The 12-Hour Mushrooms

Brandon Cowen’s 12-hour smoked king oyster mushrooms spend twelve hours on a two-zone fire and three more resting in butcher paper, and the only thing in the entire process he actually measures is the salt. Everything else he does by eye, by smell, and — at the end — by pushing a bamboo skewer into a mushroom stem and paying attention to what it tells him.

I have been eating this once a year for six years and asking for the recipe for five of them. There isn’t one. There has never been one. So this past Canada Day I drove out to Port Alden — an hour west of Toronto, right on the lake — at half past four in the morning with a notebook, a folding chair, and a thermos, and I stood in Brandon’s yard for fifteen and a half hours writing down every single thing he did. This post is that notebook, cleaned up, with the quantities back-calculated from a kitchen scale I brought without telling him.

The oil drum, and the first Canada Day

The first year was 2014 and the cooker was a fifty-five gallon drum that had previously held marine grade degreaser. Brandon Cowen found it behind a boatyard on Dunmore Street, cut a door in it with an angle grinder, drilled an intake, welded on a rack from a wrecked oven, and burned it out clean over three days of hardwood fires before he would put food anywhere near it.

That drum is still in the yard. It is now a planter with a rosemary bush in it, and the door still swings. When I asked whether he had known what he was doing, he said no, and that the first batch had been “objectively bad in an interesting way” — too much white smoke in the first two hours, which is the single most common mistake anybody makes, and one you can taste for a week afterwards.

He has cooked this every Canada Day since. Two of those years it rained hard enough that he ran a tarp on poles over the cooker and stood under it by himself for most of the afternoon. Nobody in Port Alden finds this odd any more. Around three in the afternoon people start turning up at the fence with folding chairs.

Why Brandon Cowen won’t call this barbecue

He will not use the word, and this annoys people. It annoyed a man at the fence for a solid ten minutes on the day I was there.

“Barbecue is a specific thing that specific people spent generations getting right,” Brandon said, without putting down the tongs. “This is something I do with a fire and some mushrooms. It borrows the fire. It doesn’t get to borrow the name.”

I have watched three separate people try to argue him out of this position and none of them have got anywhere. He is polite about it and completely immovable, in the same way he is immovable about the rest. When he was asked, at the fence, what he does call it, he thought for a second and said, “Thursday food that takes until Friday.”

People land on this page searching for vegan barbecue and I do understand why. There is nothing animal in this recipe — no butter in the wrap, no stock in the spray, nothing hiding in the rub. But that is not a modification of anything and it is not a stand-in for anything either. It is what he cooks. It has been what he cooks since the drum.

The salt ratio, which is the only thing he measures

Here is the number, and it is the one part of this post I would ask you not to improvise on: half a teaspoon of coarse kosher salt per pound of mushrooms, and exactly twice that much coarse black pepper.

For eight pounds of king oysters that is four teaspoons of salt and eight of pepper, and it looks like nowhere near enough when it is sitting in the bowl. It is enough. King oysters are around ninety percent water and a dry brine at this ratio pulls a surprising amount of it to the surface in half an hour, which is what gives you something that will actually take colour instead of sitting there steaming.

Two cautions. First, this is measured in Diamond Crystal kosher salt, which is a light, flaky salt; if you are using a denser brand, use about two-thirds as much by volume, or weigh it at roughly 2.4 grams per pound of mushrooms. Second, the pepper has to be coarse. Sixteen mesh, cracked, gritty between your fingers. Fine pepper in this quantity is unpleasant and will taste scorched by hour four.

Two zones, one fire

The setup has not changed since the drum, and it is the whole technique. All the fuel goes to one end. The food goes to the other end. Nothing burns underneath the food at any point in the twelve hours. A water pan sits between the two, which does less for humidity than people claim and a great deal for holding a steady temperature when the wind comes off the harbour.

Vents: intake open about a third, exhaust wide open, always. If you find yourself closing the exhaust to control temperature you will get white smoke and the food will taste like an ashtray. Take fuel out instead.

The plateau, and when to wrap

Somewhere around hour two and a half, the mushrooms stop getting hotter. They will sit at about 165 to 170 °F for the next four and a half hours and refuse to move, because every calorie going into them is being spent evaporating water off the surface rather than raising the temperature inside. This is the same physics that gives every long cook its plateau, and it is where most people panic, crank the fire, and ruin the outside.

Do not do that. Brandon does not even own a probe thermometer for the food — the only dial in his yard reads grate temperature. His signal for the wrap has nothing to do with degrees: when the mushrooms stop taking on colour, they are finished with the smoke, and it is time to wrap. On a normal year that lands around hour seven. On a windy one it can be six.

Pull by feel, not by clock

From about hour nine he starts checking, and the check is a plain bamboo skewer pushed into the thickest part of the stem, right at the base where the flesh is densest. Not the middle. The base. Early on it feels like pushing into a raw potato. When it is ready, the skewer goes in like the mushroom isn’t there.

He checks two or three of them and takes an average, because they are not all the same size and they will not all finish together. On the day I was there the whole batch came off at eleven hours and fifty minutes. Two years ago, he says, it was thirteen hours and ten, and it was the best batch he has made.

“The clock is a guess and the thermometer is a different guess,” Brandon Cowen said. “Your hand isn’t guessing. It’s the only one of the three actually touching the food.”

The rest is part of the recipe

Three hours. In the paper. In a dry cooler with a towel over the top and absolutely no ice. Every year somebody tells Brandon Cowen this is excessive, and every year he ignores them, and every year the people who have eaten it before quietly agree with him.

What the long rest does is let the moisture that got driven to the centre redistribute back out through the fibres. A mushroom sliced twenty minutes off the smoker sheds everything onto the board. The same mushroom after three hours holds it. That is the entire difference and it is enormous.

Then you slice across the fibres at about three-eighths of an inch, spoon the tray juices back over, and put it on the table with white bread, pickles, raw onion, and nothing else.