they would be impossible to enforce, and therefore, they are universally ignored.

In other words, our tacos were an edible symptom of economic desperation, political impotence, and a city stretched beyond its infrastructural capacity.

IMAGE: A pick-up truck full of chicken parts.

Speaking of infrastructure, having just spent the morning at the Central de Abasto wholesale market, it was interesting to see the mountains of fresh produce, blocks of ice, and bags of chicken parts redistributed around the city to thousands of smaller scale vendors.

IMAGE: Blocks of ice sold wholesale at the Central de Abasto market.

IMAGE: Ice block re-sized to serve as a smoothie display stand.

IMAGE: Smaller cart-mounted ice block, complete with ice shaver to make raspados.

If supply is one aspect of the behind-the-scenes geography of street food vending, storage is another. At Foodprint NYC, for example, I was intrigued to hear panelist Sean Basinski explain that New York’s food trucks have to be taken to a Department of Health-approved garage every night, for storage and cleaning.

No such formal facilities seem to exist in Mexico City: according to Janet Long, food carts and stands are either “rolled to a safe spot at night,” or “partially dismantled at the end of the day and left on the street, where they are fairly safe, since nothing is left behind except the metal frame.”

IMAGE: Cleaning up a hamburguesa truck at the end of service.

Perhaps the most fascinating statistic in Janet Long’s Survey is that nearly half of the food sold at Mexico City’s street food stands has been prepared in a domestic kitchen. As she puts it, “There is no separation between the public kitchen and the domestic kitchen.”

The ubiquitous taco stands and baskets of tamales occupying their three-foot median along Mexico City’s traffic-clogged streets are thus a kind of distributed domesticity and an ad hoc network of unofficially-subsidised street cafeterias, as well as a tourist dining destination.

[NOTE: This post is part of a series of reports from my time in Mexico City as part of Postopolis! DF, which was presented by Storefront for Art and Architecture from June 8 to June 12, 2010.

I owe an enormous thanks to Jace Clayton for inviting me along, and to Lesley Téllez and Jesica López Sol of Eat Mexico for the tour: be sure to check out their site and follow them on Twitter @eatmexico. Lesley reports that they are currently researching a pulque/mezcal tour and a seasonal chiles en nogada tasting: both sound well worth checking out.]

IMAGE: Watermelons at the Central de Abasto in DF. All photos by the author unless otherwise noted.

IMAGE: La Central de Abasto from a helicopter. Photo by Oscar Ruiz.

La Central de Abasto de la Ciudad de México is enormous. It sprawls across a 327 hectare site on the eastern edge of the D.F., dwarfing fellow wholesale food markets such as Hunt’s Point (24 hectares), Tsukiji (23 hectares), or even the massive Rungis, outside Paris (232 hectares).

La Central has its own postcode, its own 700-member police force, and its own border-style entry gates, but during my visit, its enormity truly hit home only when we had to take a taxi to get from flowers to fish. It was a solid fifteen minute ride from one section of the market to another!

IMAGE: Border control at La Central de Abasto. Photo via.

IMAGE: Official map of La Central de Abasto.

When the Central de Abasto was opened in 1982, approximately eighty percent of Mexico’s food supply passed through its 111 kilometres of passageways. In other words, an incredible four fifths of everything that every Mexican, from Cancun to Monterrey, ate every day passed through one single site in the nation’s capital. It was “one of Mexico’s last experiments in central economic planning,” as sociologist Gerardo Torres Salcido told USA Today.

Even today, between twenty and thirty percent of the country’s food is sold at La Central. According to David Lida (whose enjoyable book about Mexico City, First Stop in the New World, contains an entire chapter on food, and who I was lucky to see in conversation as Jace Clayton’s guest at Postopolis! DF), “on a daily basis thirty thousand tons of food are trucked here from the rest of the country, and sold to three hundred thousand customers — mainly people who sell in smaller markets, to restaurants and food stands all over the city.”

In 2009, La Central was the second only to the Mexican stock exchange in business volume. Lida’s description continues:

About $8 billion a year changes hands, mostly in cash; as such, merchandisers are prime prey to kidnappers. One vendor handed over half a million dollars to have his son released from captivity. He had that much money lying around at home; it was his float.

