Apprentice Casing Tek        
By far, the most frequently asked questions on the Shroomery's Cultivation Board are about problems with casing. Casing is the easiest way to improve your technique and increase your yields, but it's also a source of a lot of headaches and questions until you get the hang of it. For months I was cursed with casings that weren't doing what they were supposed to be doing. Finally, a great and powerful Shroom Mage was able to tell me what I was doing wrong. With this document I am passing his wisdom on to you. Shroom on.
- Shroom Apprentice
The biggest source of casing problems seem to come from over- or total colonization of the casing surface. Discussed at length in The Mushroom Cultivator, the casing layer serves three main purposes:
To protect the colonized substrate from drying out.
To provide a humid micro climate for primordia formation and development.
To provide a water reservoir for the maturing mushrooms.
Overlay is the condition which results when mycelium has been allowed to completely cover the casing surface. It is caused by prolonged vegetative growth temperatures, high CO2 levels, and excessive humidity. If over watered, the overlay will become matted, or, will form a dense, dead layer of cells on the casing surface.
A casing showing signs of overlay will begin to shrink and pull away from the sides of the container. It will also become unreceptive to water, and puddles may form on the surface after misting. If any pinheads form, they will likely do so at the edges of the casing. Most of the pinheads will abort, and only a few mushrooms will fully mature. Once this has happened, the casing layer really isn't a casing layer anymore. It is no longer serving it's three main functions, and has in essence become a second layer of non-nutritious substrate.
As previously mentioned, overlay is caused by prolonged vegetative growth temperatures, high CO2 levels, and excessive humidity. It results when the grower does not take the proper steps to initiate pinning, or, when the grower initiates the pinning strategy too late. As a general rule of thumb, the initiation process should begin as soon as mycelium is first visible in the valleys of the casing layer (or, when you can just barley make it out underneath the surface of the casing). However, Psilocybe cubensis is a species which enjoys high mycelial momentum. Even after initiation of the pinning process, the mycelium will continue to grow for a period of time and consume more of the casing. This is why timing is critical.
1. Temperature & Cold Shocking
According to The Mushroom Cultivator <http://www.promind.com/bk_muc.htm>, the ideal temperature for Psilocybe cubensis during colonization of the substrate and initial colonization of the casing layer is 84-86 degrees Fahrenheit. A 10 degree drop in temperature to 74-78 degrees Fahrenheit is generally enough to initiate the pinning process.
A technique once taught to me by the wise and mysterious "Mr. G" (formerly of Foggy Mountain Farms), is a little more extreme however. It involves cold shocking the casing by covering the tray with tin foil and placing it in the refrigerator for 24 hours prior to birthing into the fruiting terrarium. This cold shock really let's the mycelium knows it's time to fruit, and may serve to not only increase the size of the first flush, but also slow the previously mentioned mycelial momentum. The jury is still out on this one however... Some growers have expressed concerns regarding the bacterial count in their household fridge, while others persist that it's not necessary.
My advice is to try the 10 degree drop first. If that works for you, then stick with it. If however you are still having problems (Perhaps you live in a region where the temperature is too high to provide a 10 degree drop in temperature?), give the cold shock a try; it might just do the trick.
2. High CO2 Levels
