One of the businesses at the Princeton Farmer’s Market is mushrooming.
Keepsake Farm, owned and operated by Nick and Sarah Jordan of rural Princeton, has enjoyed a doubling of sales in recent years of the mushrooms that it grows.
The Jordans also bake artisan bread in a wood-fired brick oven and grow a variety of fruits, vegetables and flowers to sell at farmer’s markets.
When the Jordans talked about their business this month, they said they had sold out their last batch of mushrooms at the Maple Grove Farmer’s Market the day before.
The couple lives on the orchard land that Sarah’s father, the late Frank Foltz, had owned until he died of cancer three years ago.
Fruit trees and other trees take up much of the couple’s 27 1/2 acres and a one-acre prolific garden is located near the house. Like Sarah’s father, the couple adhere to staying away from herbicides, pesticides or chemical fertilizers.
Sarah says that most large scale commercial mushroom farms have to use a lot of chemicals to keep insects and molds out. Growing mushrooms without those chemicals can be challenging, but all important, she added, explaining that mushrooms readily soak up those chemicals which can’t be washed off.
The Jordans are experimenting with growing a variety of mushrooms but their main one is the oyster mushroom, a whitish type with gills on the underside and reaching about three inches or so across the top. The oyster name comes from the shellfish-like appearance and not its taste, which Sarah says is “distinctly mushroomy.”
The Jordans grow their oyster mushrooms indoors, and also grow shiitake, wine-cap, chicken of the woods, and a few other varieties of mushrooms outdoors on logs, stumps and wood chips. The controlled indoor conditions make the fruiting cycle much more regular, says Nick. The outdoor mushrooms are very weather dependent and may only fruit once or twice per season.
Growing the oyster mushrooms
The Jordans explained the mushroom life cycle and how they grow their oyster mushrooms.
Mushrooms grow from spores, which germinate into a white, thread-like material called mycelium. That is the vegetative part of the fungal organism and is usually not noticed because it is hidden in the substrate (ground, wood or straw). When certain strands of the organism mate, so to speak, the result is a mushroom.
Mushrooms are like the fruit of a mycelium tree and go on to produce spores, which starts the cycle over again.
The Jordans begin the process by growing mycelium in petri dishes filled with agar, a nutrient-rich medium on which the fungi thrive. When the dish is filled with fuzzy, white mycelium, the agar is transferred into canning jars filled with sterilized organic rye grain.
The mycelium then grows out of the agar, and switches to feeding on the rye until the grain is also white with the mycelium. The end result is spawn, which in the mushroom world, stands for sawdust, wooden dowels or in the Jordan’s case, rye grain, and the spawn is covered with the desired mycelium.
As soon as the jars of spawn are fully colonized and white, Nick pasteurizes straw by soaking it in 165-degree water for an hour. He then drains the water off and spreads the straw on a table to cool before mixing it with the spawn and packing it into large feed sacks. The sacks are packed close together in a dark place to incubate for two weeks. The next step is to hang the sacks in a grow house, a small outbuilding that is kept dark and humid with misters and circulating air.
The fruiting begins soon after, meaning mushrooms emerge in clusters through slits in the sacks. The first mushrooms visible are called pins, because they are so tiny, but after that they grow extremely fast. Several pickings are required per day in hot weather.
Oyster mushrooms, Sarah says, are one of the more versatile wild mushrooms because they have a distinct flavor people are used to and go well with many dishes.
People eat mushrooms for the flavor, she said, adding: “We eat them (oyster mushrooms) all the time. I love them. They have great flavor.”
The Jordans have been producing mushrooms for three years, since they returned to Princeton after living in Portland, Ore., for a time. Nick was doing network computer engineering in Oregon for Intel and Sarah continues to work as a conservation biologist for the Xerces Society. The latter is a nonprofit organization that protects wildlife through the conservation of invertebrates and their habitat.
The couple moved back to Minnesota because of Sarah’s father passed away and there was a need to maintain the farm. Sarah says it was an easy transition because of the mutual interest she and Nick have in farming.
The Jordans enjoy the farmers market movement and wanted to have something different than what is mostly found at these markets. They also went with mushrooms because they have been teaching classes for several years on edible wild mushrooms.