Koji curing, which uses a kind of mould, may seem scary, but local chefs are experimenting with its use
To call koji curing a pet project for Northern Chicken chef Andrew Cowan isn’t quite accurate. ‘Pets project’ seems more apt, considering the process involves countless mould cells that, currently, work to preserve and give funk to a slab of beef Cowan’s been preserving since the start of March.
Koji has multiple culinary uses—it’s essential to make miso and soy sauce and, recently, chefs in Edmonton have found it an interesting way to marinate and cure meats. Koji curing, in short, speeds up the dry-aging process, and—ideally—out-competes other harmful micro-organisms that would otherwise grow on a hunk of raw animal matter. That said, the meat also needs to cure in a refrigerated area.
According to Cowan, three weeks after his experimental roast began to cure, it lost 40 percent of its mass, a reduction from three down to 1.8 kilograms. The curing process dehydrates the meat, he says, which helps prevent harmful bacteria growing in and on it.
The remaining mass of muscle is dryer, harder, and a deeper shade of red-brown nestled under a white layer of mould—it’s like a traditional Italian salami. It’s saltier, too, and has a very slight kick like a blue cheese—though not as intense as Cowan had planned.
Most often, koji—aspergillus oryzae, for the scientific—is most often found on grains of rice that a person or commercial manufacturer has inoculated with the fungus. While Cowan’s using it to dry age beef, it can also be used as a kind of marinade, which tenderizes meat. The mould degrades the meat’s collagen to some extent, and leaves behind a small amount of leftover flavour, says Michael Gänzle, professor at the University of Alberta’s department of Agriculture and Life Sciences.
“It’s a fairly cool translation of a traditional process to a novel product,” he says, adding that these methods don’t likely affect the nutritional value of the meat all that much, and that the process, when done right, doesn’t appear to produce harmful micro-toxins. “If you cure it outside the fridge, there can be some bacteria that comes from the meat, not the koji culture … If it’s done in a safe scenario, I don’t see any major risks for safety.”
Cowan has made charcuterie boards for years: his collections of cured meats having made their way into some Edmonton favourites like Hundred Bar and Kitchen, and Packrat Louie. Over the years, his colleagues at these establishments have gone on to do boards of their own. Cowan’s been a low-key charcuterie pro for around 10 years, but koji curing is something new for him, inspired by Instagram accounts and other sources online touting the method for its ease and quickness.
“It’s just a new technique I haven’t really tried yet,” Cowan says. “We don’t do a lot of charcuterie here [at Northern Chicken], but it’s something I really enjoy. I try to keep sharp at it.”
Cowan’s experiment probably won’t make its way onto Northern Chicken’s menu any time soon. Some of that comes down to avoiding run-ins with Alberta Health. Similarly, he says, restaurants looking to serve koji-cured meats should meticulously document the process from start to finish. Projects sporting black or red mould, Cowan says, should just be tossed out.
“If I do it at my house, for myself, it’s a different story. With customers, you have to be really careful,” Cowan says. “The way I explain it to people is: realistically-speaking, if it was unsafe, we’d all be dead. We’ve been doing this for centuries, and centuries, and centuries. You just have to be careful with it, especially when you’re serving it to customers.”
Elsewhere in Edmonton, the use of koji is more established. Biera has been making its own koji from scratch for about half a year. They order the culture online, then grow it on a food, like soybeans, and place it in a controlled environment. Over time, this becomes the miso the restaurant uses.
“I think sometimes people don’t really understand how much of a process it is from start to finish,” says chef Christine Sandford.
More recently, an Acme 140-day aged beef steak—which includes black garlic, charred leeks and shio koji—has appeared on Biera’s menu. The shio koji (koji, rice, water, and salt), which tenderizes the meat, can also let more experimental chefs use cheaper cuts of meat. In all, Sandford has seen interest in the off-kilter ingredient grow in the city.
Sandford doesn’t think koji use is wide-spread enough in Canada for anyone to really have any regulations on it and, she says, there’s not too much that can go wrong.
Alberta Health Services has a few requirements that may pertain to koji curing, though it has nothing specific on the process. Additionally, according to an email from the provincial organization, it hasn’t run into any establishments curing foods with koji during its inspections. That said, the AHS requires that a starter culture comes from a reputable source and is used according to the manufacturer’s instructions. Similarly, the AHS stipulates that food should not be subject to any contaminants during the drying process, that operators are aware of all the food safety risks involved, and that the process is documented.