Mushroom Growing 101: The Casing Tek, Using a Casing Layer.


Growing mushrooms at home, can be an easy a fun project. Although patience and sterile techniques are the keys to success in any mycology project. There are simple ways to get started before diving into the more advanced methods. The casing tek is a great place to start.

Growing mushrooms with a casing layer is a simple yet effective technique that can significantly increase your mushroom yields. Here, we will walk you through the process of casing your mushroom kit and discuss the importance of using the right casing materials.

The casing technique in mushroom cultivation involves creating a layer of material on top of the substrate where the mycelium is growing.This layer helps to provide moisture and nutrients to the developing mushrooms, as well as creating a protective barrier to prevent contamination.

There are many different materials that can be used for casing, such as peat moss, vermiculite, coconut coir, or even just a layer of sterilized soil. The choice of casing material will depend on the specific needs of the mushroom species being grown and the preferences of the grower.

The casing technique is particularly useful for species that require higher humidity levels or have specific environmental requirements. By creating a suitable microclimate within the casing layer, growers can ensure optimal conditions for fruiting and maximize their yields.

Overall, the casing technique is a valuable tool in the arsenal of any mushroom grower, helping to promote healthy mushroom development and improve overall crop success. With a little practice and experimentation, growers can master the art of casing and take their mushroom cultivation to the next level.



So, what exactly is the casing technique? Well, it involves creating a conducive environment for mushroom growth by providing a layer of nutrient-rich material on top of your mushroom substrate. This layer of material, known as the casing layer, helps retain moisture and provides additional nutrients for the growing mushrooms. retaining high humidity levels across the surface where mushroom pins with begin to grow.


Now, you might be wondering, how do you prepare the casing layer? Don’t worry, it’s a piece of cake! One simple recipe for a casing layer involves mixing peat moss, vermiculite, and a bit of limestone. This mixture helps create the ideal conditions for your mushroom pins for form. The word pins comes from mushroom Primidoria, these are essentially, the start of baby shrooms.

Mushrooms pinning on a cased substrate.


To create a simple casing layer:

Step 1. Begin by mixing equal parts 50% Vermiculite and 50% peat moss together. The amount of each you will need will depend on the surface area of the mushroom mycelium you are trying to cover. You will want it about a half inch deep over the substrate.

Casing layer recipe.
Peat and vermiculite mix.



Step 2.  You will need to Pasteurize the casing layer at around 60c-80c (140f-176f) for 1 hour.

This can be achieved by placing the mixture in a pillow case. Boil a large pot of water. Once boiling turn the pot off. Fully submerge the pillowcase, cover and let sit for the hour. Then drain and let the bag completely cool back to room temperature before applying to your substrate.


Once you have your casing layer ready, it’s time to apply it to your mushroom substrate. This can be directly to grain or a bulk substrate you have previously spawned your grain to. Make sure your substrate is fully colonized by mycelium. Then Gently squeeze any excess moisture from the soil. there should only be a drop or two that falls when squeezed in your hand. This is know as field capacity. Use gloves to keep any contaminants out of your casing mix. Then spread the casing layer evenly across the substrate, making sure to cover it completely.


Casing the substrate.
A substrate halfway cased.

Fruiting with the casing tek.

Now comes the crucial part – maintaining the right environment. Mushrooms are quite sensitive beings, and they need a specific set of conditions to thrive. The ideal temperature for mushroom growth depends on the species. For edibles such as blue oyster, it usually ranges from 65 to 75 degrees Fahrenheit. But for magic mushrooms like Psilocybe Cubensis, you will need higher temperatures, between 75-84 F.

Additionally, mushrooms also require high humidity levels, preferably around 80 to 95 percent.


To ensure the right temperature and humidity, you might need to invest in some equipment like a heater or a humidifier. You can also cover your mushroom growing area with a plastic sheet or use a small greenhouse to create a mini mushroom paradise. Just remember to monitor the environment regularly and make adjustments as necessary.


Continue to keep your newly cased substrate in the dark, anywhere from 3-10 days. Until you see mycelium is growing through the casing layer.

Benefits of Using a Casing Layer

Increased Moisture Retention

  • Retains moisture for optimal mushroom growth
  • Helps prevent drying out of the substrate
  • Promotes healthy and robust mushrooms

Enhanced Nutrient Absorption

  • Provides additional nutrients for the mushrooms
  • Improves overall mushroom development
  • Boosts the nutritional value of the harvest

Choosing the Right Casing Materials

Peat Moss

  • Retains moisture well
  • Supports healthy mycelium growth
  • Easy to find and affordable


  • Provides good aeration
  • Enhances water retention
  • Helps maintain optimal humidity levels


  • Sustainable and eco-friendly option
  • Resistant to Contamination
  • Supports healthy mushroom growth

Applying the Mushroom Casing

Prepare Your Casing Layer

  • Mix casing materials in the right proportions
  • Sterilize casing to prevent contamination
  • Ensure proper moisture content for ideal growth conditions

Apply Casing to Your Mushroom Kit

  • Evenly distribute casing layer over the substrate
  • Gently pat down the casing to ensure proper coverage
  • Mist the casing layer lightly to maintain moisture levels


Monotub pinning.Now, all that’s left to do is wait patiently. Mushroom growing is a slow and steady process, so don’t expect overnight miracles. It usually takes a few weeks for mushrooms to start sprouting, and even then, they will continue to grow and develop over time. During the growing process, be sure to keep the casing layer moist by misting it with water every few days. This helps prevent the mushrooms from drying out and ensures they have the moisture they need to grow and mature.




Once your mushrooms reach their desired size, it’s time for the harvest! Carefully pluck them from the casing layer, making sure not to damage the surrounding mycelium. Remember, mushrooms are delicate creatures, so handle them with care.


And just like that, you have successfully grown your own mushrooms using the casing technique!