Cote in Culture

Growing Oyster mushrooms in columns gives rise to natural-looking fruitbodies. Having evolved on the vertical surfaces of hardwood trees, Oyster mushrooms with their off-centered stems, grow out horizontally it first, turn, and grow upright at maturity. * TO often results in the formation of highly desirable clusters, or "bouquets," of Oyster mushrooms. The advantages of cropping clusters from columns are that many young mushrooms form from a common site, al owing 1/4 to 1 lb. clusters to be picked wit! SO further need for trimming, yields of succulent young mushrooms are maximized while spore load is minimized, harvesting is far faster than picking mushrooms individually, and the clusters store far better under refrigeration than

* This response-to grow against gravity-is called "negative geotropism" See Badham (1985)

I igure 165. Bag culture of the Button mushroom (.Agaricui: brunnescens).

Mushroom Paterizer
Figure 167. Bouquets of Golden Oyster mus'trooms (.Pleurotus citrinopileatus) fruiting from columns of pasteurized-wheat straw.

individual mushrooms

Automated column-pacicng machines have been developed and tested <n North America and Europe wi h varied results. Typically the machines rely on an auger or "Archimedes screw" which forces the straw through a cylinder with considerable force. Straw can be pasteurized, cooled, and inoculated along a single production line. Columns are packed, usually horizontally, in a sleeve which can be removed for the vertical placement of the column in the growing room. Several :nventive eng'neers-turned-mushroom growers are currently developing production systems based on this concept. For many, separating each activity— pasteurization, inoculation, filling, and

** Readers should be note that many suppliers sell ducting in "lay-flat" diameter, which is actually 1/2 of circumference. Simply divide the "lay-flat" mea surement by 1.6 for true, inflated diameter positioning—simplifies the process and pre vents cross-contamination

Vertical cylinders can be made of a variety ol materials.The least expensive is the flexible polyethylene ducting designed for air distribution in greenhouses. a\ ailable in rolls as long as 5000 ft. and in dirmeters from 6 - 24 inches. ** Drah-field ^.'pe, polycarbonate columns, and similar"hard" column materials have also been employed with varying degrees of success. More extravagant systems utilize inner-rotating, perforated, hard columns equipped with centrally located air or water capillaries which double as support frames but I have yet to see such a system perfected. Many farms even use overhead trolleys for ferrying the columns into and out of the growing rooms (Seewigure 148). Of the many variations of Column Culture, the ease and inexpensiveness of the flexible polv

Cross Section Mushroom Column
Figure 168. Cross section of 15 inch diameter column of Oyster mushroom mycelium contaminated with an anaerobic core
Mushroom Culture Polyethylene Plastic

Figure 170. As the subrtrate fills the column, spawn is added and the plastic elongates.

Figure 169. Inoculating columns- First, plastic cutting is cut to length and secured to the stainless steel funnel. (I had a spring-activated collar custom-made ft - this purpose.) A knot is tied several inches off the ground.

ethylene tubing has yet to be surpassed.

Some growers strip the columns after colonization to expose the greatest surface area.The columns are held together with two to four vertically running lengths of tw:ne. Although the inter „on is to maximize yield, the massive loss oi moisture, combined with the die-back of exposed mycelium, can cancel any advantage contemp ated. El-Kattan (1991) and others who have conducted extensive studies have found the accumulation of carbon dioxide during colonization has an enhancing effect on subsequent yields. Studies prove the partially perforated plastic gives rise to larger fruitings of Oyster mushrooms sooner than substrates fully exposed. Exposed columns not only lose more moisture, but they also allow the sudden escape of carbon dioxide, resulting in a substan tial reduction of the total mass of the substrate Controlling the loss of carbon dioxide has a beneficial impact on overall yield. Zadrazil (1976) showed that fully 50% of the mass of wheat straw evolves into gaseous carbon dioxide during the course of Oyster mushroom production. (See Figure 39.)

Another factor in choosing a type of column culture is greatly determined by the mushroom strain. Strains of Oyster mushrooms which p reduce clusters of many mushrooms, and' vhich are site-specific to the perforations, work better in the perforated column model than in the fully exposed one Mushroom strains which produce only one, two or three mushrooms per c luster—as with some Pleurotus pulmonarius cultures—do not demonstrate an obvious advantage with the perforated column method. Hence, the benefits of perforated column can be easily overlooked unless you test many Oyster

Figure 170. As the subrtrate fills the column, spawn is added and the plastic elongates.

