There are just a few other hands-on mushroom growers at farmers markets, and to get a sense of why they are so rare, last Monday I visited Ellrott at his farm in Moorpark, 50 miles northwest of Los Angeles, where he grows mushrooms inside a climate-controlled trailer, set amid rough, scrubby terrain that's partly covered by avocado trees.
Ellrott, who at 58 has the stocky build, bald pate and ready smile of a Mr. Clean lookalike, was born in Troy, N.Y., and soon afterward moved with his parents to Ventura County. He followed his father, also named Fred, into heating and air-conditioning contracting. They bought a 40-acre property in 1978 as an investment and planted it a few years later with Hass and Bacon avocados, which they started selling at farmers markets about 1991.
Five or six years ago, after a nearby farmers market mushroom grower ceased production, Ellrott saw an opportunity and took a three-day course in mushroom growing at UC Davis. Using his skills as a refrigeration professional, he converted an old Safeway trailer, 40 feet long and 8 feet wide, installing five levels of wire racks supported by concrete blocks. (Metal structures are necessary for producing mushrooms, he noted, because wooden buildings would be colonized and destroyed by the fungi.)
Growing the mushrooms looks easy but requires some expertise. Every three weeks, Ellrott receives a pallet of starter materials, shiitake blocks and oyster mushroom bags, by refrigerated truck from the Lambert Spawn Co. in Pennsylvania.
The shiitake blocks, which are slightly larger than footballs, consist of compacted oak sawdust mixed with millet and mushroom spawn. It would be possible, but not very practical, for a small-scale grower to produce these starter blocks, since they need to be grown in a sterile facility.
After the blocks arrive, Ellrott and his longtime worker, Ramon Padilla, soak them in water for four or five hours to start the growing process and then set them out on the racks in the trailer. Within a few days they start to "pin," meaning that the small, tender fruiting bodies emerge from the dark brown growing medium, and after about two weeks they are ready for harvest.
There are three flushes of production, spread over six weeks, of which the first accounts for about 60% of production, with the largest mushrooms; the second accounts for 30%, and the third for just 10%. By the end of this period the mushrooms have consumed the nutrients and most of the weight of the blocks, which are then as light as balsa wood. He throws them out in a field, where they decompose quickly and safely.
The larger shiitakes are better for grilling, the smaller ones for sautéing, according to Ellrott. He and his wife, ReveAnn, sell them all for the same price, $16 a pound, at the Thousand Oaks farmers market on Thursday, at Ventura on Saturday, and at Encino and Santa Clarita on Sunday.
The oysters grow differently, in black plastic bags filled with straw that has been pasteurized to suppress competing organisms. They produce more heavily, and so are sold at a slightly lower price, $12 a pound.
Maintaining suitable growing conditions in the trailer is the trickiest part of growing mushrooms, Ellrott said. The ideal temperature for shiitakes and oysters, as for humans, is 65 to 70 degrees, which he maintains by using an evaporative cooler, or an air conditioner when it gets really hot. Misters come on for one minute out of every five, to maintain 95% humidity.
"It can be a challenge when we get Santa Ana winds, which are hot and dry and suck the moisture right out so that we have to step up the misting cycle," said Ellrott.
It's also not cheap; his monthly electricity bill for the mushroom trailer runs $400 to $600, depending on the time of year. To reduce this cost, many of the state's commercial producers are in cooler coastal areas.
For most of the two decades since he started selling at farmers markets, Ellrott also grew lettuce and other greens hydroponically in a half-acre greenhouse. After operating nonstop for 18 years, however, the structure required extensive maintenance, and so Ellrott cut back on production two years ago and currently grows mostly just a limited number of tomato plants in pots in the facility. Eventually he plans to restart production, but his time is limited since he continues to work during the week in refrigeration and air conditioning, and in a radon testing and mitigation business that he operates with his wife.
These other businesses are more lucrative, but he remains passionate about farmers markets and has served for the last 10 years as president of Ventura County Certified Farmers Markets, a market association founded and operated by local farmers. He also is the outgoing chairman of the Certified Farmers Market Advisory Committee, a group of stakeholders who advise the California Department of Food and Agriculture and help set the rules for farmers markets. Most recently, he is the sole farmer represented on the state's Direct Marketing Ad Hoc Advisory Committee, which is considering a wide range of issues regarding direct marketing channels, including farm stands and community-supported agriculture programs as well as farmers markets.
As an individual and on these various organizations, Ellrott has been a longstanding supporter of increased funding of farmers market inspections to ensure integrity, and he is hopeful but unsure whether the direct marketing group will come up with a viable plan before its meetings end in July.
"You have so many different entities that are represented, it's hard to get consensus," he said.