How to use the different types of mushroom substrates (2024)

Growing mushrooms has become quite the trend, thanks to their potential as a food source and their use in various culinary and medicinal realms. This is the foundation for mushroom growth, playing an essential role in providing the nutrients, moisture, and oxygen needed for optimal mycelium development. Check out all about different mushroom substrates and how to use them here.

Mushroom Substrate – What’s that?

When we talk about a mushroom substrate, we’re referring to the physical medium in which they are cultivated. Indeed, it’s where spores germinate, and consequently, mycelium grows, leading to the appearance of fruiting bodies.

This is a critical factor in growing mushrooms as it provides the nutrients, water, and oxygen that mycelium cells need to thrive. On the flip side, the chosen substrate type can affect the taste, aroma, and texture of the mushrooms themselves.

Types of mushroom substrates

Choosing the right substrate is crucial for mushroom cultivation, as it directly impacts the health and productivity of the mycelium. There are two main types used in mushroom cultivation: natural and synthetic, each with specific characteristics influencing development.

Natural substrate

Natural substrates consist of organic materials and are ideal for those seeking a more organic and sustainable production with a lower cost. Some examples include:

• Cereal straw: Used for its accessibility and good performance.
• Compost: A mix of organic matter that promotes mushroom growth.
• Wood: Suitable for certain types of mushrooms that grow on trees.

Synthetic substrate

In contrast, synthetic mushroom substrates are designed to offer a more controlled and sterile environment for mushroom cultivation. These substrates often include components like coconut fiber and vermiculite, facilitating handling and reducing the risk of contamination. They’re suitable for growers looking for consistency and control in their mushroom production.

Best mushrooms substrates

When choosing the best substrates for magic mushrooms, consider factors such as:

• Nutritional content: Ensure they contain all the organic nutrients needed for mushroom growth.
• Texture and porosity: Adequate for aeration and moisture retention.
• Absence of contaminants: Essential to avoid competition with other organisms.

Beyond these characteristics, they should also be easy to prepare and budget-friendly. Some popular choices among growers include:

Coconut fiber and vermiculite mix

Excellent mushroom substrates, with a typical ratio of 1:1. Pasteurizing the mix before introducing spores is recommended.

Coco fiber and vermiculite

Mixtures of coconut fiber and vermiculite make excellent mushroom substrates. Coconut fiber is obtained from the husk of this fruit, while vermiculite is a heat-expanded mineral with high water retention. Typically, a standard mixture of coconut fiber and vermiculite consists of a 1:1 ratio. Before introducing the spores, it is recommended to pasteurize the mixture.

Manure

Manure is a valued substrate for many mushroom species, such as Psilocybe. However, its use in home cultivation can be complicated, as it needs to undergo a composting and pasteurization process to eliminate unwanted microorganisms. While common in commercial crops, manure may not be the most practical option for domestic use.

Coffee Grounds

Coffee grounds are recognized for their high nitrogen content, serving as excellent soil enhancers and also usable as a mushroom substrates growing. However, it is advisable not to use them as the sole option due to their high concentration of organic compounds, which can easily contaminate the cultivation. The best practice is to add them to other substrates, such as coconut fiber or sawdust, and sterilize or pasteurize them beforehand.

Soybean hulls and sawdust

Soybean hulls are another suitable substrate for mushroom cultivation, especially when mixed with sawdust. The ideal ratio may vary depending on the type of mushrooms being cultivated, starting with a 1:1 ratio and gradually increasing until finding the one that provides the best results.

On the other hand, sawdust, typically derived from trees like oak or maple, is a widely used substrate, usually combined with wood chips to improve its structure and colonization rate. The use of softwoods is not recommended for magic mushroom cultivation. Alternatively, wood pellets, previously soaked in water and decomposed into sawdust before inoculation, can be employed.

Straw

Finally, straw is a high-quality substrate for mushroom cultivation. Although it may require some effort, such as cutting, cleaning, and pasteurizing, its affordability makes it an attractive option, especially for home cultivators. Simply pasteurize it before use.

Other Mushroom Substrates

If preferred, ready-made mushroom substrates are available at affordable prices. These usually consist of rye, vermiculite, perlite, or gypsum, aiming to retain moisture and provide a suitable structure for mycelium development. These are much easier to use.

How to prepare mushroom substrates

Proper substrate preparation is crucial for success in mushroom cultivation, involving two key methods: sterilization and pasteurization, both designed to make the substrate suitable for mycelium growth by eliminating competing organisms.

Sterilizing mushroom substrates

Sterilization involves the complete removal of all microorganisms in the substrate. It’s commonly done using a pressure cooker that reaches temperatures exceeding 120°C, ensuring the substrate is free from contaminants. This step is essential, especially when working with grain-based substrates susceptible to contamination.

Pasteurizing mushroom substrates

In comparison, pasteurization reduces but doesn’t completely eliminate the organisms present in the substrate. This method is carried out at temperatures between 65°C and 85°C, sufficient to kill harmful organisms while allowing beneficial microorganisms to survive. Pasteurization can be done with a hot water or steam bath.

Control and storage

Proper maintenance is crucial to ensure successful final results, as well as correct substrate storage.

Humidity and temperature control

Humidity is vital in mushroom cultivation, and it should be maintained at levels of 85% to 95% to promote mycelium growth. In addition, it is recommended to spray the substrate with water daily and check humidity with a hygrometer.

The optimal temperature for cultivation varies by mushroom type, but generally falls between 18°C and 24°C. In fact, adjustments in the growing room can be made using fans or heaters as needed.

Contaminant control

Contaminant control is essential in the magic mushroom cultivation process. That’s why a sterile environment must be maintained during substrate preparation and handling, as the presence of pathogens can affect mushroom development or even destroy the harvest. Cleaning and disinfecting work surfaces and equipment before use are recommended. Moreover, a good practice is to use gloves and masks to minimize the introduction of contaminants to the substrate.

Storage conditions

For the storage of magic mushrooms, it’s crucial to keep them in a cool, dark place with low humidity to preserve their potency and prevent mold growth. A common method is to use paper bags or airtight containers, providing a dry environment and limiting oxygen exposure. Temperature also plays a significant role: mushrooms should be stored in a temperature range of 2°C to 4°C to optimize preservation.

Mushroom substrates are a good choice for mushroom enthusiasts, allowing experimentation with different substrate types until finding the right one.