There are two main methods of producing Shiitake mushrooms:
The fast way is by inoculating fake “logs” made out of sawdust and grains (called blocks) and incubating them for a few months in a controlled, indoor environment.
The good way is by choosing the right wood, inoculating a real log, and growing it in its natural habitat where it can soak up more than twice as many nutrients (and better tastes!) than the sawdust blocks.
These wanna-be logs are sterilized, inoculated, and then kept indoors with artificial light, wind, and temperature. Chemicals, minerals, and urea are usually required to boost the nutritional content of the mushrooms. The blocks are extremely susceptible to disease, attacks from other fungi, and insects. Oftentimes, growers will use pesticides or fungicides to control bugs, disease, and other invading species.
Just like the rest of the food you eat, you want it to be natural and nutritious. Unfortunately, by using sawdust blocks, the nutritional and organic value of the mushrooms is drastically decreased.
Benefits of Log Growing
Yes, it’s true that growing mushrooms on logs takes longer, but the benefits far outweigh that issue. There is a reason that markets sell log-grown mushrooms for a higher price than others; they’re simply better in just about every way.
First of all, each mushroom log can produce up to 4 years with increasingly larger crops. This is many more crops per one log than per one sawdust block. Also, each log harbors its own immune system so that invading fungi species, bugs, and disease are almost never a problem. It takes care of itself, even when exposed to outside conditions.
Once a log is finished producing mushrooms, it can either be recycled and used again or used for firewood. It’s a completely environmentally friendly process that includes no pesticides, fungicides, or artificial conditions.
The Grocery Stores Are Tricking You
In Japan, where knowledge of the shiitake growing methods are more well-know, consumers will pay $4 per pound of sawdust-grown mushrooms but upwards of $40 per pound for natural, log-grown specimens.
In America, we pay the same price for both. In fact, the majority of mushrooms you’ve purchased at the supermarket have been grown with blocks, not logs. Most log-grown mushrooms go to professional chefs or pharmaceutical companies. This is an absolute rip-off for consumers and most people have no idea it’s happening. In fact, most people really have no idea what a real shiitake mushrooms looks like since they may have never seen a real one.
How To Tell The Difference
There are three easy ways to tell whether your mushrooms were grown on a log or a block:
Size and Shape
If you’ve purchased a package of mushrooms look at how they differ from one another in shape and size. If they are all quite different with varying colors and patterns, they’re probably log-grown. If they all have a similar conical shape, are pale and have little to no marking, they’re probably block-grown.
The Stems and The Gills
Log-grown mushrooms will always have short stems and the gills (on the bottom of the mushroom) will be pure white and unbroken. Block-grown mushrooms may have bulbous stems or broken or discolored gills.
If the mushrooms have any kind of smell (besides mushroom-smell) like ammonia they are most likely low-quality block-grown specimens.
To learn more about the health benefits of log-grown shiitake mushrooms, visit our Nutrition page.