The Sainsbury’s King Oyster Mushroom Clone Project
So, in the UK we have a supermarket called Sainsbury’s. They’re one of the few supermarkets in the UK that regularly stock ‘exotic’ mushrooms. To the UK consumer anything beyond a white mushroom is considered exotic so I think they’re pushing that terminology a bit there. They also happen to be in pretty poor condition having been crammed into the packaging, bruised and bent around each other, it gives a really bad first impression to people who want to try new mushrooms.

I’d just set my lab up in my shed and needed to test run my new-ish HEPA filter and all my kit, I’d knocked up some agar from Malt Extract and Agar Powder and shot down to Sainsbury’s.

Now, I didn’t take any photos of the inoculation because it was my first time cloning mushrooms, so I was concentrating, however out of the 5 petri dishes I inoculated only 2 became contaminated.

The other 3 survived but one was sacrificed when I dropped it on the floor so… The floor gods got their tribute I suppose. However, the other 2 were divided between 3 bags of Hardwood Fuel Logs, Wheat Bran and Gypsum in a ratio of 10% WB and 5% Gypsum.

I’ve not actually got any logic to my ratios, just a few glances on the internet said that is about right, upon further research that is the recommended dose. Although the gypsum isn’t necessary, I felt it would be worth trailing because it is so cheap and could contribute towards a greater yield… You never know.

The bags were sterilised in my ‘Bubba Barrel’ you can checkout my video by clicking Here or on my YouTube channel that discusses the design behind that. I have done a full write-up on how to build one, but I didn’t take pictures, so I need to build another one and take photos.


I then transferred the agar to my bags in front of my HEPA and heat sealed 2 and cable-tie sealed the third. I did this because I’m not having much luck with my heat sealer right now, the heat seems to be unevenly distributed along the entire length, meaning it ‘cuts’ half the bag and seals the other half which is irritating. I was using this opportunity as an experiment in putting Agar straight into the substrate rather than grains first.

I made a few rookie mistakes as I’ve never transferred agar, I double dipped my scalpel in one dish and my have ‘hung’ my arm over the lid too long. I also used my alcohol lamp but it wasn’t hot enough, so I BLEW IT OUT! WHAT AN IDIOT. I did, however, catch myself as I was doing it and re-sanitised the area. So, the biggest numbnut award today goes to me! Given that this was a ‘Straight Agar’ experiment i’m unsure of the outcome I should expect! But, that’s why we experiment isn’t it!
Thanks for reading! Please consider following my YouTube channel and Instagram for more updates! Bye-bye!
Hi Archer! So what was the outcome??
Hi Moose!
Success as far as I can remember! It’s a cheap way of getting some high quality genetics! I’d suggest giving it a go!
All the best!
Gareth