This Guy Grew Oyster Mushroom In His Home Kitchen. Here’s How You Can Too…

While surfing the internet recently, we came upon a local blog that seems to share some helpful information. Though they have not posted much content recently, there was one particular post that stood out to us:

How I grew oyster mushroom in my home kitchen

In the post the author seeks to share how he has managed to grow (and eat) his own home-grown mushrooms, right here in Zimbabwe. The tips he shares are rather helpful and we thought it best to share the article (with their permission) with our readers.

Mushroom is an amazingly tasty and certainly healthy delicacy for many Zimbabweans. Even at US$1.00 per 200g it’s still over priced for many households to enjoy without limits in the current economic climate.

In my research and talking to seasoned mushroom farmers I discovered that Zimbabwe’s total mushroom production is still very low compared to the potential demand. This is also one of the reasons why big chain supermarkets tend to import some particularly during the summer season when its more challenging to successfully grow it locally due to high temperatures and low humidity (more on this later).

A few months ago I began going through hours of Youtube videos in an attempt to teach myself more about mushroom growing and oyster mushroom in particular. In fact, oyster mushroom is the easiest to grow for beginners and at a low cost compared to say button mushroom. In Zimbabwe, virtually all farmers specialize in oyster varieties and white button mushroom.

I had the option to enroll for a US$50.00 mushroom growing class but being a techie my goal was to really immerse myself in the process using tools I’m used to – online video – and learn from other simpletons like me from around the world.

In so many places I found people succeeding in growing oyster mushroom from home for their own consumption using very simple methods. So my journey began.


This is where I spent a lot of time experimenting and failing before succeeding. Substrate is the medium in which your mushroom will grow. It can be grass, wheat straw, leaves, cotton hull and so on. In fact there are more than a hundred substrate options to use when growing oyster mushroom.

Which substrate you finally settle for matters for two main reasons, I found. It determines your yield and it also increases or reduces risk of contamination and these are extremely important factors. You also want to think about cost and availability of the substrate or the growing medium as it were.

So taking all these factors into consideration I settled for simple peanut shells. I particularly liked these shells not only because they are available in abundance but also because as you can see they are not solid shells but slightly crushed which is great for moisture retention. We will talk about some of this later below.


Oyster mushroom growing is complicated (yet still simple) by contamination. When you mix your mushroom “seed” (known as spawn) into the substrate – in my case peanut shells – a living fungi called Mycelium begins to grow out of the “seed” colonising the entire substrate in the form of a network of fine white filaments until it turns the substrate into a white or creamy yellowish outlook.

In order for this to happen, your substrate must be free of any competing fungi found in nature and inherently in your chosen substrate. This is why substrate MUST be pasteurized. If this is not done, contamination in the form of some green or dark looking stuff will appear within a few days of inoculating your substrate (mixing spawn or seed with your substrate for colonisation). Once this happens, your project is failed and you have to throw it away.

The way I did my pasteurization was simple. I heated some water to 80 degrees Celsius and then took an old but clean pillow case which I filled with my chosen substrate (peanut shells). Tying the open end, I put the peanut shells filled pillow case in a bucket and carefully poured the hot water to completely cover the pillow case. The bucket was sealed on top and let to sit for up to 1 hr 45 minutes.

This is the pasteurisation process which kills any unwanted fungi and competing micro-organisms that would definitely contaminate the substrate. The reason why we don’t boil to 100 degrees Celsius is because we don’t want to kill other organisms that actually work in favor of our mushroom production.

After the set sitting time, I lifted the pillow case from inside the bucket and drained the peanut shells of excess water by just hanging the pillow case out on a tree. The goal here was to leave the substrate with only traces of moisture and not running water. I then emptied the shells from the pillow case into a separate CLEAN bucket closed it and set aside to cool.


Inoculation simply refers to the process of introducing your spawn or mushroom seed into the substrate. In my case I bought the spawn elsewhere for this purpose. I wasn’t successful at making my own spawn as some people I saw in videos doing, as this, I concluded, is a highly scientific process requiring facilities of the most hygiene level.

In fact, proper spawn producers do it in specialised labs. The whole process of attempting, which I don’t regret, however gave me invaluable insight into the mechanics of oyster mushroom production.

