Where are the fields of portobello and maitake? A rare look at Kennett Square’s mushroom houses.

Restaurateur Aimee Olexy is used to delivering disappointing news to those eager to know more about her hometown.

“Are there mushrooms just growing everywhere?” they’ll ask about Kennett Square, famously dubbed the mushroom capital of the world.

“Yeah, but they’re in cement houses,” she tells them. “It’s mushroom farming, mushroom agriculture. That is always a mystery to people that are even very much from this area, like here visiting Longwood [Gardens]. They’re like, ‘Where are the mushroom fields?’”

Olexy is the enduring force behind Talula’s Table, market/cafe by day and home to one of the region’s most elusive dinner reservations by night — a claim few 15-year-old restaurants can make. The coveted 10-course tasting menu changes every six weeks, but there is always a mushroom course. During the day, customers can buy all sorts goods featuring fungi: mushroom mac and cheese, risotto, soup, ravioli, porcini pasta trumpets, truffle oil, and chagaccino, a mushroom powder-infused cappuccino.

To some degree, Talula’s success has been intertwined with the cash crop from the start. “It’s kind of like the spirit of Talula’s Table, the mushroom,” she says. The town’s fervor in celebrating the local ingredient is partly why she planted the restaurant here, rather than, say, Avondale.

But Olexy has always been “a little bit mushroom-y.” She grew up in West Chester, so she’s known the purpose of those windowless cement houses — “Pennsylvania doubles,” they’re called — since she was a kid. She remembers waiting at the bus stop, the smell of mushroom fertilizer hanging in the air, the sound of commercial trucks driving by. (Another credential: “I’m an old Deadhead hippie.”)

That deep background makes Olexy an apt ambassador for a tour of Phillips Mushroom Farms, a fourth-generation grower and one of Talula’s suppliers. The Phillips family operates The Woodlands, a mushroom-centric gift shop in a 19th-century farmhouse. The store sells eight kinds of fresh fungi, woodsy arts and crafts, and inventive foods, including mushroom ice pops specially made by La Michoacana ice cream shop.

Olexy often steers day-trippers to The Woodland’s mushroom museum, which affords a glimpse into what goes on in Kennett’s rarely-seen mushroom houses. The mystery is out of necessity: “We’ve got so many hoops to jump through and we’ve got to keep it really clean,” explains Phillips grower Peter Gray. “It’s not going to hurt to have a few people walk through, but having hundreds walk through — it’s a food-safety issue.”

(Years ago, Kennett Square farmers would “basically donate a house” for tours during the Mushroom Festival, Gray says. “They’d have 700 or 800 people walking through this house over the weekend and everybody’s touching stuff, so that all got thrown in the trash.”)

It’s cool, humid, and slightly claustrophobic inside one of Phillips’ original Pennsylvania doubles. Rods of fluorescent lights illuminate a network of wooden beds that stretches two stories high. The beds are filled with compost that’s been “cooked,” or pasteurized, then laced with mushroom spawn. It feels still here, but thousands of cremini and portobellos are quietly doubling in size every 24 hours.

In the space of a couple weeks, the spawn will germinate, then knit together into mycelium, a dense, pale-white web of fungi that colonizes the nutrient-rich compost. The compost’s temperature and moisture are closely monitored. The beds are watered daily; determining how much is an art.

Soon, tiny pins will penetrate the top layer of sterile peat moss. A pin becomes a button, a button becomes a mushroom, each one the fruit of the fungi.

When they’re mature, the growers drop the carbon dioxide level in the house to trigger the first and most prosperous of three flushes, or harvests. “We’re tricking [the mycelium] into thinking it’s going to die and it’s time to reproduce,” Gray explains. After picking, they’ll allow the pins to grow again and the cycle repeats. After nine weeks total, it’s time to clear out the compost, steam everything clean, and start fresh.

Mushroom-growing technology has advanced a lot in recent years. Nearly everything can be automated, from filling the beds to picking. Handpicking is still prevalent in the U.S., where 85% of mushrooms are sold fresh. But automated harvesting is gaining ground, Gray says. “It’s like a lawn mower you put on a bed and they just cut everything off.” It’s already the dominant practice in Europe.

Phillips’ mushrooms are still handpicked and hand-packed to maintain their pristine condition, but the business has modernized in other ways. Its old-school doubles feel rustic next to its optimized aluminum houses, home to its specialty mushrooms.

Instead of wooden beds teeming with dirt, there are metal racks lined with substrate-packed plastic bags, frilly maitakes, and shaggy lion’s manes sprouting out of the corners. In another room, yellow oyster mushrooms bloom out of black plastic-wrapped pillars of mycelium. Mist descends from the ceiling, blurring the fluorescent light and the other side of room. There’s a distinct horror-movie vibe to the whole affair.

Olexy concurs. “I should bring M. Night Shyamalan. He would love it.”

Though it seems an unusual setup, it’s thoroughly vetted. The farm grows up to 30,000 pounds of oyster mushrooms alone per week. “You can grow these in bottles or jars. [But] we’ve found that this is the most efficient way for us to maximize yield, space, processing,” says Sean Steller, a fourth-generation Phillips grower and the farm’s director of business development.

While mushrooms already had a following among restaurateurs like Olexy, Steller says specialty mushrooms took off with consumers during the pandemic. Retailers like Whole Foods started stocking meaty maitakes and mild lion’s mane mushrooms (which easily pass for lump crabmeat when flaked apart) for ambitious home cooks who wanted to replicate restaurant dishes.

That’s a contributing factor to a well-documented “mushroom boom,” a trend that’s extended beyond the culinary realm into wellness, fashion, and art. The stores on State Street in Kennett Square offer proof, with mushrooms printed on pillowcases, onesies, aprons, socks, and potholders. Kathi Lafferty, owner of the Mushroom Cap gift shop, says there was no such mushroom memorabilia when she opened in 2004. Now, “you can find everything.”

Explanations are myriad: It could be mushrooms’ health properties, their umami punch, their psychedelic capabilities, their environmental positives. Whatever the reasons, it’s all gravy for Kennett Square.

“Mushrooms are having their moment,” Olexy says.