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Black Pearl King Oyster Mushroom Fruiting Block Kit

Black Pearl King Oyster Mushroom Fruiting Block Kit

Made fresh to order. To guarantee peak quality, your item will be dispatched within 30 Days.
Made fresh to order. To guarantee peak quality, your item will be dispatched within 30 Days.
Made fresh to order. To guarantee peak quality, your item will be dispatched within 30 Days.
£24.95 GBP
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Our Black Pearl King Oyster (Pleurotus ostreatus x eryngii) Mushroom Fruiting Block Kit is specially designed to yield thick, dense and delicious mushrooms with ease. These kits come ready to fruit and harvest, meaning there’s no need to faff around inoculating and colonising your own substrate; you can get straight to the fun part.  

Their large 3kg size and nutrient rich substrate make these some of the highest yielding grow kits on the market, capable of producing over 1kg of fresh mushrooms over several flushes!

🍄 3kg pre-colonised fruiting block that is ready to fruit   

⚖️ Grow large yields of up to 1kg+ of fresh Black Pearl King Oyster  

✨ Minimal space required to grow & requires little effort  

🗓️ Harvest mushrooms quickly within 2 weeks 

🛡️ Guaranteed to produce mushrooms or we’ll replace your kit free of charge  

Want to learn how to grow mushrooms with this kit? See our online guide here.  

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Description

THE HASSLE FREE, READY TO FRUIT SOLUTION TO GROWING BLACK PEARL KING OYSTER MUSHROOMS AT HOME 

Black Pearl King Oyster mushrooms has roots in East Asian cultivation, where Oyster and King Oyster varieties have been grown and cooked for generations. It is a relatively modern cross, but it carries the same practical appeal that made its parent varieties staples in home kitchens. 

Nutritionally, it offers the same general profile associated with Oyster and King Oyster mushrooms. It provides fibre and beta glucans (1), which some research suggests may support normal immune function as part of a balanced diet. It also contains B vitamins and minerals that contribute to everyday nutritional needs (2). 

Unlike thinner oyster types, Black Pearl King Oyster mushrooms develop a dense stem and broad cap with a firm bite. When you slice it thick and cook it slowly, the texture becomes layered and almost scallop like. If you score the stem and sear it in a hot pan with a little oil, it browns deeply and keeps its structure. It does not collapse into softness unless you overcook it.

Growing your own Black Pearl King Oyster mushroom at home has never been easier with our Black Pearl King Oyster Mushroom Fruiting Block Kit. Whether you’re a seasoned grower or a complete beginner, our kit takes the guesswork out of mushroom cultivation and turns it into a fun, straightforward process. Say goodbye to complex setups and hello to thick, dense, and luscious clusters of mushrooms, ready to be cooked, extracted or dried.   

Our kit comes with everything you need in one convenient package: a pre-colonised fruiting block that is ready to go right out of the box - no need for messy inoculations or waiting periods.   

Simply follow our easy step-by-step guide, and watch your mushrooms grow! With minimal effort and space required, you’ll be harvesting beautiful, delicious Black Pearl King Oyster mushrooms in as little as two weeks.  

THE BENEFITS   

  • Beginner-friendly; no prior experience or knowledge required 
  • Harvest up to 1kg of fresh Black Pearl King Oyster from a single block 
  • Ready-to-fruit block makes the process quick and easy  
  • Guaranteed to produce mushrooms or we’ll replace your kit free of charge  
  • Save money by growing your own mushrooms at home 
  • Little space required to grow & is discreet with no smells 
  • Black Pearl King Oyster mushrooms are packed with bioactive compounds like beta-glucan   

HOW TO USE  

The process is simple:  

Prepare the Block: Cut a small “X” or slit in the side of the block. 

Maintain Humidity: Maintain a humid environment by misting the block two or three times daily or using a humidity tent.  

Humidity-Controlled Chamber: Alternatively, you can place the fruiting block in a chamber such as a MonoTub or Martha tent for optimal growth, as this will help maintain ideal fruiting conditions. 

Harvest: After around 14 days, the mushrooms should reach full size. Gently twist at the base to harvest. 

Gone are the days of having to trawl through decade-old forum posts to figure out the fascinating but often confusing science that is growing mushrooms. Our step-by-step, easy-to-follow guide ensures a successful harvest, eliminating guesswork and making the whole process a breeze.  

GROWING CONDITIONS  

Temperature:   

  • Colonisation: Around 25°C (77°F) for optimal mycelium growth.     

  • Fruiting: 13–17°C (55-63°F) to encourage primordia formation.  

Humidity: High humidity (over 80%) is essential for healthy, large fruits. Use misting, humidifiers, or a fruiting chamber to maintain humidity.     