When we arrived at La Central at 5:30 a.m. one Thursday morning during Postopolis! DF, things were still pretty busy. For the most part, traffic consists of men (cargadores) pushing trolleys or pulling handcarts at a half-run, on which anything from two to twenty pallets of mangoes, crates of canteloupes, or boxes of oranges are stacked.

If you are in their way (there is almost no way not to be), the cargadores whistle — and, by the end of our visit, I had started to notice that the pitch and phrasing of these whistles varies according to the navigational information it communicates. In other words, “Passing on your left!” sounds different from “Watch out, I’m about to cut you off.”

Their job must be brutal, particularly since the pedestrian walkways between aisles are raised up a level to allow lorries to pass beneath — a clever design that means each delivery involves negotiating several concrete ramps. What’s more, according to Lida:

The cargodores do not even earn a salary. Indeed, to rent their handcarts, they have to pay a little over a dollar a day to a character known as El Chino, a former street child and cargador himself. The workers vary between twelve and seventy years old. They charge between twenty and forty cents per box, depending on how heavy the load is and how far it has to be carried. An old man calculated that he earned about seven or eight dollars for a day’s work.

In between jobs, and as the flow of trade slows down, the trolleys double as backrests, seats, and even beds.

We began in the fruit and vegetable section, which stood out for its carefully ordered displays and fantastic signage. Oranges and potatoes were fed through a sorting machine, but even mangoes were carefully boxed by size, a task that could only have been done by hand.

Each display was topped by a sign — occasionally hand-lettered, but for the most part pre-printed. Many said fairly predictable things, like “Best Quality!” and “Lowest Price!” Others seemed to show a delightful sense of humour, such as the green beans “Without Cholesterol!” or the carrots “As Seen On TV!”

Still others professed surprise, delight, and teenage enthusiasm: “How cool!”, “This is the bomb!” and “F***ing great grapes!”

The fruit and vegetable section then spilled over into a set of open-walled pavilions, in which men and women stripped the thorns off nopales and washed carrots.

We were trying to find the flower market, but were waylaid by a corridor filled with Hallmark-style junk.

Dotted throughout the distinct sections were snack vendors, doing a brisk trade in tamale sandwiches (the cargadores need double carbs), freshly-squeezed juice, and Nescafé. I took photos of the youngest juicer and the most beaten-up pot I saw.

La Central de Abasto was designed by celebrated Mexican architect Abraham Zabludovsky, better known for his Museo Tamayo and Biblioteca Nacional. Its vast, modular forms are certainly striking, particularly when seen from above.

IMAGE: Satellite photo via Google Maps.

Frequently, however, the hangar-like shapes have been filled with a variety of random structures — storage or office spaces. The business of food distribution has generated its own forms within the shelter provided.

The scale of transactions seemed to vary wildly, with fresh produce leaving the market piled high in refrigerated lorries, ramshackle trucks, and even taxis.

La Central was built to replace an older, smaller wholesale market, La Merced, just as Rungis was built to replace Les Halles. In both cases, the market had expanded beyond its central site, and was denigrated by city officials as cramped, dirty, and unsafe. La Merced was (and still is) notorious for its underage prostitutes; Les Halles — Zola’s “belly of Paris” — was equally surrounded by rough-edged bars, restaurants, and brothels.

IMAGE: Les Halles butchers enjoying an after-work drink, Paris, 1962. Photo by Tom Palumbo via kottke.

Cities with a centralised food distribution system traditionally kept markets close to the seat of government, recognising the power of food as a political tool. That proximity was intended to help kings and ministers maintain tight control over the urban populace through the supply of food, but as cities and the markets that fed them grew, the strategy backfired. As Carolyn Steel puts it, in her excellent book, Hungry City: “By concentrating all the city’s food in one place, they created a powerhouse strong enough to defy them.”

By the 1970s, as Robert Moses rammed thirteen expressways through New York City, it seemed rational to authorities in Paris and Mexico City to start afresh, and move the messy business of food to spacious, orderly, hygienic, and purpose-built facilities at a safe distance outside town. La Central de Abasto’s stated mission is to: “Be the axis of the country’s food supply system, in order to regulate the market and offer the consumer quality and price.”