Moving on, I took a clean empty plastic bag which I ran the sides whilst flat with tiny holes the size of the head of a needle to allow some bits of air in. Then I began the process of laying layer by layer of substrate and spawn until the bag was filled, sealing it at the top. All the time I ensured hygienic conditions to reduce the risk of contamination which remains present until the bag is sealed.


zimbabwe oyster mushroom growing

Once my bag was filled with both substrate and spawn (inoculated), it was time to enter the incubation period. I had prepared a dark room which can be your pantry, under your kitchen or bathroom sink or even a closed but aerated box. In my case I used a pantry for this purpose ensuring there was clean air and a very clean but dark environment.

Mycelium (mushroom fungi) requires oxygen and gives out carbon dioxide, so it is necessary to keep the air exchange good (hence those tiny pin holes on the sides of the bag I mentioned above) and a generally clean airy environment.

Now this is important and boils down to substrate used. Most tutorials and materials say your incubation period will be as many as 21 days. In my case, the peanut shells were completely covered or colonised by mycelium in 10 days. It appears the mycelium just loved to consume the peanut shells so this was great. Even though completely colonised, I allowed a few more days in the dark room before moving the bag out for fruiting.


This is perhaps the most exciting time in your home mushroom farming stages. Your bag is fully colonised and now its time to get the mushrooms growing. What causes mushroom to start growing is the introduction of light, humidity and oxygen. The way I did this was by cutting open sides of my bag to allow more oxygen to enter.

My experimental farming was taking place in November 2015 when the temperatures were still high and humidity very low due to delayed rains. So I created a humidity tent which is essentially a plastic bag with holes which I covered my colonised mushroom kit with as shown below. I would spray it inside with water some three to four times per day to achieve about 75% humidity. Mushroom does very well at 90% to 100% humidity even though 60% humidity will work as in my experience.

I also endevoured to keep the bag in an environment not exceeding 23 degrees Celsius even though this was extremely hard to achieve during the days of the heatwave as many may remember. Oyster mushroom yield and quality is influenced by all these factors.

mushroom growing zimbabwe

This is my humidity tent…just an inverted plastic bag with a few holes to create a natural environment with a lot of water in the air. You can also see a device inside tracking my humidity and temperature levels.

Fruiting refers to the actual pooping out of what are called pins on the surface of the bag. Once these pins appear they grow dramatically within pretty much what looks like overnight doubling in size until you have full fledged mushrooms as shown below. Your first pins appear within four to seven days of the kit being exposed to the right conditions. High temperatures and low humidity may prolong or prevent any pinning at all.


zimbabwe oyster mushroom yield

Harvest time can follow within 5 days of the pins appearing. What I noticed was that nothing goes to waste as the mushroom stems are also suitable, very much so, for consumption. This also marked the epitome of my fulfillment in this whole project.

Road to market/Commercialization…

I take cognisance of the fact that the reader may be interested in going further than just this home experiment and actually commercialise oyster mushroom growing as a business. Since I have not gone this far yet, what follows are my opinions based on research and hands on experience relating to production processes as already explained.

First of all I think, commercialisation is possible and that’s why you find locally produced oyster mushroom in most supermarkets. So there is a clear opportunity there. However, I do think growing oyster mushroom as a business is a different ball game calling for key considerations.

Number one is your scale-ability because you will need to scale up production to be cost effective and make commercial sense and this applies to the entire production process and stages beginning with substrate sourcing, pasteurisation, and incubation. This actually calls for building of certain infrastructure for this purpose. This need not be expensive and it is actually not expensive.

You will also need to use substrate that increases your yield so you produce more with less. I personally don’t think peanut shells on their own are best for commercial production because of generally low yields. I have seen other farmers creating hybrid substrate for maximum yield. This hybrid yield will also produce a robust and attractive crop which is good for market.

mushroom for sale

Third, aim to knock price further down from the current average of US$1.00 per 200 g as obtains in supermarkets (as shown above). This does not push the necessary volume in my view. The whole industry needs millions of people to consume oyster mushrooms daily.

This can be only achieved by knocking down prices further even to under 50 cents per 200g at least in te current economic environment. It would appear, from my research, many farmers are not willing to do this due to the reduced margins in view of an already high cost of production.

I think the real winner is going to be the farmer(s) who can significantly reduce cost of production (this can be done) so as to make oyster mushroom a mass product. Countries such as South Korea have amazing mass production lines of mushroom in bottles and so on and I think this is what is needed. Mushroom in India is extremely inexpensive and accessible villagers consider it a staple.

What do you think? Got any questions please leave comment below.