Mushroom Culture Polyethylene Plastic

Figure 172 & 173. Once filled, the collar is released and the plastic is tied into a knot

Figure 171. by slair.miiig the column to the floor during filling, the straw packs densely.

Figure 172 & 173. Once filled, the collar is released and the plastic is tied into a knot mushroom strains.

From extensive trials, I have determined functional limits in the cultivation of Oyster mushrooms in columns Columns less than 8 inches give meager fruitings and dry out quickly. Columns whose diameter exceeds 14 inches are iii danger of becoming anaerobic at the core. Anaerobic cores create sites of contamination which emanate outwards, often overwhelming the outer layer of mycelium. (SeeFigurel68. )

Columns are best filled w.ji bulk, pasteurized substrates (such as straw) via conveyors leading to a stainless steel funnel. If conveyors are unavailable, then the pasteurized straw can be moved from the steam room (Phase II box) to a smooth table top via a pitch-fork. Either on the conveyor or on the table top, grain spawr ij» evenly distributed. The inoculated substrate is then directed to the recessed funnel. The funnel should be positioned 10-14 ft. above the

Figure 171. by slair.miiig the column to the floor during filling, the straw packs densely.

Medicinal Mushrooms Chart

figure 174. Once ferried into the growing room, u.c -ofumn is inverted so that the loose straw at .e too is compressed. Stainless steel arro- ^d heads mounted on a board are use', to puncture 200- JO h es in each plastic column. Note thi t 75% of the weight of the column is floor-supported.

figure 175. The seme column as portrayeu m ri . ures 135-140, 12 days later after feneration with grain spawn of the Pink Oyster mushroom (Pleurotus djamor). 27 lbs. of fresh mushrooms were harvested on the first flush figure 174. Once ferried into the growing room, u.c -ofumn is inverted so that the loose straw at .e too is compressed. Stainless steel arro- ^d heads mounted on a board are use', to puncture 200- JO h es in each plastic column. Note thi t 75% of the weight of the column is floor-supported.

floor. Plastic ducting is pre-cut into 12 ft. lengths and tied into a tight knot at one end.' ie open end of the plastic tube is pulled over the cylindrical down-spout of the funnel and secured with "bungee cords" or, preferably, a spring-activated, locking collar

Si ce the tensile strength of a 12 in. diameter, 4 mil. thick, polyethylene tube is insufficient tc suspend the mass of moist straw tightly packed into an 8 ft. long column, care must be taken in filling. After securing the empty plastic column 4-6 inches above the floor, the plastic column slowly elongates with substrate filling. rVhen a few air-release holes are punched near the bc( torn of the column, air escapes during filling, facilitating loading. Most importantly, ca" l-ties—air pockets—must be eliminated. As the figure 175. The seme column as portrayeu m ri . ures 135-140, 12 days later after feneration with grain spawn of the Pink Oyster mushroom (Pleurotus djamor). 27 lbs. of fresh mushrooms were harvested on the first flush column is filled, the poly-tubing stretches until partially supported by the fl«r. As the column fills with substrate, a worker hugs the column, gently lifts it several inches of he floor, anc forcibly slams it downwards. (See Figure 171). The impact against the floor increases substrate density and eliminates cavities.This ritualis repeated until the column is filled to a height of approximately 10 feet.

Once the column has been filled to capacity, the securing collar is removed by i person standing on a small step ladder. The column is tied off at the top using whatever means deemed most efficient (a twist-tie, knot, collar, etc. ). The column is carefully taken away from the inoculation station and another tube is immediately secured for the next fill of inocu lated substrate. An 8-ft. long column, 12 inches in diameter, tightly packed can weigh 120-150 lbs. depending upon moisture content, density (determined largely by particle or"chop" size), and spawn rate.

