Auto-SummaryThis post is an excerpt from a Mushroom Cultivation FAQ discussing casing, a method used in growing mushrooms. Key points include:
1. Casing is the process of covering colonized substrate with a non-nutritive layer (vermiculite, coir, 50/50 mix, etc.) to protect it from drying out, provide a humid microclimate, serve as a water reservoir, and support growth of fructification-enhancing microorganisms.
2. The four purposes of casing are to protect from drying out, provide a humid microclimate, supply water, and support fruiting microorganisms.
3. Casings can be better than cakes as they produce larger flushes, help understand the mushroom life cycle, and act as a stepping stone to more sophisticated methods.
4. To crumble substrate, pull apart PF cakes or use a ziploc bag to minimize contamination.
5. Common casing layer ingredients include peat, vermiculite, limestone, hydrated lime, oyster shells, coco coir, and peat-based potting soil.
6. Prepare the casing layer by mixing ingredients, adding water until it retains a few drops when squeezed, and pasteurizing or sterilizing to avoid contamination.
7. Apply the casing layer evenly over the substrate
The following is an excerpt of not yet finished Mushroom Cultivation FAQ:
What are some (essential) links I should take a look at when I have a question about casing?
Please refer to the following 3 links for reference to casing, as well as links
listed At the begining of this document. Almost ALL
questions regarding casing, its purpose, and et cetera can be found in the links
and here as well. Casing has more scientific knowledge and write-ups than cakes
do (since casing is a popular way by which edible/medicinal mushrooms are grown),
and this technical, widely-published information should be examined closely before
posting any questions regarding casings.
TMC
Chapter VIII: The Casing Layer
50/50
Casing Tek
What's
the Matter With My Casing?
These links will serve as an appropriate reference to the questions and answers posed below.
The term "casing" as it is used here and within the OMC (online mushroom community) is the method by which substrate (either PF style jars or colonized grain) is crumbled into smaller pieces, and covered with a non-nutritive layer such as vermiculite, coir, 50/50+, etc.
How do I case?
Casing is a simple process. You simply crumble your substrate, layer it in an appropriate container, and cover with your casing layer. A Detailed "Casing for Dummies" writeup goes over each step of the casing process with pictures.
Why case? Why not?
The casing layer serves 4 purposes:
1.) To protect the colonized substrate from drying out.
2.) To provide a humid microclimate for primordia formation and development.
3.) To provide a water reservoir for the maturing mushrooms.
4.) To support the growth of fructification enhancing microorganisms.
(TMC, p 128-129)
The 1st (main) 3 elements all are ancillary manifestations to the substrate's requirement for water. Mushrooms are 90% water, and casing not only provides water, but seals it in and actually helps make the casing produce moisture on its own. Casing has gained a reputation for being "hard" for beginners, unfortunately. It is actually just one more step after the birth of the PF jars- the "crumble and case" step.
Newbies fear casing for a few reasons, none of which are flippant:
1.) Casings add another vector of possible contamination (several within the steps) as compared to PF and cakes.
2.) Casings require additional steps, which are not necessary to produce fruit.
3.) Casings put "all of your eggs in one basket"- casing containers often contain anywhere from 1 to 6 PF style cakes. If one casing is lost, the equivalent in PF cakes (and their productivity) is lost.
4.) Casings require more attention to the rh (relative humidity) than cakes do.
Casings require alternating humidity levels, 95 -100% at the pinning stage, and
around 90% at the fruiting stage, while cakes can remain and produce well at a
stable 95% rh.
Casings can be better than straight cakes because:
1.) They produce larger flushes, both in terms of the size, weight, and gross/net harvest.
2.) They give the hobbiest a better understanding of the mushroom life cycle. Not only for psilocybes, but learning the basic life cycle can introduce the new hobbiest into the world of gourmet and edible mushrooms.
3.) Casings are often a "stepping-stone" into further, more discreet and sophisticated methods of mushroom production.
What does "crumble and case" mean?
The term "crumble and case" is just that- crumbling the substrate into smaller, more manageable pieces, and casing the pieces by laying a casing layer over the crumbled substrate.
How should I crumble the substrate?