The second trigger that lets the mycelium know it's time to fruit is a reduction in CO2 levels in the atmosphere. This can simply be achieved by ensuring that you are fanning your terrarium at least once a day (2-3 times per day may be necessary depending on the size of the terrarium and how many casing trays are inside). Another idea is to incorporate some natural flora into your terrarium, such as a dedicated tray of rye grass that is just there to grow and regulate your atmosphere for you.
3. Excessive Humidity
Generally, casings do not require as much humidity as cakes because it's the casing layer itself that creates the micro climate favorable to pinhead formation and development. As the mushrooms grow, they draw moisture from the casing layer as well as the atmosphere. That being said, the use of cool mist or ultrasonic humidifiers, or perlite humidification, may be too much for your casings.
For the most part, what you use to humidify is going to depend on where you live. If you live in an area where the ambient humidity is generally high, you will probably be able to get away with just a couple of mistings per day. If however, you live in an area where the overall humidity is quite low (Where I live, it gets down to about 30% during the winter) you may need to use perlite or a humidifier setup. The key to remember is that if your casing continues vegetative growth and develops overlay after you've initiated the pinning strategy, your humidity may be too high.
4. Light
Psilocybe cubensis is a photosensitive mushroom, meaning certain spectra of light are necessary for pinhead formation and development. Ps. cubensis responds best to light heavy in the blue- and ultra-violet spectrum, specifically which peak at 370, 440, and 460 nanometers. Red, infra-red, and green light on the other hand are ineffective at initiating pinheads. A few hours of light per day is really all that is needed. If you can see the casings then you are doing fine. Just remember that mushrooms are not like the pot plant that's in your closet; they won't grow bigger or faster with more light :-)
- Shroom Apprentice
50/50+ Casing Tek         Here is a real easy casing mix that works great for cubensis, panaeolus, and other species. Our growers and people worldwide have had great success with this very easy casing method.
At the end of this document, look and read the updated 50/50 + (PLUS) Casing Tek. We highly recommend the 50/50+ tek over any other casing tek out there. The addition of limestone and crushed oyster shell to the 50/50 mix makes a huge difference.
We suggest using plastic trays. You can buy ones at Home depot that can be cut and taped to any size you want. Look in the gardening section by the seedling transplanting trays. They are long, black and thin. They can be cut and taped very easily. If you can't find these trays use anything that will fit to your aquarium size. The idea is to get the best non-transparent (see through) container you can find in the space you have to work with.
You can cut and tape these to fit the exact size of the bottom of your aquarium, leaving about a 1/2" space around your trays so moisture drips down the sides of the glass and not into your tray. You want to use plastic tape and not masking tape or it will fall apart when it gets soggy. You also want to use trays that are black or non transparent so light doesn't seep through to the substrate below or the mushrooms may fruit from under the casing layer and up the sides of the casing instead of on top of the casing layer where they should.
OK, now the fun part!
Take vermiculite, first mix in a bowl with water until its real moist, squeezing out any excess water.
Then drop about 1/2" layer across the bottom of your container.
Then take fresh cakes from the jars, cut them like a cucumber into slices about 2-3" thick, or for best results leave them whole.
Put these slices over the layer of vermiculite. Take some colonized substrate and gently crumble to fill in the places in between the the slices of substrate. This is so your entire layer of substrate is pretty much filled without gaps between the slices or the sides.

