BTTR Ventures, a self-styled "socially responsible" company, sells a mushroom growing kit on their web site for $19.95. They have a good story behind it. They collect coffee grounds that otherwise would have gone to waste and use them to grow oyster mushrooms. This doesn't break any new ground - people have been doing this for some time, in different ways. But they have done a great job of getting favorable press all over the place, catching the wave of interest in local food and sustainability.

Their web site is peppered with quotes from celebrities like Alice Waters and Carson Daly. At present they claim to have "diverted & transformed over 260,000lbs of coffee grounds into a rich soil for gourmet mushrooms" and "helped families grow 45,000lbs of fresh mushrooms at home." It almost sounds too good to be true. I wondered what I could learn from these bright, idealistic young guys about running a successful mushroom-growing business. I ordered one of their kits.

Their web site claims a kit will produce "Up to 1 lb per crop" of pearl oyster mushrooms, and "multiple crops (at least 2, though some customers have got up to 4)." That clearly implies you can get between one and several pounds of mushrooms from a kit. As soon as mine arrived, however, I knew I'd be exceptionally lucky to get even a single pound of oyster mushrooms out of it. 

The kit consists of a box with a cut-out through which the mushrooms emerge. Inside the box is a 38 oz. bag of substrate, the medium the mushrooms grow in and consume, already inoculated with oyster mushroom mycelium. Over a few weeks I got three crops. The first crop weighed 4 oz., the second 1.6 oz., and the third, 0.9 oz., for a total of only 6.5 oz. Did I do something wrong?


I didn't. In fact, the result was about what I expected. The mushroom growing industry has a standard for measuring how well a mushroom strain converts substrate into mushrooms. It's called "biological efficiency": when a mushroom converts a pound of wet substrate into a quarter pound of usable mushroom caps, we call that 100% efficient. In his book Growing Gourmet and Medicinal Mushrooms, mycologist Paul Stamets explains that, while higher efficiencies are possible under ideal conditions, a good grower should operate "within the 75-125% range."

To get a single pound out of my 38oz BTTR kit, the mushroom would need to be 168% efficient. This falls well outside the normal "good grower" range. To get the 2, 3, or even 4 lbs they lead you to expect, you'd need biological efficiency in the range of 300% - 650%, which just doesn't happen. I got 68%, a little disappointing, but not unreasonable. Under different conditions you might get an ounce or two more. I do not believe anyone ever grew a pound of mushrooms with one of these kits.

Clearly, BTTR shamelessly exaggerates what their kits can do. Some would consider this outright fraud. Certainly a genuinely "socially responsible" company would not do that. Imagine if you sold cars, and claimed yours could get 50 MPG when you knew it only got 20.
We could give them the benefit of the doubt, and assume they just didn't know any better. But no "socially responsible" company would make such claims without even testing them. Ignorance is inexcusable here.

Still, who really cares? They're just little mushroom kits, right? The customers have fun, and learn about growing mushrooms. Why make a stink about it?

Two reasons. First, customers may get the wrong message. Consider this review of BTTR's product on "The box is much smaller than I had envisioned and the growth to date is minimal. I purchased a button kit around the same time with a much larger box and so far much more growth. I am going to stick with that type in the future."

That customer learned the wrong lesson. He thinks growing oyster mushrooms is no good. Others will just think that growing mushrooms productively is beyond them, or that it's too expensive - and at about $45 a pound for the final product, a BTTR kit is ridiculously expensive. Deceitful marketing claims poison the well for everyone in this business.

Second, and more important, honesty matters. Promoting your business with false or exaggerated claims completely contradicts the whole idea of a moral enterprise. Treating values like sustainability and social responsibility as empty advertising slogans devalues them and betrays the people who believe in them, and who trust you with their patronage because they believe you share their values.

When you get people to support your business because they believe you operate a moral enterprise, you had better, in fact, run your enterprise according to the principles you espouse.

Incidentally, we offer our own oyster mushroom-growing kits, starting at $15, at The Imaginary Farmer Store. Responsibly grown and marketed, the kits contain 5.5 lb (or more) of  substrate, which you can realistically expect to yield between 0.9 and 1.6 pounds of mushrooms.