There are several ways, all of which are similar. Birth the cake, and simply pull it apart with CLEAN hands. PF cakes feel soft and gummy/styrafoam-ish, so you really will need to *pull* them apart if they are adequately colonized. The more a cake is colonized, the more effort is required to pull it apart (up to a point). You can also birth the cake into a large ziploc bag, and pull it apart thru the plastic- which eliminates the amount of handling required (and therefore reduces the possibility of contamination as well). When casing, you will need to remove any primordia (pinheads, tiny mushrooms) that have started to grow on the cake. If these are left on, they will rot inside the crumbled casing, creating a new vector for contamination within the substrate layer of the casing.
What different casing layer ingredients are there?
Peat:
Main ingrediant of many casing formulations, it´s pH is under 7(acidic),
has to be buffered with limestone
Vermiculite:
Ingredient of the popular 50/50+ casing mix, can also be used as the solely
casing ingredient. The drawback of using pur vermiculite is that it´s
hard to tell the moisture of the casing by solely looking at it´s surface,
since the vermiculite stays more or less the same color despite it´s saturation
level. Other materials, like peat or coco coir have a lighter color when dry.
Peat based potting soil: Can be used intead of peat, in this case on can use
less limestone, since the pH of the soil is already around 5-6 compared to the
pH of peat which is around 4.
Coco coir:
It has very good water retaining materials and can be used as a casing material
either solely or in mix with peat and/or vermiculite.
Limestone(CaCO3, chalk(NOT blackboard chalk!):
Acts as a buffer agent in the casing formulation, rises the pH. Depending on
the initial pH of the casing mix, 10-20 vol% should be used.
Hydrated lime:
Also rises the pH but it´s a much stronger base than limestone, therefore
it should be used only in about 1/3rd of the amount compared to limestone. Generaly
limestone is prefered to hydrated lime. ATTENTION: Hydrated lime can cause severe
burns on skin, even blindness, if it comes in contact with eyes, so be very
carefull when handling it.
Crushed oyster shells:
Consists mainly of CaCO3, the structure is much coarser than grinded limestone
therefore the imediate effect on the pH is not so strong. But it acts as a longtime
buffer along with limestone, so it´s a good idea to substitute a part
of limestone with crushed oyster shells.
How should I prepare the casing layer (sterilize,
pasteurize, what?)
The casing ingredients should be mixed in a bowl, then the water should be
added. The correct water amount is reached, when you take a handfull of the
casing mix and squeeze it in your hand ,not too hard, a few drops of water should
come out of it. That´s the correct moisture.
Some mushroom species need microorganisams in the casing layer that help initiate
pinning, P. cubensis is NOT among them. So there is no reason not to sterilize
or pasteurize the casing.
A pasteurisation can be achived by filling the moist material into a suitable
microwave container with a cover and microwaved for 10 minutes at high and stirring
it a few times during the microwaving to achive an uniform heat distribution.
A sterilisation can be done in a pressure cooker by filling the substrate into
autoclavanle bags or jars and pressure cooking it for 1 hour.
Contrary to popular belief P. cubensis doesn´t need misrooorganisms in
the casing for the mycelium to pin, so sterilisation can be used where contamination
problems are a problem.
After the casing material has cooled down to room temperature it can be applied.
How and how deep should I apply the casing layer?
Fill the colonized substrate in a casing container, even with a clean spoon or
fork and spoons the casing material on the top of it, without pressing it down.
The depth of the casing should match the depth of the substrate and should be
around 1/4 of the substrate depth.
Should I use a bottom casing layer?
There is a very popular debate in the OMC (online mushroom community) about whether or not to add a bottom casing layer to a casing (usually a vermiculite or sometimes coir layer, notwithstanding what you used to case the top layer with). TMC refers to a bottom casing layer only once: "As an option, a layer of partially moistened vermiculite can be placed along the bottom of the tray to absorb excess water. (TMC p 134, Emphasis added). Some of the arguments for each are as follows:
No bottom casing layer:
1.) Bottom casing layers can harbor contamination that is difficult to see and detect until too late. (This is the major argument against bottom casing layers).
2.) It is superfluous and also adds more hassle than its worth. Casings fruit as well without them and are extra work.
3.) A bottom casing layer takes up too much additional room for not enough return. Space within a casing container is at a premium (since the thicker the casing layer=the larger the flushes), and it is wasted with the addition of the bottom layer.