After the top folds of the column have been secured, the column should be inverted, upside down .The loosely packed substrate that waa in the top 2 feet of the column is now at the bottom and the dense substrate at the bottom of the column is now switched to the top This, in effect, packs the column t:ghtly. If the straw is not tightly pressed against the plastic, cauring substantial cavities, mushrooms form behind the plastic and develop abnormally. In contrast, tight fills cause the substrate and plastic to be forcibly in contact w!th one another. When an arrowhead puncture is made, the plastic bursts. The mycelium is exposed to the growing room's oxygen :ch, humidified atmosphere. Given proper lighting and temperature conditions, a population of primordia form specific to each puncture site. Growers using this technique develop a particular fondness for strains whLh are site-specific to the punctures in their response to standard initiation strategies.

Once the column is removed from the inocu-lah:on station, two people carry or trolley it to the growing room, where it is hung and allowed to :ncubate. Overhead trolley systems similar to those employed in slaughter houses, cold storage rooms, even clothes dry-cleaner com par ;s can be adapted for this purpose. If the columns are carried, care must be taken so that the columns do not sag in the middle, lest they break. Modified hand-trucks fitted with a slant board are helpful in this regard.

The columns are hung to approximately 4 hches above the floor. After hanging, they noticeably stretch with: n a few seconds to become substantially floor supported. Columns (10

Hypsizygus Tessulatus

Figure 176. Bottle culture of a dark gray strain of Hypsizygus tessulatus, known in Japan as Buna-shimeji or Yamabikc Hon-shimeji- This mushroom is currently being marketed in America as just "Shimeji". The Japanese prefer to use the Latin name Hypsizygus marmoreus for this mushroom. For more information, please consult Chapter 21.

Figure 176. Bottle culture of a dark gray strain of Hypsizygus tessulatus, known in Japan as Buna-shimeji or Yamabikc Hon-shimeji- This mushroom is currently being marketed in America as just "Shimeji". The Japanese prefer to use the Latin name Hypsizygus marmoreus for this mushroom. For more information, please consult Chapter 21.

inches in di -meter and greater) suspended in the air after inoculation will probably fall before the cropping cycle is completed.

Directly after the columns have settled to the floor, within 1 hour, numerous holes must be punched for aeration. If holes are not punched until the next day, substantial loss of spawn viability occurs, and a bacterial bloom ensues in the stagnant, air-deprived column. However, if the column is suspended and holes are punched too soon, the punctures elongate and the column soon is in danger of splitting apart. For an 8 ft. high column, 12 inches in diameter, at least 200 and no more than 400 1/8 in. holes should be punched for maximum yield. Stainless steel, four bladed arrowheads, mounted on a board are recommended for this

Prescription Bottle Magic Mushrooms

Figure 177. Bottle culture of a Magic Mushroom known as Psilocybe cubensis.

Figure 178. Sterilized sawdust inoculated vi? top-spawning.

Bottle culture is an effective means for growing a vanety of gourmet and medicinal mushrooms on sterilized substrates. However, bottle culture is impractical for the cultivation of mushrooms on pasteurized bulk substrates such as straw or compost. San Antonio (1971) first published a method for growing Agaricus brunnescens, the Button mushroom, on cased, sterilized grain from bottles. This article be-

Figure 178. Sterilized sawdust inoculated vi? top-spawning.

Figure 177. Bottle culture of a Magic Mushroom known as Psilocybe cubensis.

purpose. (See Figure 174). Although the punc-ure hole is only 1/8 inch in diameter, four slits 1-2 inches in length are also made. These flaps open as the mushrooms push through.

Mycelium Culturing Template
Figure 179. Downwardly growing mycelium a week after inoculation into sterilized sawdust

came a template for the cultivation of many other mushrooms. A counter-culture book on psilocybian mushroom cultivation by Oss & Oeric (1976) (a. k. a. Dennis & Terence McKenna) brought the concept of bottle culture to the forefront of small-scale mushroom cultivators in America. Currently, Asian growers have adapted bottle culture, originally designed for the easy cropping of Enoki mushrooms (Flammulina velutipes), to the cultivation of many other gourmet and medicinal mushrooms, including Buna-shimeji (.Hypsizygus tessulatus), Reishi (Ganoderma lucidum), Woo d Ears (Auricu lar ia po lytricha), and some variet s of Oyster mushrooms.