If the construction of La Central tells us a fascinating story about the evolution of governmental attempts to control food in order to tame cities, the market’s declining market share, down to handling between twenty and thirty percent of the nation’s food supply from eighty percent when it was first built, is testament to radical shifts in scale within the food business.

In other words, La Central was built to be the giant hub that tied together smallish farmers and merchants with smallish tianguis and restauranteurs. Food flowed through a single site that connected producers to vendors in a process that theoretically created greater efficiency and more competitive prices.

But following on from NAFTA in the early 1990s, food producers and vendors have consolidated and expanded in scale, shrinking the role of the hub in the middle. Walmart has set up its own supplier relationships and distribution networks; Smithfield Factory Farms is perfectly capable of finding customers without trucking its pigs all the way to a covered market on the outskirts of Mexico City.

Although supply and demand no longer meet at one central market, Mexico’s food system has not decentralised — it has just centralised elsewhere along the chain.

According to USA Today, a 2008 government report concluded that La Central was gradually shifting toward small wholesale or retail customers, “meaning it is basically just becoming a big public market.”

Trucking in food from around the country in order to truck it out again a few hours later certainly seems to make no sense in terms of Mexico City’s already disastrous congestion problems. It’s also easy to imagine the food safety issues, from terrorism to traceability, associated with concentrating eighty percent of the national food supply in a single site.

Unfortunately, the Central de Abasto system is not being replaced with a solution that makes those problems any less pressing.

Despite its transformation, La Central still preserves some of what made central markets such a vital part of the city: noise, rubbish, smells, and a heterotopic mixing of rich and poor, city and countryside. Overwhelmed by its size, chaos, and the sheer volume of food, a visitor can gain “an awareness of what it takes to sustain urban life,” to again quote Carolyn Steel.

By way of contrast, I highly recommend this gorgeous video of the clean, well-lit, and gently bleeping spaces of New York’s Hunt’s Point Food Distribution Center, as shot by fellow Postopolis! DF participant and Urban Omnibus project director, Cassim Shepherd.

[NOTE: This post is part of a series of reports from my time in Mexico City as part of Postopolis! DF, which was presented by Storefront for Art and Architecture from June 8 to June 12, 2010. I owe an enormous thanks to Daniela Hernandez, Rodrigo Escandon, and Blair Richardson, who heroically got up at 4:30 a.m. after a night of parties and concerts, in order to help me navigate La Central!]

IMAGE: Mossman Sugar Mill. All mill photos by the author.

Last month, BLDGBLOG and I joined a small group (consisting mostly of wheat farmers on a busman’s holiday) to visit Mossman mill, which is just up the road from Cairns.

As it happens, we are apparently on the brink of a sugar crisis, with the Wall Street Journal reporting that Americans might face an autumn without sugar (“Can you imagine an America with no sugar? demanded comedian Stephen Colbert in response. “Juice would contain nothing but 10% juice!”)

On this apocalypic note, then, below are a couple of highlights from our tour through Australia’s northernmost sugar mill.

IMAGE: Stage 1: Emptying billets of sugar cane into the shredder, which ruptures the cane’s cells to release the juice.

IMAGE: Each canetainer’s contents are processed separately until its sweetness level can be measured, so that the grower’s payment can be calculated correctly.

The milling process appears to begin once the canetainers are emptied into the shredder – but, in fact, the mill’s influence extends far beyond its gates, to impose a rigorous policy of sunshine equality across the entire growing region.

The rationale behind this ambitious program of solar rationing lies in the fact that the amount a farmer is paid for their sugar cane is determined by this simple equation: tonnage multiplied by sweetness. Tonnage can be increased by the usual agricultural means – fertiliser, irrigation, breeding more productive varietals, or simply sowing a larger acreage – but the most effective way to increase sweetness levels is simply to allow the cane crop more time in the sun.

The problem is that sugar cane is a highly perishable crop that needs to be processed within eighteen hours of harvest; harvest can only take place during the dry season; Mossman mill can only crush 350 tons per hour; and last year, the region produced 792,000 tons of raw cane.

