Mushroom Logistics: Transporting Fungi Safely And Efficiently

Mushrooms are a perishable food item with a short shelf life, so proper handling, cooling, storage, and transportation are critical to maintaining their quality. Mushrooms are easily bruised and discoloured, and they are susceptible to various storage disorders, such as upward bending of caps and opening of the veil. To extend their shelf life, mushrooms are typically transported in temperature-controlled conditions, using specific packaging materials and techniques to prevent moisture loss and control condensation. The legal status of certain mushrooms is also an important consideration when transporting them, as possession and distribution may have serious legal repercussions in some jurisdictions.

Temperature control

To maintain the ideal temperature during transportation, several methods can be employed:

Insulation

Insulating the transport containers can help maintain a stable temperature, minimising heat loss or gain. This is especially important when transporting mushrooms over long distances or in varying climatic conditions.

Cooling Systems

During transportation, cooling systems such as portable air conditioners or evaporative coolers can be used to maintain the desired temperature. These systems are crucial, especially if the ambient temperature is higher than the required 0°C for mushroom storage.

Thermostat-Controlled Cooling

To ensure precise temperature control, transport containers can be equipped with thermostat-controlled cooling systems. These systems allow for accurate temperature adjustments, preventing temperature fluctuations that can compromise mushroom quality.

Monitoring

Regular temperature monitoring during transportation is essential. Transport personnel can use high-quality thermometers or temperature sensors to ensure that the mushrooms remain at the optimal temperature. This proactive approach enables the early detection of any temperature deviations, allowing for prompt corrective actions.

Rapid Cooling Post-Harvest

Immediately after harvesting, mushrooms benefit from rapid cooling to remove field heat. This technique effectively extends the shelf life of mushrooms by slowing down the decay process.

Packaging

Choosing the Right Packaging Material

The type of packaging material plays a significant role in maintaining mushroom quality. Paper-based packaging, such as brown paper bags or cardboard clamshells, is highly recommended. These materials allow mushrooms to "breathe," absorbing excess moisture and regulating temperature. Paper-based packaging also helps prevent bacterial growth, which can occur in plastic bags due to trapped moisture.

Temperature Control

Mushrooms are perishable and sensitive to temperature fluctuations. To maintain freshness, it is essential to control the temperature during transportation. If shipping in warm climates or during hot weather, consider using ice packs placed inside brown paper bags alongside the mushrooms. This helps release cold temperatures into the packaged environment, prolonging mushroom freshness.

In colder months, external temperatures can act as a natural refrigerator, but proper ventilation is crucial. Maintaining temperatures between 50-68 °F (10-20 °C) is ideal for most mushroom strains. If the mushrooms are transported in a vehicle, stabilise the temperature using the AC or heater before loading the mushrooms.

Cushioning and Protection

To prevent damage during transit, adequately cushion the mushrooms inside the box. Old newspaper or paper can be used for padding, providing a protective layer around the mushrooms. Additionally, secure the containers with towels or blankets to buffer temperature changes and minimise movement during transportation.

Transit Timing

Timing is crucial when shipping mushrooms to avoid prolonged transit times that can impact freshness. Shipping carriers are busiest on weekends, leading to delays and inflated rates. Therefore, it is recommended to ship mushrooms only from Monday through Thursday, avoiding Sunday as carriers do not operate on this day.

Legal Considerations

When transporting mushrooms, it is essential to be mindful of legal considerations, especially regarding magic mushrooms. Magic mushrooms are illegal in most parts of the world, including the United States, Canada, and Europe. Transporting them could result in serious legal repercussions, including prison time, fines, or a criminal record. Always be aware of the legal status and potential risks associated with the type of mushrooms being transported.

Legal status

The legal status of psilocybin mushrooms varies worldwide. Psilocybin and psilocin are listed as Schedule I drugs under the United Nations 1971 Convention on Psychotropic Substances, which requires its members to prohibit psilocybin and restrict its use to medical and scientific research under controlled conditions. However, the mushrooms containing the drug were not specifically included in the convention due to pressure from the Mexican government. Many countries have some level of regulation or prohibition of psilocybin mushrooms, such as the US Psychotropic Substances Act, the UK Misuse of Drugs Act 1971, and the Canadian Controlled Drugs and Substances Act.

In some jurisdictions, psilocybe spores are legal to sell and possess as they do not contain psilocybin or psilocin. For example, in the United States, California, Georgia, and Idaho have specifically amended laws to criminalize the possession of psilocybin mushroom spores. On the other hand, Oregon has made "magic mushrooms" legal for mental health treatment in supervised settings. In Canada, the province of Alberta has allowed the use of psilocybin for medicinal purposes in drug-assisted psychotherapy.

In the United States, federal law bans psilocybin and psilocin, classifying them as Schedule I drugs or "hallucinogens" under the Controlled Substances Act. However, some states have decriminalized or legalized psilocybin mushrooms, such as Colorado. In Texas, it is illegal to possess, distribute, carry, use, or grow magic mushrooms, and criminal charges and penalties can be severe.

