Difference between revisions of "Casing Layer"
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* 1x Cup of Peat Moss (1 Part) - Must be plain organic, without any additives, some manufacturers add nutrients to their product. | * 1x Cup of Peat Moss (1 Part) - Must be plain organic, without any additives, some manufacturers add nutrients to their product. | ||
* 1x Cup of Vermiculite (1 Part) | * 1x Cup of Vermiculite (1 Part) | ||
− | * 1x Tablespoon of Gypsum to the Peat (10% to the Peat) | + | * 1x Tablespoon of [[Gypsum]] to the Peat (10% to the Peat) |
* 1x Teaspoon of Hydrated Lime (3.3% to the Peat) | * 1x Teaspoon of Hydrated Lime (3.3% to the Peat) | ||
* Approximately 100ml water per cup of Peat | * Approximately 100ml water per cup of Peat | ||
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# Place the Peat Moss in a mixing bowl and use your fingers to break everything up to a fine powder, the finer the better. | # Place the Peat Moss in a mixing bowl and use your fingers to break everything up to a fine powder, the finer the better. | ||
− | # Add the Gypsum and Hydrated Lime to the bowl and mix well. | + | # Add the [[Gypsum]] and Hydrated Lime to the bowl and mix well. |
# Slowly add the water and bring to field capacity, you want no water to drip when you pick up a hand full, and a little stream of water when you squeeze. | # Slowly add the water and bring to field capacity, you want no water to drip when you pick up a hand full, and a little stream of water when you squeeze. | ||
# Place the Vermiculite in a separate bowl and cover completely with water. Let it soak for a bit and then strain the water off properly. | # Place the Vermiculite in a separate bowl and cover completely with water. Let it soak for a bit and then strain the water off properly. | ||
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An acidic casing layer will favor Trichoderma and other molds, while established mushroom mycelium is more tolerant of a highter pH. Peat Moss is naturally acidic, that's why we use the Hydrated Lime to raise the pH to a starting point of around pH8 and to make it inhospitable to competitor fungi. I use Sphagnum Peat Moss which is pH balanced so I use about half the Hydrated Lime (1x teaspoon per 2x cups of Peat). Before I pasteurize I test the pH with a soil pH meter and adjust accordingly. | An acidic casing layer will favor Trichoderma and other molds, while established mushroom mycelium is more tolerant of a highter pH. Peat Moss is naturally acidic, that's why we use the Hydrated Lime to raise the pH to a starting point of around pH8 and to make it inhospitable to competitor fungi. I use Sphagnum Peat Moss which is pH balanced so I use about half the Hydrated Lime (1x teaspoon per 2x cups of Peat). Before I pasteurize I test the pH with a soil pH meter and adjust accordingly. | ||
− | The Gypsum contains both calcium carbonate and sulfur, thus it tends to keep the pH near neutral, acting as a pH buffer and preventing swings as the metabolites try to push the pH down. | + | The [[Gypsum]] contains both calcium carbonate and sulfur, thus it tends to keep the pH near neutral, acting as a pH buffer and preventing swings as the metabolites try to push the pH down. |
Revision as of 11:16, 1 December 2020
What is a Casing Layer?
A casing should be a non-nutritious top layer that is placed over a colonized substrate, if you use a nutritious casing it will be colonized by the mycelium and then it will no longer be a casing. The purpose of a casing is to create a microclimate above the substrate to help induce pinning, it also supplies moisture to the substrate and the developing fruits and prevents the substrate from drying out too quickly. The high-humidity microclimate helps to minimize side pinning by making the conditions at the top of the cake more favorable for fruiting than the sides. Some casings also contain microorganisms that are both necessary for fruit-body formation in some species, and can also help fight off contaminations.
Benefits of a Casing Layer
- Provides a humid microclimate on the surface of the substrate in lower humidity environments.
- Prevents the substrate from drying out too quickly in lower humidity enviropnments.
- Supplies moisture to the substrate and developing fruits.
- Helps prevent side pinning.
- Some species won’t fruit at all without the application of a casing.
Downfalls of a Casing Layer
- Casing layers do involve an extra step in the growing process, which means more time and resources to get the job done.
- They can also be susceptible to contamination, especially in fruiting environments with limited amounts of fresh air.
When to use a Casing Layer?
Since not all mushrooms really benefit from a casing layer, using one can sometimes be counterproductive. So use it if you have to, otherwise don't. Cubensis generally don't require a casing when fruiting in a Monotub or SGFC (with the exception of a few slow fruiting strains like Penis Envy) as the humidity is easily kept to near 100% due to the small size. When using a grow tent you should always use a casing as the humidity is lower (around 90%) and fluctuates a lot, if you don't you will get side pins galore and the substrate will dry out more quickly.
How to make a Casing Layer
There are many ways to skin a cat, but here's how I do it:
Ingredients:
- 1x Cup of Peat Moss (1 Part) - Must be plain organic, without any additives, some manufacturers add nutrients to their product.
- 1x Cup of Vermiculite (1 Part)
- 1x Tablespoon of Gypsum to the Peat (10% to the Peat)
- 1x Teaspoon of Hydrated Lime (3.3% to the Peat)
- Approximately 100ml water per cup of Peat
Directions:
- Place the Peat Moss in a mixing bowl and use your fingers to break everything up to a fine powder, the finer the better.
- Add the Gypsum and Hydrated Lime to the bowl and mix well.
- Slowly add the water and bring to field capacity, you want no water to drip when you pick up a hand full, and a little stream of water when you squeeze.
- Place the Vermiculite in a separate bowl and cover completely with water. Let it soak for a bit and then strain the water off properly.
- Now combine the Vermiculite and Peat and mix well.
Pasteurization:
Now that we have made our casing it needs to be pasteurized before we can use it as a casing layer is prone to some form of contamination. It needs to be pasteurized and NOT sterilized. Sterilizing it will kill off the beneficial microorganisms that is responsible for simulating primordia and fighting off competitor fungi like Trichoderma and other molds.
Pasteurize the casing for around 1 hour. You want the inside of the mixture to reach a temperature between 60C and 80C and keep it there for 30 mins. For best results use a probe thermometer to see when the mixture reaches pasteurization temperature and eliminate the guesswork.
After pasteurization let it cool down to room temperature before using it, otherwise it will harm your mycelium.
Applying the Casing Layer:
Gently cover the top of your substrate with casing material about 2cm thick. You want all the mycelium to be covered so that none of it is visible. There is no need to be super sterile during this process but do it with clean and sanitized hands or even better, wear nitrile gloves.
Extra notes:
Obviously you can adjust the recipe to make more should you need to, rather make too much than too little. For my tubs I find that 1x cup is just not enough so I normally make double the recipe.
An acidic casing layer will favor Trichoderma and other molds, while established mushroom mycelium is more tolerant of a highter pH. Peat Moss is naturally acidic, that's why we use the Hydrated Lime to raise the pH to a starting point of around pH8 and to make it inhospitable to competitor fungi. I use Sphagnum Peat Moss which is pH balanced so I use about half the Hydrated Lime (1x teaspoon per 2x cups of Peat). Before I pasteurize I test the pH with a soil pH meter and adjust accordingly.
The Gypsum contains both calcium carbonate and sulfur, thus it tends to keep the pH near neutral, acting as a pH buffer and preventing swings as the metabolites try to push the pH down.