Introduction

This technique can be used to grow mushrooms in an indoor or outdoor setting. It’s an easy way to scale up grain spawn without having to use a pressure cooker. There are no special tools required (except a drill bit). The instructions below use sawdust pellets as the substrate inoculated with grain spawn but you could swap those out for hard wood chips, hard wood shavings or straw for the substrate with sawdust spawn. This method is ideal for oyster mushrooms except for king oysters. See the ‘Variation’ section below the instructions for how to prepare wood chips and straw if you decide to go that route!

When and where to make the buckets

• If you are keeping the buckets indoors, you can create them at any time of the year
• If you are doing these buckets outdoors, then you need to create them in the late spring and summer. The mycelium does not grow in winter temperatures although it can survive being frozen on sawdust

Equipment

• Grain spawn (oyster variety) – available to order on our store
• Sawdust pellets (hardwood fuel pellets)
• Water
• Bucket with drilled holes (1 – 3 gallon, food grade)
• Boot tray or something to place the bucket on to catch extra moisture
• Plastic bag to cover the top
• Masking tape

Method

Step 1: Create buckets

• We drill 1″ holes in buckets.  Typically 3 holes per side.  These buckets shown are slightly smaller than regular 5 gallon buckets.  Any bucket between 1- 3 gallons will work. You should make sure that the bucket is food grade and has not had anything like oil stored in it.  However, you can see that sometimes we don’t follow our own rules…
• Cover the side holes with masking tape. Leave the bottom holes open to allow extra water to escape

Step 2: Hydrate sawdust pellets

• Mix sawdust pellets and water in a container with no holes. When you are using cold water, it takes a while for the pellets to hydrate. Be patient
  • We cannot stress this enough. You need to use HARDWOOD pellets (You can buy bags of pellets from Canadian Tire)
  • Hardwood pellets work with this technique because they are very clean. There is low risk of contamination
• We don’t have exact measurements for water and pellets – but you will need a full bucket of hydrated sawdust.  It can’t be too wet.  When you squeeze a handful of it, a bit of water can come out but no more

Step 3: Layer grain spawn and sawdust

• Start with a layer of sawdust at the bottom.  Make it about 3″ deep each time
• Add a layer of grain spawn
• Add another layer of sawdust
• Add a layer of grain spawn…
• Continue until the bucket is above the last hole that you drilled
• The last layer should be a thin layer of sawdust spawn
• For this bucket, we used about 5 cups of grain spawn or 1 kg

Step 4: Maintenance, overwintering and harvest

• Cover the bucket with a plastic bag (opaque) until the bucket is fully colonized
• Make sure, especially if the bucket is inside, that you place it on a boot tray or something else to catch moisture
• Check every 3 days or so to see how it is doing
• Use the masking tape to take a “peak” at how far the mycelium has colonized – you will see it turn white!
• Once the mycelium has fully colonized the bucket, take off the masking tape and the plastic bag
• These buckets will probably survive being frozen but would need a new food source in the spring

Variation

• Some people find that sawdust in a large (bucket 4-5 gallons) gets to be too dense making it hard for the mycelium to breath, if you find this you can mix your sawdust with wood shavings or straw if you are using a larger bucket. See below for how to prepare wood shavings and straw.
• Wood chip variation: ideally the wood chips should be from a healthy hard wood tree (like Aspen) that has been harvested in late winter/early spring before the leaves bud out and used within 6-8 weeks. 
• Wood shaving variation: should be from a hard wood tree (can often find them as bedding at pet stores). You need to pasteurize the wood chips by putting them in a large tote and covering them with boiling water then cover with a lid and let sit for 8-12 hours. Then drain and use immediately.
• Straw variation: use chemical free straw (definitely without fungicide!) and chop it into pieces ~3-4 inches (could use a weed wacker in a metal barrel to do so or simply large gardening shiers). The pasturize your straw in hot water for 90 minutes. The water needs to remain between 70 -85C the entire 90 minutes so use a thermometer to monitor it. Then drain the straw and let it cool for 30 minutes (if too hot will kill the mycelium) and use immediately. 
• You can also create these buckets with sawdust spawn
• After the bucket is colonized, you can add it to a garden bed. It’s an easy way to create more spawn quickly

Fungi Akuafo Experience

• These buckets are easy to make and typically quite successful
• Expect to get contamination sometimes – ensure you get rid of the contaminated sawdust before the contamination moves to other healthy buckets
• We get fruits in these buckets within 2 weeks
• You can stack these buckets so that there is not such a large surface area on the top of the bucket for fruits – this will help you get better results
• We like that the buckets are reusable – ensure you clean them very well before using them again

Books

• Growing Gourmet and Medicinal Mushrooms by Paul Stamets
• Radical Mycology by Peter McCoy