***Note***
We recommend cutting out any uncolonized part of the cake/substrate first. What you'll have left is 100% colonized substrate. If this does not apply, then move to the next step.

Next, take a mixture of 50% peat moss and 50% vermiculite, sterilized or pasteurized (more info on that at the bottom) real moist, once again squeeze out excess water, then just lightly place it over the mycelium layer, about a 1/2" to 3/4" just so it covers the mycelium layer. You can also use a little deeper layer, about 3/4" to 1" to allow for a stronger casing layer that will be helpful for more flushes. The downside is it takes a little longer to colonize and fruit. Although in the long run it is well worth it. Only use the 1" thick casing layer if you're using whole cakes or a deep substrate.
Your substrate depth should be no more than about 4" thick. Put your container back in your aquarium right on top of the perlite. I would recommend keeping the light off for the first week, but even leaving it on for 12/12 will not make that much of a difference.
Within about 2 days you'll start seeing the mycelium overtake the casing layer, you want to add a light amount of 50/50 mix over these first high spots so all the mycelium is coming to the surface around the same time, although this is not written in stone.

Within a week to 2 weeks it will be almost completely covered in mycelium. Then the mycelium will stop growing for a few days. The mycelium network is establishing itself, becoming stronger and stronger preparing to produce mushrooms. Then pinning will start. You will begin to see lots of bright white small dots about the size of a pen head. These will form into mushrooms soon thereafter. Harvest time is usually 10-21 days after casing.
As a general rule you do not want to mist your casing during this colonization period, provided you have adequate humidity and fresh air. The ideal humidity for casings is 82% -92%. The reason you don't want to mist your casing soil during this period is because water condensation build up on the mycelium is not good. It will slow down the growth of the mycelium and possibly introduce contaminants easier.
The mycelium will pull most if its moisture from the casing soil itself and from the humidity in the air. Ideally, you should try and harvest your first flush all around the same time, or within a 24 hour period. Then put a light sprinkling of 50/50 mix back over the spots where you pulled the mushrooms from. You want to put down fresh casing in those places where you pulled the mushrooms from to help protect that substrate below. Make sure the casing soil has been sterilized or pasteurized. The reason you want to try and pull all the mushrooms around the same time is that this will help the mycelium network recover faster and prepare for a second flush.
You want to start misting again after you have harvested your first flush. Give it a real good heavy misting so the soil looks moist again, but not saturated. You shouldn't need to mist again until after the next flush, and so on. Now this is not written in stone. This is only if your growing conditions are ideal. Growing outside can be different, you may need to lightly mist the soil every few days because the soil dries out faster. So the rule to follow is if your casing soil looks real dry (starts changing color and getting a real light dried out soil look) then go ahead and give it a light misting. Also, if the casing soil has started pulling away from the side of the container, put in some fresh moist casing soil in there. After the first flush you can look forward to your next flush in about a week.
You will get huge flushes from this method. If somewhere along the way you start to see contamination in any part of the soil, cut it out immediately, making a big cut several inches away from the contaminated part. Putting down a big fresh spot of casing soil where you cut it out. Its pretty typical for casings to get hit by the green mold Trichoderma after a few flushes, but by keeping your hands, arms and tools clean, by wearing a face mask and using fresh sterilized soil for patches, this will help prevent it from happening too soon.


50/50+ (Plus) Casing Tek
Adding 4% agricultural hydrated lime and 15% crushed oyster shell, by volume, to the over all 50/50 mix is a much better casing soil. The soil seems to give the mushrooms more support so when your harvesting your not digging out deep chunks of mycelium from the substrate, instead they pull out very easily from the surface. The mushrooms also seem to grow much bigger this way being they have a stronger base into the mycelium network. They also like the lime and calcium from the oyster shell, and you will see less contamination in the casing soil with the lime added. When mixing the casing substrate, a lot of the oyster shell and lime sinks to the bottom, so mix it and squeeze it real good when placing over the substrate.

IMPORTANT NOTE:
Be sure you buy horticultural hydrated lime, not dolomitic or other kinds, or it will burn the mycelium and they wont grow. So look at nurseries for horticultural hydrated lime, it usually says "to sweeten the soil on the bag".

NEW UPDATE:
Although most people, including us, have great success from using horticultural hydrated lime, some do not. They end up burning their mycelium or the mycelium just never colonizes through to the casing soil. We think perhaps the hydrated lime they are buying has a much higher alkaline level then then the Hi Yield brand we are using. Hi Yield brand is our preference and works great for us. But just to play it on the safe side, we are going to suggest you buy calcium carbonate. A ground calcium carbonate is a gentle buffer. Some brands of hydrated lime are not. Calcium carbonate is basically ground up limestone, a soil sweetener. It works just as good if not better then horticultural hydrated lime. Its a much safer bet as well. You should be able to find calcium carbonate in just about any garden supply store.
Another tip, look for the large chunked oyster shell sold at feed stores. The fine powder shell is fine, the but the large chunked shell gives a much better texture and the mushrooms grow even better on this soil. You can find oyster shell anywhere birds are sold, or at most feed stores.
The exact mix, to fill a filter patch bag 3/4 full is:
15 1/2 cups vermiculite
15 1/2 cups peat moss
4 1/2 cups crushed oyster shell
1.2 cups of hydrated lime
15 cups of distilled water (1 cup short of a gallon of bottled water) 16 cups = 1 gallon

This will make enough for a good 3-6 medium to large casings depending on how big they are.

