When to Harvest Reishi Mushroom
Answered by: Bill Chalmers
Question from: Kim Johnson
Posted on: August 20, 2007

I have a reishi mushroom kit. The mushroom is conch form and about 25 cm across and maybe 10 cm wide. Do I harvest it now? I don’t know really how long to let it grow. Can it get over-ripe.... maybe I already let it go too long. Also, what’s the best way to dry it and/or to make it into a tincture (do i dry it first or make it with the fresh mushroom)?

Local environmental conditions as much as anything else will determine when to harvest the reishi. Ideal growth conditions include temperature ~80-90F, humidity ~70-80%, and subdued light. Under ideal conditions the conch might reach 12" in diameter and the block might produce several conches at once. A sign that a conch has reached "maturity" and may not grow any larger would be the production of reddish-brown spores which appear as dust near and around the block. I suggest harvesting the conches when spores show up or when the seasonal weather starts to change away from warmth and humidity since gowth will slow down/cease for the year anyway. Making tinctures is a technical subject that most people misunderstand. In general the polysacharides will not be soluble in alcohol and the triterpenes will not be soluble in water, so alcohol/water mixes are not very good solvents for either type of compound. The popularity of liquor (alcohol/water) extracts is founded on the availability of liquors such as vodka and the fact that such extracts are preserved against microbial growth. The best situation would be to dry the conches and then extract with pure dry alcohol, then to extract the residue with water. In this case however the water extract will be very susceptible to growth of bacteria and molds. An option would be to freeze it (make ice cubes). A freeze dryer would convert it into a stable, dry (although possibly somewhat hygroscopic) powder.

[Bill Chalmers is a mushroom expert who kindly agreed to answer this question. -Ed.]

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