Emily Johnson
Casing is a crucial element of mushroom cultivation that is widely used by experienced growers and can be beneficial for beginners. It is a soil-like material that is applied to the surface of a growing medium, such as sterilized sawdust or compost, in which mushroom mycelium is already growing. The purpose of the casing is to provide the necessary conditions for the development of the mushroom fruiting bodies, which are typically eaten. Casing layers are not supposed to be nutritious but rather provide a moist and aerated environment for mushrooms to develop in. They can also help maintain a high level of humidity at the surface of the substrate, even if the air in the fruiting environment is less humid. While it is possible to grow mushrooms without a casing layer, it can provide much-needed protection and improve yields.
| Characteristics | Values |
|---|---|
| Purpose | Induce fruiting, supply moisture, and provide necessary conditions for the development of the mushroom fruiting bodies |
| Materials | Organic, inorganic, or a mixture of both. Peat moss, vermiculite, coconut coir, sheet moss, compost, sawdust, etc. |
| Thickness | 1/4"-1/2" or 1/2"-1" |
| pH | 6.2-7.2 |
| Pasteurization | Recommended before applying to the top of the block |
| Application | Added after the substrate has been fully colonized by the mycelium |
Explore related products
What You'll Learn
Casing layers are not always necessary
Coconut coir is a popular casing layer that is easy to use and yields great results with healthy cultures. It is the crushed outer shell of the coconut fruit, excellent at retaining water, and can hold nearly as much as vermiculite. Unlike other casing materials, coconut coir is nutritious and is often used as a bulk substrate.
The ideal pH for a casing layer in mushroom cultivation is typically in the range of 6.2-7.2. This pH range provides the right balance of nutrients and helps to reduce the risk of contamination by harmful bacteria or mold. It is important to note that different species of mushrooms may have different pH requirements, so it is recommended to research specific mushroom types before creating a casing layer recipe.
Creating a casing layer involves mixing materials such as peat moss and vermiculite with water to achieve "field capacity." This means that when you squeeze the mixture in your hand, only a few drops of water come out. The casing layer is then applied to the top of the bulk substrate, creating a microclimate that encourages pinning and fruiting.
While casing layers can improve yields and promote pinning in non-ideal conditions, they are not always necessary for successful mushroom cultivation. With proper care and attention, mushrooms can be grown without a casing layer, depending on the specific variety and growing conditions.
Real Mushrooms: Flowdose's Natural Superfood
You may want to see also
The ideal pH range for a casing layer
Casing layers are not meant to be a source of nutrition for the forming fruiting bodies. Instead, they provide a moist and aerated environment for them to develop in. Casing layers are not always necessary, but they can improve oyster mushroom yields and promote pinning in non-ideal conditions. They are also crucial for the formation of fruiting bodies in some mushroom strains.
According to scientific research, the optimal pH level for mycelium growth ranges from 6.7 to 7.7. However, when the pH level drops below 7, various types of green moulds (Trichoderma) may appear in the casing layer, and the risk of contamination increases as the pH level decreases. Therefore, the pH level of the mixture is usually adjusted to be slightly higher, typically between 7.2 and 7.5.
To adjust the pH level of the casing layer, you can use hydrated lime (calcium hydroxide), quick lime, or pickling lime. The amount of lime needed will depend on the starting pH of your water. If you are starting with neutral water (pH 7.0), use 1/8 teaspoon of hydrated lime for every gallon of water. Mix well and let it sit for about an hour before checking the pH again, as the lime takes time to dissolve and affect the pH level.
Best Cream Options for Mushroom Sauce
You may want to see also
Casing layer materials and their preparation
Casing layers are used to cover a colonized substrate to induce fruiting and maintain moisture. The materials used for the casing layer are chosen for their ability to retain water, which is essential for fruiting conditions and fruit body growth.
Casing Layer Materials
Common materials used for the casing layer include peat moss, vermiculite, and coco coir. Sheet moss can also be used as a casing for oyster mushrooms. Vermiculite is favoured for its ability to hold water—up to 16 times its weight—and its inert nature, which means nothing can grow on it. It is also inexpensive and readily available. Peat moss is another type of unconsolidated soil material that consists of organic matter accumulated under excessively moist conditions.