Tips on sterilizing and pasteurizing substrate:
There has been a lot of discussion on whether it's better to sterilize the casing soil or not. In my friend's studies, he has found that sterilizing is better. Some people like to pasteurize it. That's OK, but he prefers to sterilize it. My friend buys filter patch bags from Myco Supply or Fungi Perfecti or various other vendors </vendors.php>. These are large autoclavable bags (meaning they can go in the pressure canner and survive the heat without melting) with a filter on them for gas exchange. Although for sterilizing the casing soil, the patch does not matter. Basically after mixing up all the dry ingredients, (pulling out all the sticks from the peat moss) for the 50/50+ mix, add in your water. Mix really good, have your filter patch bag handy, squeeze out most of the water from the casing mix. Squeeze so its just slightly dripping then put it into the bag. Fill the bag about 3/4 full. Put this in your pressure canner and be sure to keep it away from the sides of the pressure cooker. Sometimes the filter patch bag will melt if it touches the sides. Sterilize at 15 p.s.i for 45 minutes.
Let this completely cool before using. Now at this point, the pressure cooker is going to take out some of the moisture. Just make sure when you go to use it as your casing soil you squeeze out the water until its barely dripping and not running water. Here is another strange kicker, my friend puts his bag outside... in the shade... with the top folded/rolled down with a plate on the top to hold the bag shut so that no bugs can fly in. He lets it sit outside for a few days or weeks before using it. When you sterilize it, you're killing any eggs of larva or other unwanted bacteria in the vermiculite. You're actually killing more in the peat moss, well.. this is only his theory, no scientific data to support this, but... by putting it back outside, it regains some of the needed micro organisms' that the casing soil lost during sterilization. Now perhaps his theory is right, or perhaps he's just been lucky... but he has seen a lot less Trichoderma hit his casings since he started doing this.
Another important note, when the time comes to use the soil make sure the moisture content is correct.
If too moist, squeeze the water out until its barely dripping.
If too dry, then add in some bottled mountain spring water then squeeze it back out.

Another tip, if you don't have the resources to buy the filter patch bags, the plastic bags that the peat moss and vermiculite come in also work fine as well. Just cut the rubber zipper seal off of them so they don't melt and use them the same as above. Just make sure you keep them away from the edge of the cooker.

ADDITIONAL UPDATE:
Use a layer of 50/50+ casing tek as the bottom layer instead of plain vermiculite, it works better.
If you don't own a pressure canner/cooker then pasteurize this mix. You pasteurize by putting the casing soil inside, say an old pillow case, twist and tie up the top so that no casing soil leaks out. Then put it into a pot of water. The water temperature should be around 150°F. Maintain this temperature for an hour.
A tip on humidity:
If you don't have a humidity gauge, one sure way my friend has found to determine humidity from looking at his gauges, is by judging the condensation on the walls of your grow chamber. For casings you want around 82%-92% humidity. If you see the walls of your grow chamber just sweating away with condensation and they're dripping constantly, then you more then likely have 100% humidity, this is fine for cakes but not casings.
To judge 82%-92% humidity you should only see light condensation on the walls with the occasional dripping. This is after some fresh air has been pumped into your chamber and you let it sit for an hour or two. Also, those cheap plastic gauges you buy from pet stores, they don't work. Even most of the ones sold by cigar stores are made by plastic companies. For a good analog meter, cigar stores carry one made by Cigar Perfect for $12. This model is made by an instrumental company, and not a plastic company and works well.
Almost every singe flush you see on this www.thehawkseye.com website has used the 50/50+ formula described above for casing... it works!!!!
by Ryche Hawk
reformatted and spell checked by Lana

 

Oss/Oeric Casing Mixture        
Use the following ingredients to create the casing material. Then substitute it into any casing method.
7.5 liters peat
3.5 liters vermiculite
4 liters fine washed sand
2 liters calcium carbonate (finely crushed oyster shell)
Stamets Casing Mixture        

The recipe is originally from Growing Gourmet & Medicinal Mushrooms, by Stamets.
Use the following procedure to create the casing material. Then substitute it into any casing method.
Ingredients:
10 units peat
1 unit calcium sulfate (gypsum)
1 unit calcium carbonate (chalk)
Procedure:
Use calcium carbonate to adjust pH of peat.
Mix dry components - add water slowly, 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.
Sphagnum Moss Tek        

Take the cakes out of the jars, and put them on a wire screen table that completely covers the fruiting container, and is about 2 inches off the bottom; quarter-inch squares in the screen work well. I like to use wet perlite in the bottom of the cooler, under the table of wire so the kids have enough humidity.
This is the good part. Go to Manards hardware store, or some store like that, and get sphagnum moss. This moss grows in swamps, I have seen it in da U.P. in many bogs. You buy it in a green bag in the garden section, and it says "All Natural GREEN MOSS Decorative Sheet Moss" on the front of the bag.
Take the bag home, and wash it with regular water, paying attention to the removal of sticks, dirt, and other shit that is not moss. Other wise you get cake injuries and weird green fungus from the sticks, and germs and other contamination from the dirt.
Squeeze it well, but leave it damp, and place the sphagnum moss around every cake. I didn't put any moss on top of the cakes, I thought it may interfere with photo-tropism. When the basidiocarps begin coming up, dampen the moss carefully using an empty spore syringe. Keep the moss damp, if you put too much water in the moss, it is alright, it will go into the perlite.
Here is what happens - the cakes will extend mycelia into the moss, and when the mushrooms come up and the moss gets wet, the fungus puts this water into the mushrooms and makes them grow fast and fat as hell. Than they elongate and get big. When some 'shrooms start getting dark streaks in them, you know that you have been watering them too much.
Now I don't know if this is a new or good idea or what, but I think it works well, and I will continue my mycologic experimentations until I am dead because I love everything about it, and I will even teach my grandchildren how to do it when I am old and decrepit. Put this in your growing techniques section of the Shroomery if you want, it is a good way to do it.

 

Does a casing require a fruiting chamber? 
The casing layer is what provides the moisture for the mycelium, but the humidity around the casing needs to be high, otherwise it will simply dry out. Usually the ambient humidity of a room is not high enough to provide this. It's also a good idea to keep the casing covered in order to decrease the chances of airborne spores landing on it, as many mushroom pathogens like Trichoderma can ruin your crop. There are two ways to do this -- you can either create a separate fruiting chamber that is humidified to house the casings, or you can case your mycelium in a tall container and cover it, so the casing container itself acts as the fruiting chamber.

Creating a separate fruiting chamber:

This has the advantage of housing several separate small casings which increases the chances of success. There are a lot of ways to create a separate fruiting chamber -- it's just a large bin that is humidified. You can use a thick layer of wet perlite at the bottom of a covered plastic bin, or you can use an external humidification device, such as a cool mist humidifier or a fish tank bubbler to humidify your bin. (see ShroomGod's Humidifier Tek ) As long as your casings are in this humidified container, the casing should not dry out with proper misting.

Using the casing container itself as a fruiting chamber:

This has the advantage of a much larger casing area, since any large bin, itself, can be cased. There is also no need for any external means of humidification -- no perlite is needed because the humidity simply comes from the casing, itself. The casings are much larger, and are isolated from one another in separate bins. The casing container should be large enough so the fully-grown mushrooms won't hit the top (not a big deal, but it can't be a good thing) -- usually a 12" deep bin is fine. This bin is cased end-to-end, and then it's covered with saran wrap, and the casing is allowed to colonize at fruiting temperatures.

NOTE: At this point you can take advantage of the elevated CO2 levels by only fanning every other day -- this will make the casing colonize quicker.