As a result, nearly a fifth of the sugar cane crop has to be harvested as early as June – missing out on four whole months of sunshine. Unsurprisingly, few farmers volunteer to go first; hence the need for the mill to institute its own sunshine equalisation system. The HarvSched database combines cane type, age, and projected yield with mill capacity in order to generate a five-month-long harvesting schedule of scrupulous fairness and optimal productivity.

IMAGE: Sample HarvSched-generated solar equalisation plan.

Each farmer’s land is divided up into dozens of smaller chunks, each of which is then given its own unique harvest date. Following the HarvSched plan means that the mill receives a steady supply of sugar through the season, the farmers receive an equal dosage of sunshine relative to acreage, and the harvesting crews enjoy a regular and refreshing change of scene.

This idea of scientifically allocating sunshine seems parodically Soviet – both heroically rational and intrinsically absurd. It would make the perfect plot device for a Viktor Pelevin short story: an electromechanical engineer embarks on a quixotic mission to achieve total solar equality across the vast collectivised farms of the USSR, eventually replacing the unreliable original star with a monumental array of mono-frequency lamps and parabolic mirrors.

IMAGE: Olafur Eliasson’s Weather Project (2003), Tate Modern, via Infranet Lab.

Elsewhere at Mossman mill, scientists are at work altering the chemistry of sugar itself.

Last year, for example, food scientist Dr. Barry Kitchen managed to lower the GI, or glycaemic index, of sugar to 50. For those who aren’t South Beach Diet veterans, GI is a measure of how quickly carbohydrates release glucose into the bloodstream during digestion. High GI foods (70+ on a scale of 100) release glucose quickly, leading to blood sugar spikes, which aren’t good, especially for diabetics.

Ordinary sugar is actually only a medium GI food (65, the same as rice and sweet potatoes), but by adding more of the polyphenols, minerals, and organic acids found in molasses back into the sugar at the centrifuge stage, Dr. Kitchen managed to produce LoGicane, the world’s first low GI sugar.

IMAGES: Freshly-harvested cane being processed into cane syrup at Mossman mill.

The process was only perfected in time for the last three weeks of the 2008 crush, producing just 600 tons of this new version of sugar. That was enough to launch in the Australian market, and it’s been sufficiently popular that the Mossman mill was producing sacks of it during my visit – our sample looked and tasted like demerara.

As a next step, Dr. Kitchen and his team in the Horizon Science Shed at Mossman are also planning to use molasses to cure obesity. Incredibly, their website claims that:

Horizon Science has identified a range of phytochemicals in molasses capable of positively changing body composition. The range of molasses phytochemicals has never been previously identified because of the focus in sugar processing to produce pure white sucrose products.

When fed to animals on a high fat diet, our molasses extract has been shown to significantly reduce body fat and increase lean muscle mass.

In an alarmingly perfect inversion, it seems as though the part of sugar cane that we usually discard in processing actually reduces body fat and promotes lean muscle mass; the part we keep makes us fat and sick.

IMAGE: Sugar crystals are separated out from the molasses in which they are suspended through centrifugal force. Typically the mixture, called  massecuite, is run through the centrifuge three times – but that number can go up or down depending who the sugar is destined for. The Japanese prefer a little more molasses in their raw sugar (no doubt to bring the taste closer to their traditional wasanbon with its honey and butter overtones) compared to the South Koreans and Malaysians. Together, the three countries import the bulk of Australia’s raw sugar production each year.

IMAGE: Mossman mill

The slightly Heath Robinson, steam-era appearance of Mossman mill belies the intense innovation underway in sugar cane agriculture and processing. Indeed, the Australian government has committed to investing AUS $28 million in sugar industry research over the next seven years, citing sugarcane as “the ideal biofactory – one of nature’s most efficient converters of sunlight and water into biomass.”

Current projects range from “shoot architecture modification to boost cane and sugar yields” to genetic alterations designed “to give sugarcane the ability to express alternative, marketable products” – particularly biofuels and bioplastics (pdf).

IMAGE: QUT waterproof paper developed with sugar cane waste, with its inventors (L-R) Dr Les Edye, Dr Bill Doherty, and Dr Peter Twine, CRC CEO.