Bottom casing layer:
1.) The bottom casing layer acts as an additional reservoir of water from which the substrate can be supported (as well as the top layer). Since mushrooms are 90% water, the more additional moisture (up to a point where it does not soak the substrate) will produce heartier and happier flushes. Bottom casing layers can also be supplemented with additional water after the 1st flush, when casings tend to Pull away from the sides of the container. Water can be added thru this small shrinkage, helping the 2nd flush along.
2.) The bottom casing layer also can act as a "run-off" where excess water and mycelial waste (mycelia produce a yellowish liquid waste when colonizing and fruiting). The casing layer acts as a ste-stool above any excess moisture which may accidentally pool at the bottom of the casing container.
3.) The bottom casing layer acts as a light barrier- so that casings don't pin on the bottom. Pinning on the bottom can be a problem- if mushrooms grow at the bottom of a casing, it is difficult to remove them without disturbing the casing. But pins can rot, opening up a new vector of contamination.
Some people don't use a "bottom casing layer" per se- instead they layer the bottom of the casing container with moistened perlite. This acts to "raise" the substrate and act as a shield against any runoff or mycelial waste which may accumulate there. Adding perlite can also raise the rh (relative humidity) as it wicks water into the substrate.
What are the optimum conditions for casings?
Casings, unlike cakes, go through very distinct patterns.
1.) Once the casing has been created, it should be left to permeate the casing
layerr. This is called the post casing stage. The casing layer should be left
in darkness, with a rh of 90%, high(er) temperatures (84-86 degrees F), and
no CO2 exchange (meaning, no fresh air exchange). This incubation period is
often achieved by cultivators by covering the casing container with foil or
an opaque lid, which has holes poked in it or is set ajar. This will allow for
the CO2 to build up within darkness, while maintaining the high rh
required for this stage. The lid/tinfoil should NOT be put on to seal the container-
many have reported that sealing the casing container results in too much stagnant
air and ends in a sickly sweet smell (meaning: bacterial infection). This problem
is seen little when the container is NOT airtight.
1a.) At this point, a day or so after initially casing, some aggressive mycelia
may have appeared in spots on top of the casing layer. Many people Patch
Case now, to create a more even pinset in the end.
2.) Once the mycelium has appeared in the valeys of the casing layer it´s
time to trigger primordia formation. The mycelium shouldn´t be alowed
to colonize the casing surface since this can easily lead into an overlay.
To trigger pinning, casings need four things: the introduction of fresh air
exchanges (and thus, reduction of CO2 buildup), the introduction of light, and
the reduction in temperature. Ideally, the casing should be kept at 95-100%
RH at this phase, and temps maintained at around 70-75 degrees. To achieve this,
remove the tinfoil/whatever from the casing completely. Place it within an appropriate
moist terrarium (if you have not been colonizing the casing layer within one
already), and fan it. The ambient light of the room should be enough to initiate
pinning, assuming your terrarium has some light and is somewhat see-thru. At
this time, if the casing layer seems dry, you may *finely* mist the casing layer
with water. Not too much: otherwise fragile mycelial strands can die.
How long should I wait to initiate pinning?
Once the mycelium apears in the valeys of the casing layer, mening you can see
myclium strands begining to poke through the casing layer, but the surface of
the casing is not colonized, you should initiate pinning. The more evenly the
valeys of the casing are colonized, the more even of a pinset you will produce.
But, the more closely you approach full colonization, the greater the risk becomes
for overlay to appear. It is difficult to "teach" when to initiate pinning, because
it is a subjective, personal interpretation of when a casing layer is "too" colonized,
or seems to be colonizing "too quickly". Some strains of mycelia are more aggressive
than others (puerto rican mycelia has been reported to be quite aggressive, and
some initiate pinning more quickly than they would for other strains of cubensis)
But, you may even have a great variation among your own casings of the same strain:
one may be almost colonized, while another still has a few days. There is no set
time, you must just judge for yourself when the casing layer is adequately colonized.
What is patch-casing, and why should I do it?
Patch-casing refers to the process in which initial, aggressive "spots" of mycelia poking thru the casing layer are cased again- by adding a small, thin mount of your original casing material to the spots. The initial colonization spots will be the first to appear, usually within the first few days after casing. The point of patch casing is to try and allow the rest of the casing layer to "catch-up" with the initial spots. Usually, an even casing layer will have less of a problem with aggressive spots than an uneven casing layer, but this is not always the case. Just keep in mind that the more evenly colonized the casing layer is, the more chance of an even pinset. And an even pinset means more yield per sq. foot than a non-even pinset.