Once the mycelium is poking through in different spots, fruit the casing as normal, and keep it covered, fanning and misting it every day. Just mist it enough so the casing never looks dry -- it doesn't take much! You may want to put drainage holes at the bottom of the container, so pools of water don't collect. After a week or two you should have lots and lots of mushrooms!

by micro

 

Casing material pH and why it is important. 
"pH", is a measure to describe the acidity of a medium.
pH 7 is neutral; higher means alkaline, lower acidic.

Peat is a major constituent of preferred casing mixes. The pH of peat is variable, dependent on the source it came from. Meaning, the pH of peat differs from various sources.
The preferred pH range of a casing mixture is 6.5 to 8. 7.5 is optimal.
Peat is acidic. Consequently, to achieve an optimal pH range of a casing mix, the pH of the casing mixture must be adjusted accordingly (within the range of 6.5 to 8).
The pH of the casing must be within certain limits to support strong mycelial growth. An overly acidic or alkaline casing mixture will depress mycelial growth and supports unwanted competitors.
It is generally easier to make casing materials more alkaline (i.e., increasing the pH) than it is to make them more acid (i.e., reducing the pH).
A movement of 0.5 is easy but, because the pH scale is logarithmic, a movement on the order of, 2.0 points becomes more difficult because there is a factor of 10x between each full point, so pH 5.0 is actually 100 times more acid than pH 7.0.

There are several common types of lime available for use, though care should be exercised with all of the products. Lime is caustic and a skin and eye irritant and can be dangerous if misused. If you choose to use such products, carefully read and follow all manufacturer directions exactly. The major types of lime products include:
Hydrated Lime: fast acting, but not long lasting. It is very effective to produce a fast change in pH level. It is also the "strongest" form of lime generally available, and you must follow all manufacturer precautions, since your skin and eyes can be easily irritated or burned if the product is misused.

Ground Limestone: a naturally occurring type of limestone that has been ground to a fine powder. How quickly it will act to modify pH and how long it will persist depends on how finely it was ground.

Generally, ground limestone is weaker than hydrated lime, needing about 30% more to raise the pH by the same amount. It has the advantage, however, of usually being significantly cheaper than the hydrated lime, and usually works more slowly and lasts much longer.

Mixed Lime: usually sold under a brand name. Most brands contain a variety of particle sizes to provide some immediate benefits, as well as a longer persistence. (this is often referred to as "time released" lime).

pH gradually falls to less than optimal by the end of cropping due to acids secreted by the mushroom mycelium. Consequently, a long lasting buffering agent is preferable.

If you wish to achieve optimal results when adjusting pH, it is highly advisable to use litmus strips (with color chart), or acquire a pH test probe (available at most garden supply stores, under $20) to accurately test, and adjust the pH of your casing mix, prior to application.

Doing all other cultivation steps properly, then applying a casing mixture outside the proper pH range, most often creates poor cropping results.


by SixTang

How moist should the casing mixture be? 
The casing layer should me moist, but not wet.
A good way to determine the correct moisture is to squeeze a handful of casing layer in your hand. When you squeeze it, not very hard, a few drops of water should drip out.

Can I use hydrated lime in my casing mixture? 
You can, but you have to be very carefull how much you add.
In theory one should add 2/3 hydrated lime compared to the amount of limestone(calcium carbonate)needed.
The problem is that you have to add exactly the right amount if you use hydrated lime. If you add too much, the pH will go towards 13.
If you use limestone, the pH can't go above 8, despite the amount used.
To prevent this make sure to measure the pH of the casing material, it shouldn't go over 8