The advantage of bottle culture is that the process can be highly compartmentalized and easily incorporated into the many high speed production systems adapted from other industries. The disadvantage of bottle culture -s that sawdust substrates must be top-spawned and grain spawn can not be eas'ly mixed through bottles containing sawdust. The bottles are filled to within 2 inches of the brim with moistened supplemented sawdust and then sterilized for 2-4 hours at 15-20 psi. (The formuk is the same for bag culture of Sh' 'take and Enok:take. Please refer to Chapter 17 )When gram spawn is added at inoculation, and the bottles are shaken, the spawn descends to a depth of only a few inches. Hence, the mycelium quickly covers the top surface layer and then grows slowly downwards into the sterilized sawdust. This results in imbalanced time frames in terms of the age of the myce [urn at the top vs. the bottom of the bottle. The newly growing mycelium near the bottom inhibits the formation of mushrooms in the top layer of mydflium. The discrepancy in age inhibits maximum mushroom formation from the total surface area of the substrate. When the mycelium is actively growing out, the total mycelial colony can not

easily shift from colonization to primordia formation.

An advantage of this method is that mushrooms, when they do form, arise from the r DSt mature mycelium, at the top of the bottles Side and bottom fruitings are rare. If the cultivator can afford to make the initial investment c incubating thousands of bottles until the first cycle starts then the drawbacks are primarily that of lost time and delay in the initial production cycle, but not overall yield. Top-spav< ing is fast and convenient for bottle and small bag culture, although I see more benefits from through-spawning Many cultivators in Japan accelerate the colonization process inoculating the Dottles with pressurized liquid spawn.

With the natural evolution of techniques. Asian cultivators have replaced bot ies with similarly shaped, cylindrical bags.Th".. h bnd method is preferred by many growers in Thailand, Taiwan and Japan.

Liquid inoculation of sterilized, supplemented sawdust allows for inoculation methods resembling the high production system* seen il i a soda pc 5 factory With re-en;/neering such high speec' assembly line machinery could be retrofitted for commencal bottle and bag cultivation. Unless an aggregate-slurry is usee., liquid spawn settles near to the bottom of the bottler. (For a complete discussion of liquid fer mentation and inoculation techniques, please refer to Chapter 15). Bottles can be in lged horizontally in walls or fruited vertically. In Ja pan, bottle culture is the method preferred by many cultivators in the growhg of Yamabiko Hon-shimeji or Buna-shimeji (Hyps' >,us tessulatus varieties), Shlrotamogi ke (Hyp-sizygus ulmarius), Enokitake CFlarnmhnft velutipes) and Reishi (Gcnoderma lucidum).

Bottles of various sizes can be used. e most common are between 1 quart (1 liter) and 1 gallon (4 liters). The openings are usually between 50-100 mm. in diameter. Glass bottles are not as popular as those made om polypropylene-like materials. Each bottle is fitt- d with foiled cotton or an autoclavable Ud equipped with a microporous filter disc After full colonization, the lids are remold, and the surface mycelium is exposed to the growing room environment. Enoki growers often insert a coil of paper or clear plastic to encourage stem elongation.

Agaricus Mushroom Drug

ton Mushroom Agaricus v.------------- ----- ~ „_,_«.

P .. #953006987.1) T»e cavities allow transpiration and prevent anaerobic core ton Mushroom Agaricus v.------------- ----- ~ „_,_«.

P .. #953006987.1) T»e cavities allow transpiration and prevent anaerobic core

___cropping containers 207

tmcs—---—J-l.^-" - ■ ~ ■ KiasaaaMgaME ^aamssassxssasi zsa3 ■■ -------...zs,-.^.——BBma ^

___cropping containers 207

tmcs—---—J-l.^-" - ■ ~ ■ KiasaaaMgaME ^aamssassxssasi zsa3 ■■ -------...zs,-.^.——BBma ^

Pleurotus Ostreatus Fruiting Mushroom
Figures 182 and 183. Oyster mushrooms (Pleurotus ostreatus) fruiting from suspended, perforated, plastic containers. A group of innovative Russian cultivators are refining this method
Mushroom Casing LayerBedding For Mushrooms Peat Moss
Fi' es 184 and 185. Applying a peat moss casing.


