River Valley Ranch & Kitchens: The Midwest’s Oldest Mushroom Farm

ericroseOperating a year-round mushroom farm, overseeing a commercial kitchen, and planning for 30-plus farmers’ markets every year results in a lot of blood, sweat, tears, and a whole lot of mushrooms. Just ask Eric Rose, it’s in his job description as the owner of the oldest commercial mushroom farm in the Midwest, River Valley Ranch & Kitchens in Burlington, Wis.

Even though he has experienced a fair share of ups and downs during the last 36 years of mushroom farming, Rose says he would have it no other way. In fact, every day that he steps foot on his 37-acre farm, he is carrying on his late father Bill’s vision of growing the finest mushrooms in the Midwest.

As a former restaurant owner in Chicago, Bill always had a tough time finding quality mushrooms for dishes on his menu. As a result, he purchased farm land in Southeastern Wis., and formed River Valley Ranch in 1976 with the impetus of providing the highest quality mushrooms to restaurants and markets. Just a few months later, Bill took Eric under his wing. Quickly thereafter, Eric was hooked and was soon tasked with running the operational side of the farm.

“I just found the whole process fascinating,” says Eric. “I really was drawn to it.”

When the farm was founded in 1976, Eric says there were 800 mushroom farms in the United States. Now, he estimates that there are less than 100; mostly in the state of Pennsylvania. What once was a two-man operation that only cultivated white button mushrooms, now employs 40 people, harvests five different certified organic mushroom varieties a week, and also grows 10 acres of pesticide and chemical free vegetables.

Mushroom Growing

Following the tenets of organic farming, River Valley grows five varieties of mushrooms (portabella, crimini, white button, shiitake, and oyster) year round in its five growing houses. In these dark mushroom houses where temperature, humidity and airflow are carefully controlled, the farm harvests nearly 7,000 pounds of mushrooms on a weekly basis – all picked by hand.


Mushroom beds in one of River Valley’s growing houses.

In each house, mushrooms begin growing in 40-ton batches of compost, produced on the farm using sustainable methods. Every 10 days the farm is supplied with 30 tons of fresh stable bedding. The farm uses this as a base for its compost, which is produced on an ongoing basis. The compost is a mixture of straw-bedded horse manure, a few different protein supplements, non-GMO soybean meal, a poultry fertilizer, gypsum, and calcium phosphate. In the beginning stage, the compost is a bright yellow wheat straw. Two weeks later, it breaks down into a dark aromatic blend that is then packed into mushroom growing trays.

Rose grows all of the white buttons, portabellas and crimini mushrooms in trays. One crop represents 176 growing trays, 22 square feet each. The trays are stacked four high just like bunk beds. After the trays are filled with compost, they get moved into a temperature controlled room for pasteurization. Pasteurization occurs as the temperature of the compost is regulated to 140 degrees for a period of seven or eight days. When the process is complete, the material gets cooled down and then the mushroom culture is introduced, says Rose.

From there, the mushrooms go through a 20-day incubation period where the temperatures are maintained to encourage mycilium, a lacy white filament, to grow. Eventually when the crop starts showing some maturity, the environment is changed, which stimulates the mushroom myclium to reproduce. Rose says it’s similar to how green plants sense and respond to daylight.


Compost prepared on site.

“Because mushrooms are not light sensitive, they don’t have that trigger, but basically if everything is done well, we see mushrooms 10 days later and pick two cycles after a 14 day period,” says Rose.

After two cycles of mushrooms have been picked, the trays are emptied, the houses are sterilized with steam, and the process starts over again.

The 40 tons of compost does not go to waste either. The farm packages it and sells it to the public at its retail store. Rose says it is an excellent fertilizer for home gardens.

For oyster mushrooms and shiitakes, the process is a bit different. Although they are also grown in mushroom houses, they don’t grow in beds like white buttons, portabellas and criminis. To grow oyster mushrooms, compost is pasteurized,

To grow oyster mushrooms, compost is pasteurized, cooled, mixed with spawn, and packed into plastic bags.

Oyster mushrooms sprouting from plastic bags filled with compost.

cooled, mixed with spawn, and packed into plastic bags. Holes are punched into the bags to allow the mycelium to breathe and the bags are set on racks in the growing houses. After about two weeks, the mushrooms pop out through the holes and can be harvested. Rose says the farm harvests 500 pounds of oyster mushrooms a week.

For shiitake mushrooms, oak sawdust is packed together into a brick shape, sterilized, mixed with spawn, and placed in environmentally controlled rooms. Mushrooms can then be harvested in about seven weeks.