Transporting magic mushrooms on a plane is generally illegal, even if travelling between places where they are legal. However, contaminant-free microscopic mushroom spores and spore syringes are legal to travel with since they do not contain psilocybin. It is recommended to check the legal status of spores in the areas being travelled to as laws vary by jurisdiction.

Preventing contamination

Firstly, it's important to understand the sources of contamination. Contamination can come from various sources, including the air, cultivation tools, human contact, and even the mushroom cultures themselves. Mould spores, bacteria, and other microorganisms are common contaminants that can ruin a crop. Therefore, it is essential to maintain good hygiene practices and create a sterile environment.

To prevent airborne contamination, you can use a still air box (SAB). An SAB is a large clear container with armholes that allow you to work inside while keeping the contents sterile. This can be effective for small-scale operations. Additionally, improving fresh air exchange (FAE) in your growing environment can help prevent cobweb mould, a common contaminant. You can increase FAE by creating incisions in the plastic of your growing containers or by fanning your growing chambers several times a day.

Proper sterilisation and pasteurisation techniques are critical to preventing contamination. Before inoculating supplemented sawdust fruiting blocks and mushroom grain spawn, they must be completely sterilised using high pressure and temperature for extended periods. A stovetop pressure canner is recommended for this process. If using straw as a bulk substrate, pasteurisation at 65-82°C for at least 90 minutes is sufficient. Incomplete sterilisation or improper pasteurisation is a common cause of contamination.

Personal hygiene is another vital factor in contamination prevention. Before handling mushrooms or working with sterile substrates, ensure your hands are clean, and consider taking a shower to limit the transfer of microorganisms. Additionally, sterilise any tools and equipment that come into contact with the mushrooms or growing environment.

Finally, during transportation, maintain cold conditions to prevent dehydration, spoilage, and bacterial growth. Use coolers with ice packs to keep mushrooms fresh and cold. Ensure the transportation vehicle is clean, and use Standard Operating Procedures (SOPs) to monitor and document temperatures, quality, and cleaning schedules.

Handling

Mushrooms are delicate and perishable, requiring careful handling to maintain their quality and freshness. Here are some key considerations for handling mushrooms:

• Harvesting: Mushrooms, particularly button mushrooms, should be harvested when they reach maturity, which is indicated by well-rounded caps and a fully intact partial veil.
• Packaging: Mushrooms should be packed in trays, cartons, or rigid unit packs with perforated polyethylene film over-wrap. This packaging helps reduce moisture loss and protects the mushrooms from bruising. It is important to avoid water condensation inside the packages.
• Temperature Control: Maintaining low storage temperatures is crucial to slow down the continued development of mushrooms after harvesting. The ideal temperature range for most strains is between 50-68 °F (10-20 °C). Pre-cooling mushrooms before transport is also recommended.
• Humidity: High relative humidity (RH) is essential to prevent desiccation and maintain the glossiness of the mushrooms.
• Ethylene Sensitivity: Mushrooms are sensitive to ethylene, which can cause browning of the caps. Therefore, they should be stored separately from ethylene-producing fruits and vegetables.
• Storage Duration: Mushrooms can be stored for 7 to 9 days at 0°C to 1°C with 95% RH. Storing at 2°C shortens their shelf life to 3 to 5 days due to accelerated surface browning and other changes.
• Controlled Atmosphere (CA): Extended storage of up to 12-15 days is possible using CA with 3% O2 and 10% CO2 at 0°C. Elevated CO2 levels help prevent decay and reduce blackening of the stipe and gills. However, improper control of CA or packaging can lead to oxygen depletion and favour decay.
• Storage Disorders: Common issues during storage include upward bending of caps and opening of the veil. Proper temperature and humidity control help prevent these issues.

Transport

When transporting mushrooms, it is essential to maintain the optimal conditions mentioned above to ensure their freshness and quality upon arrival. Here are some additional considerations for transport:

• Vehicle Preparation: Clean the vehicle thoroughly, including vacuuming and disinfecting, to reduce the introduction of foreign matter or potential contaminants.
• Container Security: Secure the mushroom containers snugly in the vehicle's trunk or a designated transport cabinet to prevent sliding and movement during transport. Use padding, towels, or blankets to stabilise the containers or strap them down with cords.
• Temperature Management: Ensure the vehicle's temperature is stable and within the ideal range before loading the mushrooms. Use the AC or heater to achieve the desired temperature, and cover containers for additional temperature buffering.
• Air Circulation: For long-distance transport, open the containers periodically (every 5-6 hours) to allow fresh air circulation and spray with water to maintain moisture.
• Legal Considerations: Be aware of the legal status of the mushrooms you are transporting, especially if they are classified as magic mushrooms, as there may be legal repercussions in certain regions.

Frequently asked questions