Ilutton growers long ago discovered that, by placing a ' layer of peat moss over compost grown through with mushroom mycelium, yields were greatly enhanced. The casing served several functions. Foremost, the casing layer acted as a moisture bank ! where water reserves could be replenished through the course of each crop. The casing layer also limits damage to the mycelium from fluctuations in relative humidity. Besides moisture, the casing provides stimulatory micro-organisms, essential salts and minerals. These combined properties make casing a perfect environment for the formation i and development of primordia.

In the cultivation of gourmet and medicinal mushrooms, casing j soils have limited applications. Cultivators should be forewarned that ! green-mold contamination often occurs with soil-based casing layers, especially when air circulation is poor and coupled with contact with wood. The possible benefits of cas; lg are often outweighed by j the risks they pose. Few saprophytic gourmet species are absolutely j dependent upon casing soils, with the exception of the King Stropharia, (Stropharia rugoso-annulata).

A dozen or so casing soils have been used successfully in the commercial cultivation of mushrooms. They all revolve around a central sf t of components: peatmoss, vermiculite, calcium carbonate (chalk), and calcium sulfate (gypsum). Recently, "water cryst .Is " a water-capturing plastic, have been tried as a casing component with varying results.Thei crystals can absorb up to 400 times their weight in water and do not support contaminants, two Highly desirable characteristics. Unfortunately, the fact that water crystals are not fully biodegradable and can not be easily recovered from the spent substrate greatly limits their acceptance by environmentally astute growers. Starch-based water absorbants tend to clump and must be added with an aggregate. Cultivators must weigh in balance these factors when designing the casing mixture.

For many years, cultivators have used the following casing formula.

Casing Formula (by volume)

10 units peat moss

1 unit calcium sulfate (gypsum)

1 unit calcium carbonate (chalk)

Calcium carbonate is used to offset the acidity of the peat moss and should be adjusted according to desired pH levels. Calcium sulfate, a non-pH affecting salt*, provides looseness (particle separation), and mineral salts, especially sulphur and calcium, essential elements for mushroom metabolism. Peat moss, although lacking in nutrition, is resplendent with mushroom stimulating Bacteria and yeasts.The above-described formula depends greatly on the starting pH of the peat moss. Generally, the pH of the resultant mixture is 7.5-8.5 after make-up. As the mushroom mycelium colonizes the casing layer, pH gradually falls. For some acid-loving species mentioned in this book calcium carbonate should be excluded. Typically, this chalk-free mixture gives pH readings from 5.5-6.5.

Mix the dry components together in a clean bucket or wheel barrow. Add water slowly and evenly. When water can be squeezed out to form brief rivulets, then proper moisture has probably been achieved. A 75% moisture content is ideal and can be tested by measuring the moisture lost from a sample dried in a hot oven.

Once wetted, the casing is applied to the top of a substrate, but only after it has been thoroughly colonized with mycelium. Casing soils are best used with tray, bag, or outdoor mound culture. Although some of the following mushroom species are not absolutely dependent upon a casing soil, many benefit from it.Those s jcies marked with an"*" are dependent upon s -il microorganisms for fruitbody formation. Under sterile conditions, the "*" species will not fruit well, or at all. Typically, a one-inch layer of casing soil is a placed onto 4-10 inches of myceliated substrate.

Agaricus brunnescens* The Button Mushroom

Agaricusbitorquis* The Warm Weather Button Mushroom Agrocybeaegerita. The Black Poplar

Mushroom Coprinus comatus The Shaggy Mane Ganoderma lucidum, Reishi or Ling Chi

* Gypsum, calcium sulfate, may affect pH by 1/2 of a point Its pH-altering ability is minor until the sulphur evolves into sulfuric acid. Calcium and sulphur are essential elements in mushroom metabolic processes If the substrate is lacking m these essential elements, yields are adversely affected. Shiitake, in particular, benefits from the addition of calcium sulfate to sawdust substrates.


The parameters outlined here are based on the author's experi- | ences over many years of cultivation. Each mushroom species j thrives on a limited range of substrates. However, strains within a ; species are even more specific in their habitat requirements, tem- j perature preferences, and their flushing intervals. Wherever possible, I have identified individual strains so that readers can achieve similar ' yields. These strains are being kept in perpetuity in the Stamets Cul- ;

ture Collection. Some strains are proprietary and can be obtained by ! contacting the author through his business Funigi Perfect!. Most spe- ; cies can be obtained from a number of culture libraries such as the American Type Culture Collection. These sources are listed in the Resource section in Appendix IV.