What do I do after applying the casing layer? 
Once the casing has been created it should be left at colonization conditions to allow the mycelium to permeate the casing layer. This is called the post casing/pre pinning stage. The casing layer should be left in darkness, with a RH of 95 %, incubation temperature (80 - 84°F), and no CO2exchange (meaning, no fresh air exchange). In small setups this incubation period is often achieved by covering the casing container with aluminium/tin foil or an opaque lid. If you use a lid and the lid closes very tightly, some small holes should be poked into the lid to allow for some gas exchange.
If you use foil holes are not needed since the foil doesn't seal the casing container off completely.
The cover will allow for the CO2 to build up within darkness, while maintaining the high RH required for this stage.
A day or two 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 pin set in the end.
Once the mycelium has appeared in the valleys of the casing layer it's time to trigger primordia formation. The mycelium shouldn't be allowed to colonize the casing surface since this can easily lead into an overlay. To trigger pinning, casings need three things:
the introduction of fresh air exchanges (and thus, reduction of CO2buildup), 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 and fan it 1-2 times a day.
Terrarium refers to any enlosed container with at least one translucent side, idealy at the top(terrarium, aquarium, rubbermaid box with a lid...)
The ambient light of the room should be enough to initiate pinning, assuming your terrarium has some light and is somewhat see -through. At this time, if the casing layer seems dry, you *lightly* mist the casing layer with water. Not too much: otherwise fragile mycelial strands can die. The casing should remain moist but not wet.

When should I put the casing into the fruiting chamber? 
Once the mycelium appears in the valleys of the casing layer, meaning you can see mycelium strands beginning to poke through the casing layer, but the surface of the casing is not yet colonized, you should initiate pinning.

The more evenly the valleys of the casing are colonized, the more even of a pin set you will produce.
The mycelium usually continues to grow for a few days further into the casing layer after the pinning has been initiated depending on strain. Some strains of P. cubensis 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) . There is no set time, you must just judge for yourself when the subsurface of the casing layer is adequately permeated.

You initiate your casing when mycelium has peaked through the surface at multiple points seen around the entire area of the casing surface. This increases the likelihood that the mycelium has colonized throughout the subsurface layers of the casing layer. You want the casing soil to be colonized, but not the casing soil surface!
Look at the PICTURE in TMC of the large bulk tray of pasteurized cased straw. You won't see any mycelium at the surface of the casing, ONLY FAT SHROOMS.

You wait for the mycelium to PEAK out at multiple spots, to know that it has PROBABLY made its way up to the surface everywhere, but not on the surface.
If you can consistently lay down an even casing layer upon an even substrate, and you KNOW how long YOUR particular strain you are growing takes to colonize right up to the surface, but not on the surface, INITIATE BEFORE it comes out on to the surface.
Wait to see some surface colonization, peaking out, if you don't know how long it takes!
So the more you know your strain(substrain) the less mycelium you need to see on the surface of the casing layer!

But again, you want the subsurface layers of the casing colonized, NOT THE SURFACE itself.
If this happens, we speak of OVERLAY.

Overly is not such a big deal with P. cubensis, the casing will fruit nevertheless, but not as good as with a properly maintained casing

How to apply an even casing layer? 
An even casing depth is important to achieving maximum yield and performance from all cased substrates. Regardless of how level (or un-level) the substrate surface is, the following tip will help insure consistent casing depth. An evenly laid casing (measured in depth to substrate level, not as in parallel to the floor) helps casings to colonize faster and more evenly, promotes even pin sets and therefore increases yield. An even casing depth causes the casing to colonize at the same rate across the tray so that mycelium reaches the surface at the same time. This can reduce pin initiation period compared to an uneven casing colonization, and it will definitely aid in pin set.
Applying an even casing layer becomes increasingly difficult on larger trays, uneven substrate surfaces, or casings in the bottom of deep bins (shroomgod straw bins for example). Making sure that the depth of the casing is the same over the whole tray, regardless of the substrate surface being actually level or not is the goal of this tip. This can be done by using depth rings.

Materials needed:
1. Some type of tube (large diameter PVC pipe, tennis ball tubes, even paper towel tubes or rings made of durable paper)
2. Utensil for cutting tube material
3. Ruler for measuring
4. One colonized tray of substrate ready for casing
5. Casing material of choice

Cut rings of large diameter PVC, tennis ball tubes, even paper towel tubes to the width that you want your casing depth to be (I'd say somewhere between .5 and 1.25 inches for most people, with deeper substrates calling for deeper casings). Make enough rings to spread out over the substrate surface without too much space between them.

