What should I check about a specialty mushroom grower’s contamination history?

Ask the seller to walk through their worst contamination event. What was noticed first, how quickly was it caught, what was done with affected material and how long did the room sit idle? Ask whether the cause was ever found, whether it recurred and whether any customers were affected.

Ask for the batch records behind each event. Compare loss rates across rooms and species, and across the seasons. A pattern in one room may point to air handling or a particular crew practice. Ask where spawn comes from and how it is checked on arrival, since a problem can enter with an input.

Look at hygiene on the floor: footwear and clothing changes, tool cleaning, door and airlock habits, and how waste is moved out. Ask what is cleaned between cycles and how the seller knows it worked. A supplier plan helps too, since a single spawn source is a single point of failure. Ask whether the seller has a working relationship with an outside lab or adviser. Your lawyer can ask the seller to disclose known issues in the agreement. Ask what the seller would fix first with more money, since the answer often points at the weak spot. Ask also how they decide when a room should be shut down and cleaned.

Key takeaways

• Ask for a written history of lost batches and their causes.
• Compare loss patterns across rooms, species and seasons.
• Watch the hygiene routines in person.