Preparation
The casing layer should be about 1/4"-1/2" thick across the top of the block. A 50/50 mix of peat moss and vermiculite is often used, to which water is added until the casing layer has reached "field capacity". To test this, squeeze the mixture in your hand. If no water comes out, it is too dry; if a stream of water is produced, it is too wet. You want a few steady drops to come out when you squeeze the mixture as hard as you can.
While sterilization is not necessary, pasteurization is recommended to prevent contamination. This can be done by simmering the mix in a pot for 45-60 minutes. Mineral supplements can also be added to provide essential minerals for mushroom growth and to balance the pH of the casing. For example, hydrated lime (calcium hydroxide) can be used to raise the pH and reduce soil acidity.
Mushroom Power: AG1's Natural Medicine
You may want to see also
Explore related products
The benefits of using a casing layer
Casing layers are not always necessary for mushroom growth, however, they are proven to improve yields and can promote pinning in non-ideal conditions. The use of a casing layer depends on the type of mushroom you want to cultivate. Here are some benefits of using a casing layer:
Protection
A casing layer provides much-needed protection to your mycelium growing project. It creates a microclimate that encourages pinning, which is the early stage of mushroom development.
Moisture Retention
Materials used for casing layers are chosen for their ability to retain water, which is essential for maintaining proper fruiting conditions and initiating fruit body growth. For example, coconut coir is excellent at retaining water and can hold nearly as much as vermiculite.
Discourages Pests
Coconut coir also discourages many types of pests from infesting your mushroom cultivation.
PH Control
Mineral supplements such as lime and vermiculite are commonly combined with coconut coir or peat moss to keep pH levels and potential contaminants under control. The ideal pH for a casing layer is typically in the range of 6.2–7.2, providing the right balance of nutrients and reducing the risk of contamination by harmful bacteria or mould.
Ease of Use
Creating a casing layer is not complicated and can be done with just a few materials and some household equipment.
Fresh Mushrooms: Sulfites or Not?
You may want to see also
How to apply a casing layer
Applying a casing layer to your mushrooms can help create the best environment for them to flourish. The casing layer can be made from various materials that are organic, inorganic, or a mixture of both. Many growers use peat moss, which can hold up to 10 times its weight in moisture. Others use coco coir, which retains moisture and discourages pests.
To apply a casing layer, start by pasteurising the mixture. Heat the centre of the mixture to between 65-80°C, and maintain this temperature for about 30 minutes. Then, allow the mixture to cool to room temperature. It is important to ensure that the casing has cooled before use, as applying hot casing to the block can kill the mycelium and prevent fruiting.
Next, prepare the casing layer mixture by adding water until it reaches "field capacity". To test this, grab a handful of the mixture and squeeze it. If no water comes out, it is too dry. If a light squeeze causes a stream of water, it is too wet. You want to be able to squeeze the mixture tightly and only have a few steady drops come out.
Once the mixture is ready, apply the casing about 0.5"-1" thick across the top of the block. There is no need to be overly sterile during this process, but it is good practice to wash your hands and wear gloves. After applying the casing, place the newly cased blocks in the fruiting chamber and wait. Ensure that the humidity is sufficient and that the casing layer does not dry out completely. After 4-7 days, pins should start to appear through the casing. At this point, continue to monitor the humidity as the mushrooms grow.
Bob Dylan's Mushroom Trip: Exploring His Creative Mind
You may want to see also
Frequently asked questions
A casing layer is a soil-like material that is applied to the surface of a growing medium, such as sterilized sawdust or compost, in which mushroom mycelium is already growing.
A casing layer provides the necessary conditions for the development of the mushroom fruiting bodies. It also helps to maintain a high level of humidity at the surface of the substrate, even if the air in the fruiting environment is less humid.
The ideal pH for a casing layer is typically in the range of 6.2-7.2. This provides the right balance of nutrients and helps to reduce the risk of contamination by harmful bacteria or mold.
The casing layer is typically added once the mycelium has covered at least 95-100% of the substrate and hyphal knots have begun to form. This ensures that the mycelium has sufficient energy to support mushroom growth.
Common materials used for the casing layer include coconut coir, peat moss, vermiculite, and limestone flour. These materials help to retain moisture, provide essential minerals, and balance the pH of the casing.