We were touring a century-old factory for reducing cane into sugar – but the sugarcane itself is the factory of the future.

Shiitake logs on racks in the Mittagong mushroom tunnel. All photos in this post taken by the author.

As Geoff Manaugh has already mentioned on BLDGBLOG, we spent our last full day in Australia touring the Li-Sun Exotic Mushroom Farm with its founder and owner, Dr. Noel Arrold. Three weeks earlier at a Sydney farmers’ market, we were buying handfuls of his delicious Shimeji and Chestnut mushrooms to make a risotto, when the vendor told us that they had been grown in a disused railway tunnel in Mittagong.

The mushroom tunnel, on the left, was originally built in 1886 to house a single-track railway line. By 1919, it had to be replaced with the still-functioning double-track tunnel to its right, built to cope with the rise in traffic on the route following the founding of Canberra, Australia’s purpose-built capital city. The tunnel is still state property: the mushroom farm exists on a five-year lease.

The idea of re-purposing abandoned civic infrastructure as a site for myco-agriculture was intriguing, to say the least, so we were thrilled when Dr. Arrold kindly agreed to take the time to give us a tour (Li-Sun is not usually open to the public).

Dr. Arrold has been growing mushrooms in the Mittagong tunnel for more than twenty years, starting with ordinary soil-based white button mushrooms and Cremini, before switching to focus on higher maintenance (and more profitable) exotics such as Shimeji, Wood-ear, Shiitake, and Oyster mushrooms.

Dr. Arrold with a bag of mushroom spawn. He keeps his mushroom cultures in test-tubes filled with boiled potato and agar, and initially incubates the spawn on rye or wheat grains in clear plastic bags sealed with sponge anti-mould filters (shown above), before transferring it to jars, black bin bags, or plastic-wrapped logs.

Shimeji (above) and pink oyster (below) mushrooms cropping on racks inside the tunnel. Dr. Arrold came up with the simple but clever idea of growing mushrooms in black bin bags with holes cut in them. Previously, mushrooms were typically grown inside clear plastic bags. The equal exposure to light meant that the mushrooms fruited all over, which made it harder to harvest without missing some.

A microbiologist by training, Dr. Arrold originally imported his exotic mushroom cultures into Australia from their traditional homes in China, Japan, and Korea. Like a latter-day Tradescant, he regularly travels abroad to keep up with mushroom growing techniques, share his own innovations (such as the black plastic grow-bags shown above), and collect new strains.

He showed us a recent acquisition, which he hunted down after coming across it in his dinner in a café in Fuzhou, and which he is currently trialling as a potential candidate for cultivation in the tunnel. Even though all his mushroom strains were originally imported from overseas (disappointingly, given its ecological uniqueness, Australia has no exciting mushroom types of its own), Dr. Arrold has refined each variety over generations to suit the conditions in this particular tunnel.

Since there is currently only one other disused railway tunnel used for mushroom growing in the whole of Australia, his mushrooms have evolved to fit an extremely specialised environmental niche: they are species designed for architecture.

Shiitake logs on racks (Taiwanese style) and mounted on the wall (Chinese style) in the tunnel.

Wood-ear mushrooms grow through a diagonal slash in plastic bags filled with chopped wheat straw.

The tunnel for which these mushrooms have been so carefully developed is 650 metres long and about 30 metres deep. Buried under solid rock and deprived of the New South Wales sunshine, the temperature holds at a steady 15º Celsius. The fluorescent lights flick on at 5:30 a.m. every day, switching off again exactly 12 hours later. The humidity level fluctuates seasonally, and would reach an unacceptable aridity in the winter if Dr. Arrold didn’t wet the floors and run a fogger during the coldest months.

In all other respects, the tunnel is an unnaturally accurate concrete and brick approximation of the prevailing conditions in the mushroom-friendly deep valleys and foggy forests of Fujian province. This inadvertent industrial replicant ecosystem made me think of Swiss architecture firm Fabric‘s 2008 proposal for a “Tower of Atmospheric Relations” (pdf).

Renderings of Fabric’s “Tower of Atmospheric Relations,” showing the stacked volumes of air and the resulting climate simulations.