Why is my casing pulling away from the sides?
Casings will oftentimes "shrink" during the course of colonization, and will
often do so towards the end of a flush.
This has 2 main reasons: Growing mycelium converts the nutrients in the substrate
to mycelium, heat a,d CO2. It has been established that a oyster
mycelium converts up to 50% of the substrate. This subtrate is then "gone",
that´s why the subtrate amount is getting less over the time. The second
reason is is the substrate pulling its water resources together and providing
it for the fruiting stage. If, for example, 100 grams of fresh fruit are picked
from a casing layer, that means the casing has lost at least 90 grams of water
to the fruiting stage. The loss of water is evinced by the "pulling". A pulling-away
casing can often be easily rectified after a flush is harvested: simply by adding
more casing material to the sides where it has pulled, patched any casing layer
that may have been pulled up when you harvested (on the ends of the stems),
and mist with water. The key is to alwas provide the casing layer with water
by misting it so it stays moist, but it shouldn´t be wet. Water is key
to the hobby, but too much can drown!
Why are there mushrooms only growing from the side
of the casing?
Your terrarium and the casing is likely too dry. That´s why the pinhead
formation only takes place between the casing contaner wall and the substrate
where humidity is higher.
Rise the humidity to near 100%RH during the pinning stage and lower it to around
90%RH once the pins have reached 3-4 mm. Alo keep the casing moist (NOT wet) during
the whole cycle by periodicaly misting it when it apears too dry.
What is "overlay"?
Overlay is a term that refers to the condition which can occur to an overly colonized casing layer. A casing layer which has approached 100% colonization risks overlay. Overlay occurs when the fine strands of mycelia die and become hard and matted (as compared to the light, strandy mycelia you will become familiar with.) Overlay is often bright white, since it has become so matted and impenetrable. Mushrooms will NOT grow from overlay, as the mycelia layer is dead on top, and cannot be penetrated from below. Touching overlay (its generally not a good idea to touch casings)- it literally feels like it is one solid piece, as compared to the much more pliant healthy mycelia. Avoid overlay by Initiating pinning at the proper time. Overlay can't be "cured," per se, since the top layer of mycelia is literally dead. But you can help a casing which has overlay by "scratching" it- by dragging a fork, knife, or any other tool which will till the colonized substrate and allow for new colonization. This is to be avoided at all costs for the following reasons. First, it's never advisable to touch the casing layer in any way. It simply opens up another route for contamination to set in. If you scratch, make sure your tools are sterilized (alcohol, boiling, etc.) and you are clean. But do not touch the exposed substrate with your hands, for any reason. Second, dealing with overlay means you're not producing efficiently: when you scratch the casing, the mycelia has to recover from the shock and also re-colonize the casing layer, setting you back at least an appreciable week.
When should I harvest?
Harvest casings all together for best results. If you have achieved an even pinset, your fruits should all become mature at the same time- meaning you can harvest them at the same time. Generally, if they are becoming mature at different times, this means you didn't have an efficently colonized substrate or an even pinset. Harvest can occur right after the veil breaks, up until full maturity when the cap becomes almost convex and drops its spores.
After harvest, you should apply casing material to any areas of the casing layer which were disturbed by harvest (casing layer attached to stems, etc.) and, if necessary, add small amounts of moistened vermiculite to the casing if it has pulled appreciably from the sides of the casing container. This will protect any substrate which has become exposed to open air from possible airborne contaminates. Many people add the amount of water which was lost during fruiting (weigh the harvest and add 90% of that total back in water). At the least, you should mist the repaired casing layer with water. Now, you can put the casing back in its Pre-primordia stage, by again increasing rh to 90%+, increasing temperatures to around 85 degrees F, applying a tinfoil or other layer to prevent air exchange (with holes of course, to insure it's NOT airtight), and limiting light. This will trigger the casing to re-colonize the repaired casing layer, and the cycle begins anew.
|
Threaded
Previous
Index
Next
Some of these posts are very old and might contain outdated information. You may wish to search for newer posts instead.
angryshroom 
Anno
Edit 
Reply 
HC 
_JJ_
GreyMatter
Visigoth
TheCaptain
PhilO'Cybin