To remain competitive, cultivators must continuously search out j I and develop new strains from wild stocks. Although specific tem | perature parameters are outlined in this section, some strains will ; perform better outside of these prescribed limits. In general, rapid cycling strains prefer higher temperatures. The cold weather strains require a longer gestation period before fruiting. The cultivator must customize initiation strategies to each strain, a process fine-tuned with experience.

For instance, I isolated a strain of the Winter Mushroom or Enokitake, Flammuhna velutipes, from the high-altitude forests outside ofTelluride, Colorado in 1990. Typically, strains of this mushroom produce at temperatures around 45-55° F. (7-13° C.). This isolate produces prolifically between 65-75° F. (1824° C.), outside of any published parameters for this' mushroom. In this case, the classic initiation strategy of cold-shocking is unnecessary. If you are a commercial cultivator ot Enoki mushrooms, spending thousands of dollars a year on refrigeration systems, this unique strain has exceptional monetary value.

Of the many factors already described for producing successful crops, the mis-application of only one can result in poor fruitings or absolute failure. Each grower is stroi^Jy encouraged to conduct mini-trhj^mefore endeavoring commercial culti > ^J

Optimization of yields is reM'frgnly it the grower becomes keenly sensitive to, and satisfies the unique needs of, each mushroom strain. Therefore, the following parameters should be used as a general guide, to be refined in time and with experience. The first set of parameters is centered on the incubation period, cailed SPAWN RUN; the second set is for initiating mushrooms, called PRIMORDIA FORMATION and the third is for cropping or FRUITBODY DEVELOPMENT. In essence., each stage of mushroom growth has a different ideal environment. As each factor is changed, sec; ondary effects are seen. The skill of a mushroom cultivator is measured by the ability to compensate for fluctuations in this complex mosaic of variables.

compensate for fluctuations in this complex mosaic of variables.

Spawn run spans the period of time when the mycelium is colonizing the substrate. Other than the factors described below, the amount of spawn inoculated into the substrate can greatly affect the duration of colonization, and therefore, the time to fruiting.

Moisture: Substrate moisture contents should be between 60 and 75%. Moisture contents below 40% promote slow, wispy mycelial growth. Unless a casing layer is used, the moisture content of the substrate gradually declines from initial inoculation. For instance, the water content of straw at inoculation is nearly 75%, precipitously dropping after the first flush to the 60% range, and continuing to steadily decline through the remainder of the cropping cycle. The cultivator's prime responsibility during this period is to manage the moisture reservoir as if it were a bank. Moisture loss must be limited before initiation or else the mycelium will fail in its efforts to generate mushrooms, which are themselves about 90% water. The solution: retard the loss of substn te moisture by maintaining high humidity during spawn run.

Air Exchange Mushroom mycelium is remarkable for its tolerance for carbon dioxide. At levels snuffing out the life of a human, mycelium thrives. Some Oyster mushrooms' growth rates peak at 20% carbon dioxide, or 200,000 ppm. However, this C02 environment is equally stimulatory to competitor molds. The best level varies with the strain, and whether one is working with pasteurized or sterilized substrates.

To reduce carbon dioxide, fresh outside air

Figure 188. The Button must_room (Agaricus brunnesttns) fruiting from cased grain.

is introduced. Consequently, several other phenomena occur: evaporation is increased, humidity drops, temperature changes, and the net number of contaminant part::les entering the growing room ises as ?':: exchanges are '..lcreased.

Temperature: As a general rale, incubation temperature runs higher than the temperature for primordia formation, internal temperatures should not exceed 95° F. (35° C.) or black pin molds and other thermophilic competitors wiD awaken, especially under the rich C02 conditions created as a by-product of spawn running

Lighting: For the species described in this book moderate lighting has no effect, adverse or advantageous, on the mycelium daring spawn ran. Bright, unfiltered, direct sunlight is damaging. Light is especially harmful when intensities exceed 10,000 lux. From my experiences, the mycelhl mat only becomes photosensitive after it has achieved a threshold critical mass, usually coincident with full colonization, and after carbon dioxide evolution has steeply declined.

Continue reading here: The Initiation Strategy

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