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 Stamets: The Mushroom Cultivator, 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