Organic Blue Oyster Mushroom Grow Kit Fruiting Block
|Grow speed||1 to 2 weeks|
|Shelf life||6 months (refrigerated)|
|Kit dimensions||6in H x 9in W x 6in D|
|Kit weight||5 lbs|
Our blue oyster (Pleurotus ostreatus) fruiting block features a strain that produces beautiful clusters of mushrooms with bluish-gray to brownish-gray caps, depending on lighting conditions. They have a rich umami flavor and a soft meaty texture that lends itself to most recipes.
Blue oyster mushrooms are great for beginners as they are reliable producers and tend to grow large flushes. They are also one of the easiest blocks to get subsequent fruitings and, if kept in the right conditions, should reliably produce a second flush or more!
Upon receiving your kit:
Remove kit from the shipping box as soon as possible. Then, unfold the top of the bag, making room for air space. It's also important to check and confirm that the filter patch is not obstructed. This will help the organism breathe and continue to thrive until you are ready to grow your fruiting block!
Scroll down for guides on growing, storage, cooking, and more.
For the majority of mushroom species, all that is needed to initiate fruiting (or begin the growth cycle) is a change in environmental conditions -- specifically humidity, light, temperature, and changes to oxygen and CO2 levels.
For best results:
We recommend growing your blue oyster block in a fruiting chamber (like a monotub or martha tent) as a controlled environment will decrease the risk of contamination and increase the chances of success.
Creating optimal conditions:
The environmental parameters for blue oyster mushrooms can be found on this page under "Temp, Humidity & CO2 guide" and on page 3 of our fruiting block instruction booklet.
Preparing your block:
Tightly fold excess plastic back and place the block face up.
How to initiate fruiting:
- Slice bag with a single diagonal line or with an X.
- Blue oyster mushrooms can be top or side fruited.
- Blue oyster mushrooms are prone to forming long stems and small caps when CO2 levels are too high.
- Cooler temperatures and more light will produce a more pigmented cap.
Harvesting your mushrooms:
Harvest young, when edges of caps are still slightly turned under. (When harvested younger, less spores will be produced and shelf life will be extended.) Remove entire cluster with care to minimize breaking.
Growing different blocks together:
With some compromise, many different species of mushrooms can be grown together in a fruiting chamber. First, consider the temperature range of the mushrooms you desire to grow, and second, the CO2 sensitivity. Humidity ranges overlap for the majority of species. We encourage you to experiment with many different groupings!
Having issues with unusual growth, stunted growth, or no growth at all? Refer to pages 16-18 in our fruiting block instruction booklet.
Temperature 55-75°F | 13-24°C Humidity (Phase 1: Primordia) 95-100% Humidity (Phase 2: Fruitbody) 85-95% CO2 Sensitivity (Phase 1: Primordia) <1,000 ppm CO2 Sensitivity (Phase 2: Fruitbody) <1,000 ppm
- Primordia - The earliest recognizable stage of fruitbody development. Also known as “baby mushrooms” or “mushroom pins.”
- Fruitbody - A fully grown mushroom, the reproductive structure of the organism in which the spores are produced.
- CO2 sensitivity - When CO2 levels are too high, yields will decrease, stems will become long and stringy, caps will be small, and/or growth will halt.
If you don't plan to use immediately, you can refrigerate your block for up to 6 months.
The classic North Spore recipe is to slice up oyster mushrooms and sauté them in a heavy pan on medium heat with butter, garlic, and loads of fresh thyme and rosemary (or whatever other herbs you happen to have on hand!). Cook until the mushrooms have released their liquid, then continue cooking until that liquid has cooked off and the mushrooms begin to brown. Deglaze your pan with a splash of white wine, reduce once more, and finish with a touch of heavy cream. Season generously with salt.
Like all Oyster mushrooms, they retain water and may develop a viscous texture when under-cooked. If you prefer a firm or dryer texture, continue to cook Oysters until their liquid has reduced and cooked off and they begin to brown.
If you’re going to consume home-grown mushrooms, make sure to cook your fresh mushrooms thoroughly with heat. If it is your first time eating this species, it is best to start with a small amount to check for allergies, even if cooked.
Mushrooms grow spores as they develop. This is a natural means of reproduction. This is when people with allergies or compromised immune systems may want to consider putting fruiting mushroom kits outdoors or in a well-ventilated area. Spores in mushrooms sometimes cause respiratory irritation. In rare cases, spores may also cause irritation for some non-allergic or non-immunocompromised mushroom growers. If you are one of them, it is recommended to reduce the overall spore load by harvesting mushrooms while they are still in their younger growth stages.
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very easy and consistent to fruit them, getting almost exactly 1 lb of mushrooms on our first flush
Your grow looks amazing, Michael! We’re so glad everything is working out for you.
Quick primordia / pins
I let the block colonize for two weeks after I received it. Introduced O2 and light this week primordia And pins in 5 days. Going nicely and very healthy.
We haven't used it yet.
I like your company
Thanks, Paul! The team is here to help if you ever need anything.
Block arrived very quickly and yield was great!
Fun and easy
Pins formed about a week ago maybe? Tonight I’ll be harvesting massive blue oysters for pasta dinner! This makes mushroom growing within ANYONE’S reach. Great teaching tool and great for inspiring future gardeners and mycologists
Tasty and have gotten 3 flushes out of the block.
Fast and strong colonizer!
I inoculated a bucket filled with hydrated packing paper and aspen wood chips with this spawn back in late April. I did not do any pasteurization. I figured blue oyster mycelium is aggressive enough it shouldn't have an issue. The bucket colonized and produced its first fruiting in just a month! I had previously figured it would take a little longer and was pleasantly surprised when I noticed pins poking out thru the holes late last week!
Got three great flushes! Photo doesn’t do these mushrooms justice. Highly recommend!
Blue, Blue, Blue, Blue Moon!
Very productive! I've had up to three flushes from blocks, and three or more flushes from buckets and baskets of straw! Watch North Spores video in growing in buckets and get more BANG for your buck!
Within 6 days of slicing the bag, I harvested 1.6 pounds of delicious blue oyster mushrooms! Getting ready to go for a second flush, then into buckets of straw! I use equal amounts of very lean hamburger and oyster mushrooms to make the best meatloaf I've eaten in the past 70 years!