Morel spawn is considered experimental so we do not have a specific preparation we recommend. We do suggest using this experimental spawn in outdoor beds, forest floor inoculations, or using burned substrates. Our morel culture was obtained from fruiting specimens in a burnt pitch pine forest in New England, it could therefore benefit from cultivation trials on burned substrate.
The most thorough description on how to grow morels that we've come across is in Tradd Cotter's book Organic Mushroom Farming and Mycoremediation. He uses a species of morel (Morchella deliciosa) that is less reliant on a symbiotic relationship with trees, however. We look forward to hearing about a specific method for the successful cultivation of the morel spawn we produce!
Morel sawdust spawn will look different from most other spawn you receive. Instead of forming thick white mycelium, it tends to be finer, brown, and forms dense masses called sclerotia. Here is a photo of Morel spawn for reference:
