The mushroom cultivator. A practical guide to growing mushrooms at home

Paul Stamets. The mushroom cultivator. A practical guide to growing mushrooms at home. - Agarikon press, 1983

: [url=http://txt.drevle.com/text/stamets-mushroom_cultivator-a_practical_guide-1983/58]Paul Stamets. The mushroom cultivator. A practical guide to growing mushrooms at home. - Agarikon press, 1983[/url]
 

Содержание

FOREWORD by Dr. Andrew Weil

PREFACE

I. INTRODUCTION TO MUSHROOM CULTURE

II. STERILE TECHNIQUE AND AGAR CULTURE

III. GRAIN CULTURE

IV. THE MUSHROOM GROWING ROOM

V. COMPOST PREPARATION

VI. NON-COMPOSTED SUBSTRATES

VII. SPAWNING AND SPAWN RUNNING IN BULK SUBSTRATES

VIII. THE CASING LAYER

IX. STRATEGIES FOR MUSHROOM FORMATION (PINHEAD INITIATION)

X. ENVIRONMENTAL FACTORS: SUSTAINING THE MUSHROOM CROP

XL GROWING PARAMETERS FOR VARIOUS MUSHROOM SPECIES

XII. CULTIVATION PROBLEMS AND THEIR SOLUTIONS: A TROUBLESHOOTING GUIDE

XIII. THE CONTAMINANTS OF MUSHROOM CULTURE: IDENTIFICATION AND CONTROL

XIV. THE PESTS OF MUSHROOM CULTURE

XV. MUSHROOM GENETICS

APPENDICES

GLOSSARY

BIBLIOGRAPHY

INDEX

PHOTOGRAPHY AND ILLUSTRATION CREDITS

ACKNOWLEDGEMENTS

OCR
44/The Mushroom Cultivator
more than a million cells in less than ten hours. In another ten hours, each one of these bacteria
beget another million cells. If only a small fraction of one percent of these contaminants survive the
sterilization process, they can render grain spawn useless within only a few days.
Most microorganisms are killed in the sterilization process. For liquids, the standard time and
pressure for steam sterilization is 25 minutes at 1 5 psi (250 F). For solids such as rye, the sterilization time must be increased to insure that the steam sufficiently penetrates the small air pockets
and structural cavities in the grain. Within these cavities bacteria and other thermo-resistant organisms, partially protected from the effects of steam, have a better chance of enduring a shorter sterilization period than a longer one. Hence, a full hour at 15 psi is the minimum time recommended to
sterilize jars of rye grain.
Some shipments of grain contain extraordinarily high levels of bacteria and fungi. Correspond-

ingly the contamination rate on these grains are higher, even after autoclaving and prior to
inoculation. Such grain should be discarded outright and replaced with grain of known quality.
Once the grain has been sterilized, it is presumed all competitors have been neutralized. The
next most probable source of contamination is the air immediately surrounding the jars. As hot jars
cool, they suck in air along with airborne contaminants. If the external spore load is excessively
high, many of these contaminants will be introduced into the grain even before conducting a single
inoculation! In an average room, there are 10,000 particulates exceeding .3 microns (dust, spores,
etc.) per cubic foot while in a "sterile" laboratory there are less than 1 00 per cubic foot. With these
facts in mind, two procedures will lessen the chance of contamination after the spawn jars have been
autoclaved.
1.

If autoclaving grain media outside the laboratory in an unsterile environment (a kitchen, for
instance), be sure to clean the outside of the pressure cooker before bringing it into the
sterile inoculating room.

2. Inoculate the jars as soon as they have cooled to room temperature. Although many

cultivators leave uninoculated jars sitting in pressure cookers overnight, this is not recommended.

The amount of water added to the grain is an important factor contributing to the reproduction
of contaminants. Excessive water in a spawn jar favors the growth of bacteria and other competitors.

In wet grain the mushroom mycelium grows denser and slower. Oversaturated grain kernels
explode during the sterilization process, and with their interiors exposed, the grain is even more
susceptible to contamination. In addition, wet grain permeated with mycelium is difficult to break up
into individual kernels. When such grain comes in contact with a non-sterile medium such as casing
soil or compost, it frequently becomes contaminated. Spawn made with a balanced moisture
content has none of these problems. It easily breaks apart into individual mycelium covered kernels,

insuring a maximum number of inoculation points from which mycelial strands can emerge.
Determining the exact moisture content of grain is not difficult. Once done, the cultivator can
easily calculate a specific moisture content that is optimal for use as spawn. Commercial rye grain,
available through co-ops and feed companies, is 11 % water by mass, plus or minus 2%. The precise amount of water locked up in grain can be determined by weighing a sample of 100 grams.

PDF compression, OCR, web-optimization with CVISION's PdfCompressor