Fabric’s ingenious project is designed to generate a varying set of artificial climates (such as the muggy heat of the Indian monsoon, or the crisp air of a New England autumn day) entirely through the movements of the air that is trapped inside the tower’s architecture (i.e. by means of convection, condensation, thermal inertia, and so on).

If you could perhaps combine this kind of atmosphere-modifying architecture with today’s omnipresent vertical farm proposals, northern city dwellers could simultaneously avoid food miles and continue to enjoy bananas.

Li-Sun employees unwrapping mushroom logs before putting them on racks in the tunnel. The logs are made by mixing steamed bran or wheat, sawdust from thirty-year-old eucalyptus, and lime in a concrete mixer, packing it into plastic cylinders, and inoculating them with spawn.

Fruiting Shiitake logs on racks in the tunnel. Once their mushrooms are harvested, the logs make great firewood.

The Shiitake log shock tank – Dr. Arrold explained that the logs crop after one week in the tunnel, and then sit dormant for three weeks, until they are “woken up” with a quick soak in a tub of water, after which they are productive for three or four more weeks. “Shiitake,” said Dr. Arrold, in a resigned tone, “are the most trouble, and the biggest market.”

Outside of the tunnel, Dr. Arrold also grows Enoki, King Brown, and Chestnut mushrooms. These varieties prefer different temperatures (6º, 17º, and 18º Celsius respectively), so they are housed in climate-controlled Portakabins.

The paper cone around the top of the enoki jar helps the mushrooms grow tall and thin.

Chestnut mushrooms grow in jars for seven weeks: four to fruit, and three more to sprout to harvest size above the jar’s rim.

Thousands of mushroom jars are stacked from floor to ceiling. Dr. Arrold starting growing these mushroom varieties in jars two years ago, and hasn’t had a holiday since.

Empty mushroom jars are sterilised in the autoclave between crops, so that disease doesn’t build up.

The clean jars are filled with sterilised substrate using a Japanese-designed machine, before being inoculated with spawn.

The fact that the King Brown and Chestnut mushrooms only thrive at a higher temperature than the railway tunnel provides makes their cultivation much more expensive. Their ecosystem has to be replicated mechanically, rather than occuring spontaneously within disused infrastructure.

I couldn’t help but wonder whether there might be another tunnel, cave, or even abandoned bunker in New South Wales that currently maintains a steady 17º Celsius and is just waiting to be colonised by King Brown mushrooms growing, like ghostly thumbs, out of thousands of glass jars.

Temperature map of the London Underground system (via the BBC, where a larger version is also available), compiled by Transport for London’s “Cool the Tube” team.

In the UK, for instance, Transport for London has kindly provided this fascinating map of summertime temperatures on various tube lines. Most are far too hot for mushroom growing (not to mention commuter comfort). Nonetheless, perhaps the estimated £1.56 billion cost of installing air-conditioning on the surface lines could be partially recouped by putting some of the system’s many abandoned service tunnels and shafts to use cultivating exotic fungi. These mushroom farms would be buried deep under the surface of the city, colonizing abandoned infrastructural hollows and attracting foodies and tourists alike.

A very amateur bit of Photoshop work: Li-Sun Mushrooms as packaged for Australian supermarket chain Woolworths, re-imagined as Bakerloo Line Oyster Mushrooms.

Service shafts along the hot Central line might be perfect for growing Chestnut Mushrooms, while the marginally cooler Bakerloo line has several abandoned tunnels that could replicate the subtropical forest habitat of the Oyster Mushroom. And – unlike Dr. Arrold’s Li-Sun mushrooms, which make no mention of their railway tunnel origins on the packaging – I would hope that Transport for London would cater to the locavore trend by labeling its varietals by their line of origin.

Shiitake logs on racks in the Mittagong mushroom tunnel.

Speculation aside, our visit to the Mittagong Mushroom Tunnel was fascinating, and Dr. Arrold’s patience in answering our endless questions was much appreciated. If you’re in Australia, it’s well worth seeking out Li-Sun mushrooms: you can find them at several Sydney markets, as well as branches of Woolworths.