Grow Oyster Mushrooms At Home: Frugal Gourmet

Oyster mushrooms, yum, such a delicious gourmet food, yet sold at $40 to $50 per kilo.

Grow your own oyster mushrooms at home for a fraction of the price of buying. Be gourmet, without the excessive price tag. Plus, these mushrooms will be as fresh as you can get them.

Why oyster mushrooms? These are the easiest of the gourmet ‘tree species’ of mushroom to grow. In the wild they grow on rotting tree stumps. At home, you can grow them in paper kitty litter, yes, that’s right, kitty litter.

Oyster mushrooms come in many colours and have varieties suited to different climate temperatures. Variations in colour include white, yellow, grey, blue and pink.

Oyster mushroom grow in a variety of colours

Did you know: Experts recommended eating mushrooms cooked to get the best nutritional benefit from them. In the raw form, mushrooms are indigestible. Whilst you can safely eat a raw mushroom, you won’t get any nutrition from them.

Mushroom Spawn

To grow mushrooms you will need to purchase spawn.

Mushroom spawn is the mycelium, or vegetative growth, of the plant. Consider it similar to an apple tree. The mycelium is the tree, and the mushroom is the fruit.

Mycelium and the resulting mushroom
Mycelium and the resulting mushroom: from Yellow Elanor

Spawn can be purchased easily online and posted to your home. At first glance, the price of spawn can look very pricey. However, a $45 bag weighing 2.2kg will grow you a lot of mushrooms if you use the process below.

For each 100g of purchased spawn, you’ll be able to create a 2kg ‘fruiting’ block. This is because 100g of spawn will colonise 2kg of substrate (kitty litter) then go on to producing mushrooms.

Each block/bag weighing 2kg has the potential to have a 100% harvest rate per weight. For example, one 2kg bag may end up producing 2kg of mushrooms.

If you’re now having nightmares about having 22 bags each weighing 2kg scattered around your house, never fear. Mushroom spawn can be kept dormant, essentially asleep, in your fridge. Simply remove 100g when needed.

If you are in Australia, Aussie Mushroom Supplies have a great selection of spawn available to purchase. I’m very much looking forward to purchasing their pink oyster mushroom spawn once the weather warms up.


Oyster mushroom spawn, suited to your climate temperature

Paper kitty litter with no additives

Wheat or Oat Bran

Gloves: rubber reusable gloves or, if no choice, disposable food grade plastic gloves

Hydrated (brickies) lime, can be purchased at places such as Bunnings

Container to store 2kg substrate: for example, food grade unused paint tins, large ice-cream containers, or if no choice, large plastic snap lock bags

Micropore tape, allows the spawn to breathe whilst stopping other moulds getting into the wet substrate. For sale at pharmacies.

Bucket for mixing; I prefer stainless steel over plastic

Measuring cup, for the water

Teaspoon, to measure out the hydrated lime

Scales, for weighing out the kitty litter and the spawn

Water spray bottle



The first step is make sure everything is clean. Mushroom mycelium is essentially a mould and you need to be careful not to inadvertently introduce a competing mould.

In a commercial setting everything is sterilised. At home, ensure your table, gloves, containers, scales – everything that will come into contact with mushroom growing is clean.

I’ve lost three 2kg buckets of mushroom spawn due to contamination by a green mould inadvertently introduced. Now I’m so much more careful about cleanliness.


The substrate is the base the mycelium grows and feeds on. For these instructions on growing oyster mushrooms we use paper pellets, also known as kitty litter.

Bag of paper kitty litter made from recycled paper

To create a 2kg bag of substrate, you’ll need:

  • 800g paper pellets
  • 1.2L water, with a teaspoon of hydrated lime
  • 100g spawn

Pour the water into a bucket and add one teaspoon of hydrated lime, stir.

Put the paper pellets into the bucket and mix with the lime water, using your gloved hands, until all the pellets are wet and are breaking down.

Crumble 100g of spawn into the bucket of wet substrate and thoroughly combine.

Congratulations, you have now inoculated the substrate!


Place your 2kg of inoculated substrate into a container with breathing holes.

Personally, I’ve used both food grade paint tins and 4L ice cream containers with 1cm holes drilled into them.

You could also use cleaned paper milk cartons or large snap lock bags.

Any container you use will need a lid or be able to be sealed up. The container will also need ‘breathing’ holes for the mycelium to be able to take in oxygen.

Each breathing hole will need to be covered with micropore tape, just a small amount to cover the hole and no more. The reason for this is the mushrooms grow out of the breathing holes and push the tape off as they grow.

Keep your inoculated substrate away from direct sunlight and within the recommended growing temperatures.

Feeding the Mushroom Spawn

After 7 days you will need to feed the spawn in the inoculated substrate.

In a clean bucket add 100ml water with 1 teaspoon of hydrated lime, stir. Add 100g wheat or oat bran and mix well.

Brand name wheat bran is cheap and does the job

Wearing gloves, break up and crumble your 2kg of inoculated substrate into the bucket with wet bran. Combine thoroughly.

Return the now fed inoculated substrate back into the container it came from.

Mushroom Harvest

Once the substrate has become a solid white block, it is ready to fruit.

Fully inoculated block, note the mushrooms forming in the corner

The oyster mushrooms will push the tape away from the breathing holes and from then it’s 5 – 10 days until harvest.

After the mushrooms first appear out of the breathing hole, lightly spray them with water a few times a day.

Grey oyster mushrooms at the ‘pinning’ stage

Oyster mushrooms are ready to harvest when the edge of the caps go from curled to flattened out. Harvest all the mushrooms from that container at the same time even if some have flattened out and others have not. This is because once one cluster is harvested the rest stop growing.

Oyster mushrooms ready to harvest

You remove the mushroom cluster by grabbing at the base and twisting and pulling. It’s important to weigh the clusters as later on you’ll need to replace the weight of the mushrooms with water back into the substrate.

The first harvest is called the ‘first flush’.

Repeated Flushes

After first flush, prepare for the next flush by re-feeding the spawn from the recently harvested container.

As with before:

In a clean bucket add 100ml water with 1 teaspoon of hydrated lime, stir. Add 100g bran and mix well.

Wearing gloves, break up and crumble your 2kg of inoculated substrate into the bucket with wet bran. Remove any contaminated areas (they will look green) and discard.

Add the weight of the mushrooms harvested back into the substrate as hydrated lime water. For example, if 220g of mushrooms were harvested, add back in 220ml of lime water.

Thoroughly combine the bran, inoculated substrate and water.

Place back into the original container. Re-taping any breathing holes with micropore tape as needed.

After each flush, continue the flush re-feeding procedure until the block either stops producing or you lose it to contamination.

Happy Shrooming!

Interested in foraging for wild mushrooms? Read about Saffron Milk Caps!

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