How To Grow Oyster Mushrooms: The Ultimate Step By Step Guide

 How To Grow Oyster Mushrooms At Home

Step 1: Get Prepared

First, you’ll need to decide what type of oyster mushroom you want to grow. 

There are several different types of oyster mushrooms from which to choose. Here are some of the more popular ones.

• Pearl oyster mushroom (Pleurotus ostreatus)

Sometimes called the common oyster mushroom, winter oyster mushroom, or grey oyster mushroom. 

The pearl oyster mushroom is one of the most commonly available varieties. They grow best in colder temperatures.

• Blue oyster mushroom (Pleurotus ostreatus var. columbinus)

Commonly found throughout the northern hemisphere, the blue oyster mushroom is a sub-species of the common oyster. 

It’s one of the fastest colonizers of all the oyster mushroom varieties and prefers growing in cooler temperatures of 45-65 F (12-18 C).

• Phoenix oyster mushroom (Pleurotus pulmonarius)

Also sometimes known as the summer oyster mushroom, Italian oyster mushroom, or the Indian oyster mushroom, the phoenix oyster mushroom has evolved to grow in warmer climates. 

Depending on the strain, it is either white or a brown/tan color.

• Golden oyster mushroom  (Pleurotus citrinopileatus) 

Sometimes also called yellow oyster mushrooms, this variety is best known for its amazing color, and for looking similar to the popular chanterelle mushroom. 

They prefer warmer temperatures of 64-86F (18C-30C).

• Pink oyster mushroom (Pleurotus djamor)

One of the most striking of the oyster mushroom varieties, the pink oyster mushroom grows quickly, producing fruits in as little as 3-4 weeks. 

They prefer warmer temperatures of 64-86F (18C-30C) .

• King oyster mushroom  (Pleurotus eryngii)   

Also known as the eryngii mushroom, it has a firm texture and delicious meaty flavor. 

It is more difficult to cultivate than other oyster mushrooms. So it’s not the best variety to get started with. It prefers cooler temperatures between 45-65 F (12C-18C).

Decide Which Oyster Mushroom Substrate To Grow On 

Substrates are the food source which enables the growth of mushroom mycelium.

Mycelium is the root-like vegetative growth of the fungus and is critical to the cultivation of oyster mushrooms in the same way an apple tree is to an apple.

The most widely used substrate for oyster mushrooms is straw. However, sawdust, cardboard, coffee grounds and other byproducts of agriculture such as sugarcane bagasse, coco coir and cotton waste can also be used.

How do you decide which substrate to use? Choose whichever is the easiest for you to source!

The easiest substrate to get started with is probably wood pellets as they come already pasteurized and you just need to add water to hydrate them. 

Straw is also a very forgiving substrate to grow on.

Either way, choose a substrate material that you can easily source and use the instructions below to prepare it for inoculation.

-> If you want to skip the learning curve of making your own substrate, you could also consider buying ready-to-fruit Oyster mushroom blocks, which come fully colonised and ready to grow.

Order Your Supplies

Before you get started on the growing, the last step is getting your supplies ready so you can get started.

You’ll need to order:

1.  Oyster mushroom spawn (at least 100g, but preferably 1kg or more)
2. Your substrate material 
3. Either make or purchase growing bags/containers

If you’re UK based, you can buy oyster mushroom spawn from our shop. 

Outside the UK, the best thing is to just do a search for “oyster mushroom spawn + [your country]”.

In most countries there are a number of suppliers. You can often pick up spawn like this on Amazon or Ebay as well. 

Grain spawn will produce bigger yields than sawdust spawn, so try to source this if you can. 

Oyster mushroom grain spawn

As for growing containers, ideally you’ll get hold of purpose made mushroom cultivation bags. They enable the perfect air exchange and keep out competing molds and bacteria.

Unicorn 10T mushroom cultivation bags with breathable filter patch

If you can’t source these growing bags, you can also grow mushrooms in a bucket, like this, or use large freezer or Ziploc bags with 0.5mm holes poked in every 10 cm around the bag.

Step 2: Prepare Your Oyster Mushroom Substrate

The goal of the substrate is to provide a hydrated nutrient-dense food source which is also devoid of other micro-organisms that would normally compete with the mushroom mycelium. 

Straw, cardboard, sawdust pellets and coffee grounds are all easy substrates to use for growing oyster mushrooms that achieve this goal.

Here’s a quick overview of how to prepare each one.

Straw and Cardboard

Straw is the most commonly used substrate for oyster mushroom cultivation. It is usually cheap, contains essential nutrients and oyster mushrooms thrive on it.

Pasteurize by soaking in hot water (65-80C / 149-176 F) for 1-2 hrs, or in a cold water high-pH lime bath for 12-18 hours. 

Sawdust Pellets

The great thing about using these is that they are already pasteurized by the heat and pressure of pellet production process. 

Add equal weight of water to weight of pellets, soak for 30 mins. And then mix to break up the pellets into hydrated sawdust.

Coffee Grounds

Waste coffee grounds are a plentiful (and already pasteurized) resource.

Despite a lot of misinformation on the internet, coffee grounds can actually be a pretty good substrate for growing oyster mushrooms.

The key is to only use fresh grounds (within 24 hours of brewing) which are already pasteurized and hydrated by the coffee brewing process. 

Beyond 24 hours, competing molds start to develop and will outcompete your mycelium.

Ideal as a substrate on it’s own in small amounts (1kg or less), but if you go bigger, mix in 20-50% of straw.

Check out our article about how to grow mushrooms on coffee grounds for more info.

Step 3: Inoculation

Inoculation is the process of adding your mushroom spawn to your prepared substrate.

Before you start mixing, clean your hands well with soap and wipe down all surfaces you’re about to work on with a cleaning spray.  

Make sure your substrate has the right moisture content. The pasteurization process will probably moisten your substrate to the correct level, but it’s essential to check that your substrate is not too dry or too wet.

Depending on the material, you are aiming for anything between 55% hydration (sawdust and coffee grounds) to 74% (straw). The easiest way to check is with the squeeze test.

Squeeze the substrate slightly in your hand. It should bind into a ball in your hand, and a couple drops of water should come out. If more than this occurs, you’ll need to dry your substrate out a bit. If it doesn’t hold together in your hand, it is likely too dry, and you’ll need to add more water.

Next, mix the substrate and mushroom spawn in a container of some sort (large plastic box, barrel, whatever you have to hand) then load the substrate into your growing vessels and close the top with a rubber band, paperclip, tape or tie of some kind.

If you’re not using a filter patch bag, then make a few tiny holes every 10cms around the bag for air exchange. Check out this short video lesson where we walk you through an example of the inoculation process with coffee and straw as the substrate