Lay these rings over the substrate surface, then apply casing material of choice to the tops of the depth rings. Gently remove the rings after casing is applied. This ensures an even casing depth relative to the substrate surface. Simple really.

Oh yeah, the more level the substrate is to begin with, the easier things will be. But, nothing ever goes perfectly.

by mycofile

What is "cold shocking"? 
Exposing the cakes or casings to cold temperatures for around 24 hours is supposed to trigger pinning. The opinions whether it is needed with P. cubensis or not vary, but so far it's not known that it would do any harm doing so.
It seems to be beneficial with some strains which don't form pins easily. Make sure that you wrap the cakes or casings well before putting them into the fridge, since the fridge is often not the cleanest place in terms of mushroom cultivation.

cubensis eats substrate best at 86 F. The further you drop the temperature from that temp, without passing a critical temp that kills, the faster you stop it from EATING. When the mycelium stops eating and is exposed to light, oxygen it begins to pin.

Going from 86 to 75 may not be significant enough to immediately trigger fruiting. The mycelium may continue to feed until the OTHER stimuli trigger fruiting. So cold shocking may speed up fruiting, as several members here have stated.

My concern with it would be an extension of the lag time between frutings due to the GREATLY decreased temperature exposure initially, and then the maintainance at lower temps then optimum for growth rate. It seems to me it would be better to only slightly lower temps, and combine it with the OTHER stimuli to get fruits. It may take longer to get the first flush, but it MAY ALSO take less time to get the second, third, fourth, etc....

I never cold shock cubensis, NEVER needed to. Just trying to see the benefits and ways them against any pitfalls.

I don't grow cakes either.

Definetly can see it being beneficial for STUBBORN CAKES or CASINGS that refuse to Stop vegetating regardless of exposure to the other STIMULI. The Mycelium has to STOP growing to fruit.

Dropping temps 10 degrees is not the same as dropping it 40 degrees. The former just slows down the growth. The latter can STOP IT. Once the mycelium stops growing it starts the pinning process, after a short lag to GET READY. COLD SHOCK could make this happen faster. If it does, like wise it can make the in between flush period, LONGER. Temps beneficial to fruiting are Lower then temps beneficial to growing(eating). The mycelium gathers nutrients in FEEDING mode, stores them, and uses them to develope the first and second flush. Then it has to feed some more to make more pins and develope them. This is why I think Cold shocking might speed up pin sety, but slow down the time in between flushes.

by Teonan

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.

What is "deep scratching"? 
Deep scratching is a recovery tool used to recover damaged casings from OVERLAY.
It is accomplished by scratching the surface of the casing to a depth of a few milimeters with a fork or similar device.
If you have successfully harvested a good first flush, leave your casing alone in the fruiting chamber. Mist it, bring water content back up to where it was prior to the first flush, and wait for the second flush.
Do not deep scratch, unless it is having problems pinning, problems associated with overlay, which is directly related to over incubation, and a lack of air exchange.
Deep scratching after a healthy first flush is BAD INFORMATION. Pins for your first and second flush are produced during the initial intiation. If you deep scratch after harvesting the first flush, you kill all the pins for the second flush. This deep scratching at this point does two things, it prolongs the time between the first and second flush, and more importantly, it will spread any contamination that might be presently contained.
Some species of mushrooms actually benefit from deep scratching prior to the first flush, but cubensis is not one of them.
misting casing going to cause pins to abort ? 
No, gently misting the casing won´t make pins to abort.
The rule is to never water the casing heavy so that it is really wet but mist it gently from time to time so the casing remains moist all the time. The keyword is moist.
Heavy watering could harm the pins and it will also seal the casing surface and make the conditions less favorable for the mushroom formation. But misting is OK and necessary.
Try not to mist the bigger mushrooms directly since this can cause mushroom rot. At this stage try to mist the casing surface between them, although a few drops directly on the mushrooms won´t do any harm.