HOUGHTON — Don’t be fooled by the button mushrooms at the supermarket. Unlike a lot of produce, most mushroom varieties have a short shelf life.

“It’s kind of nice because it kind of protects it from monopolization,” Zack Osborn said during a presentation at the Portage Lake District Library Saturday for Earth Day. “It’s inherently a decentralized small-scale local good.”

That helps growers like Osborn, who sells his mushrooms at local farmer’s markets, and is also opening a new vegetarian-friendly restaurant in Hancock this summer.

And it potentially helps many of the nearly 50 people who attended Osborn’s presentation at the Portage Lake District Library, who got to take part in a cooking demonstration and also bring home their own growing kit for mushrooms.

Osborn recommended grey dove oyster mushrooms for first-time growers. They can grow in temperatures as cold as 45 degrees, allowing people to stick them in their basement.

And compared to other varieties, they’re also more tolerant of people’s mistakes. Where other types of mushrooms will succumb to molds, the oysters will more often fight them off.

“It’s really easy to look at those mushroom catalogs and be like ‘I like these, I like those,'” he said. “Don’t do it. You’re going to just have a bad experience. One thing I’ve learned is you really need to have that ‘Yes’ experience. That positive experience is going to set you up with the patience and diligence to go and experiment with other strains and varieties.”

The do-it-yourself kits provided a substrate for the mushroom mycelium to grow on. It’s about a 90%/10% split between carbon (in the form of sawdust) and nitrogen (in the form of wheat bran). Gypsum can also be added in to provide extra calcium.

Osborn also described the importance of sterilizing as much as possible, down to decontaminating the scissors provided to cut a bag open. The bag should also be pasteurized to eliminate any bacteria.

Detailed instructions on building kits at home are available on Osborn’s site at keweenaw-mushrooms.com.

The oyster mushrooms can be ready in about 30 to 50 days. This also makes it preferable for beginners over varieties like shiitakes, which can take months to grow.

Osborn also held a cooking demonstration with volunteers to show how those mushrooms can be put to use.

Some pre-stir-fried oyster mushrooms were the key add-in to puff pastries, where people wrapped in the topping of their choosing, such as spinach or feta cheese.

Osborn and volunteers also made tempura, combining shiitake mushrooms in a soy sauce marinade with egg and panko breadcrumbs — made by breaking down homemade croutons with a small rolling pin.

He finished by cooking lion’s mane mushrooms, shaggy-looking mushrooms whose meaty texture has made them popular in vegetarian versions of crab cakes.

Osborn gave the crowd tips on cooking with mushrooms. Put directly in a pan with oil, the mushrooms soak up moisture, making the food too oily, Osborn said. (This is especially true of the lion’s mane.)

Because of that, cooks should first steam-fry them in a pan to break down the chitin — a polymer that forms the cell walls giving them sponge-like properties. Once those are broken down, the cooks can add oil.

All three of the dishes will be part of the menu in some form at Osborn’s upcoming restaurant, the Shiba Cafe. It will share space with the Griffin Cafe at the Skyline Commons in Hancock, formerly the Jutila Center. Its grand opening will be June 1.

“A big part of the Shiba Cafe is going to be sourcing only local ingredients, whether it’s local specialty meats, or in the case of Niemela Market Gardens, locally grown spinach,” Osborn said. “You know it’s a warm winter, when we already have fresh spinach coming out here in the Keweenaw.”

After the presentation ended, a long line of people picked up the kits so they could start growing mushrooms for themselves.

One of them was Riikka Hepokoski of Boston Location, who came with her children. While they haven’t been growing mushrooms themselves, they pick them all the time.

“It was really nice because he first did like the cooking show, then you learn what to do with these mushrooms, and then you can maybe grow them yourself if you like the taste,” she said.