Even though temperatures, airflow and humidity can be easily controlled in the inside environment, the growing process doesn’t always go as planned. Mushroom flies and diseases can easily decimate a crop so careful monitoring is very important. Pleasant surprises also arise, as was the case back in 1990 when Rose walked into a mushroom house where he was growing criminis.

River Valley Ranch & Kitchen's portabella mushrooms have been a hot item at farmers' markets

River Valley’s portabella mushrooms are popular at farmers’ markets.

“I started growing portabellas by accident some years ago when my air conditioning shut down and all the crimini mushrooms blew up into giant portabellas,” he says. “I had no idea what to do with them.”

He took them to a farmers’ market outside of Chicago and people were amazed at their size. A woman identified them as portabellas, and told Rose that chefs in Chicago were getting these mushrooms, which are a hand-sized version of a crimini mushroom, shipped in from the East Coast.

The next week he brought more to the farmers’ market and people lined up 20 deep to buy them. Rose says it was then that he started to grow portabellas on a regular basis.


Even though Rose grows mushrooms year-round, their demand in the winter months face a significant drop. With farmers’ markets pretty much non-existent due to the cold weather in the Midwest, he was often left with a large portion of mushrooms that he ended up having to sell at less than production cost. It was not healthy business for a farm that was already struggling at the time.

Eric Rose, owner of River Valley Ranch & Kitchens came up with his own unique way of pickling the leftover supply of mushrooms.

An assortment of River Valley’s pickled mushrooms.

Fifteen years ago, he thought that there had to be a better way. He came up with his own unique way of pickling the leftover supply of mushrooms. What started as just two different flavors of pickled mushrooms has expanded to more than a handful over the years. And it didn’t stop there.

In 1997, Rose opened a licensed commercial kitchen on the farm. He began producing artisan sauces, dips, salsas and pickled vegetables, using the vegetables grown there.

He takes pride in producing a superior product, so he does not use chemical preservatives or thickeners. Rose says he lets the freshness of the product shine instead. Each jar is prepared and packed by hand.

The farm’s kitchen also produces a veggie burger that is vegan and gluten free and was recently a hit at the music festival Lollapalooza in 2011. Another popular item among customers is the farm’s portabella bratwursts (a regular bratwurst that combines portabellas and Swiss cheese). Newest to the kitchen this year are vegetarian-friendly portabella tamales.

River Valley Ranch & Kitchens sells a grow-your-own mushroom kit. The kits come with everything needed, so all one has to do is follow the instructions. The kit will yield up to 10 pounds of mushrooms.

Grow your own mushroom kits are available through River Valley Ranch.

The superior quality of River Valley’s products have gained recognition by the Chicago Tribune in December 2007 as one of the 16 must-have foods for the holiday table. The farm was also featured on the Food Network’s “Food Finds” television show, where its Portabella salsa was highlighted for its unique ingredients and outstanding flavor.

River Valley’s fame and success isn’t dependent on just one person. Rose says it takes a lot of hard work and dedication from all of his employees.

“This business doesn’t operate without a lot of really good people giving 110 percent,” says Rose. “I feel real fortunate that I’ve been able to grow as a business and provide opportunity for people to do some great work and produce some good food. Employees are excited and energized and sometimes it’s hard to get people to go home.”

Where to Buy

River Valley Ranch & Kitchens’ farm store is open 364 days a year (closed on Christmas), from 9 a.m.-6 p.m.; summer hours are 9 a.m.-7 p.m.

Mushrooms and other jarred products can also be purchased on the farm’s website and at 30-plus farmers’ markets in Southeastern Wisconsin and Illinois. Click here for a list of the markets River Valley attends throughout the year.

The farm also sells a ready-to-grow mushroom kit. The kits come with everything needed, so all one has to do is follow the instructions. The kit will yield up to 10 pounds of mushrooms.

rivervalleyretailshopRiver Valley Ranch & Kitchens

39900 W. 60th St.
Burlington, WI 53105
Phone: (888) 711-7476
Email: info@rivervalleykitchens.com
Website: www.rivervalleykitchens.com

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  1. I needed to thank you for this great read!! I definitely loved every little bit of it.
    I have you bookmarked to look at new stuff you post…

  2. Love your products, the pickled buttons & the tamale (which I ate for
    breakfast)! Next I have the kale & shroom burger & the portobello ravioli
    in my freezer. & I can’t wait to give those healing lion’s mane mushrooms
    a try asap! Indeed it’s hard work for you but your creativity is shining thru’
    in your growing product line. Please know how much you are appreciated! THANK YOU!

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