Light:   

  • Colonisation: Complete darkness is preferred for rapid colonisation.     

  • Fruiting: Indirect sunlight or ambient light is sufficient.  

Fresh Air Exchange (FAE): Proper ventilation is necessary to provide the growing mushrooms with fresh air and prevent the buildup of carbon dioxide, which can inhibit growth.     

Sterility: Maintaining a clean and sterile environment is paramount to prevent contamination from other fungi or bacteria, which can compete with the mycelium and hinder its growth.  

INGREDIENTS   

Good ingredients make for excellent grow kits. That is why we only use 100% natural and organic grain and masters mix substrate in our kits. We only use high-quality, natural ingredients for our products, specifically selected to support the optimal growth of Black Pearl King Oyster mushrooms.  

Our proprietary substrate blend is a mix of optimally hydrated millet grains, milo grains, hardwood pellets, soy hulls and gypsum. This mixture is carefully hydrated to field capacity and sterilised in a computer-controlled steam autoclave for 2 hours at 121°C.   

The result is an optimal 6:1 substrate to spawn ratio. This is then inoculated with our own Black Pearl King Oyster liquid culture, the substrate providing the perfect nutrient rich environment for mycelium, promoting rapid colonisation, large yields and minimal risk of contamination.   

WHAT’S INCLUDED  

  • 3kg Black Pearl King Oyster Fruiting Block

  • Ultra Fine Mister (Optional)  

  • Humidity Tent (Optional)  

WE DO NOT INCLUDE   

Physical copy of the growing guide: You can find our online step-by-step mushroom growing guide here, as well as some of our own tips and tricks for optimising your grow. We highly recommend reading it before purchasing!  

STORAGE  

Please aim to use your Black Pearl King Oyster Mushroom Fruiting Block Kit soon after receiving it. If you are not using right away, store the bag in the fridge. Stored this way, your kit should last at least 3 months.  

  • EASY TO USE

  • MASSIVE YIELDS

  • SET & FORGET

  • SAVE MONEY

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What people are saying

MUSHROOM GROWING MADE EASY

  • INJECT BAG

  • WAIT 4-6 WEEKS

  • HARVEST MUSHROOMS

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MARTIAN MUSHROOMS

  • Can grow multiple mushrooms
  • QC lab tested for contaminants
  • Easy to use with help from our mycologists
  • Lifetime guarantee protected
  • High yielding masters mix substrate blend
  • Rapid colonisation times
  • Simple set & forget growing
  • Fun step by step guided process

GENERIC GROW KITS

  • Only grows a few species
  • Untested for contamination
  • Difficult to use without any on hand help
  • Not protected if something goes wrong
  • Lower yielding substrate
  • Slow colonising weak genetics
  • Lots of steps to get mushrooms
  • Frustrating to use with long process

FAQ

DOES THIS COME WITH SPORES OR CULTURE SYRINGE?

There is NO spore or culture syringe included with the Blank Grain Spawn Bag. It is non-inoculated to allow you to inject the species of your choice. Liquid cultures for gourmet varieties are available here.

HOW MANY SYRINGES DO I NEED?

You only need 5ml of spore or liquid culture solution per bag, so one syringe can inoculate 2 bags. We don’t recommend using more than 5ml per bag, because too much liquid can throw off the moisture content within the bag. 

You can store any unused solution in the fridge for future use. Stored that way, they’ll keep for many months. 

HOW IS THIS GRAIN BAG USED?

Fortunately, it’s really easy to use, you just need to follow our guides by clicking here.

HOW DO I STORE THIS GROW KIT?

Ideally do not store your grow kit and inoculate right away, if you are not using right away keep your kit in the fridge.

WHAT MUSHROOMS CAN BE GROWN WITH THIS KIT?

Our Martian Mushrooms kits are designed with versatility in mind and can support the growth of various edible and ornamental mushroom species. Some popular types of mushrooms that can be grown with our kits include Oyster mushrooms, Shiitake mushrooms, Lion’s Mane, Reishi, Chaga, Turkey Tail and many others that are legal and safe for cultivation at home.

It’s important to note that while our kits can technically support the growth of various types of mushrooms, we strongly advise against and do not condone the use of our kits for the cultivation of mushrooms that are illegal to grow in your country. This is due to the legal restrictions in many regions, including the UK where we are based, it is illegal to cultivate certain species of mushrooms.

At Martian Mushrooms, we are committed to promoting responsible and legal use of our products. We reserve the right to refuse service to anyone suspected of intending to use our products for illegal purposes. Always check and comply with your local laws and regulations regarding the cultivation and possession of mushrooms. Any customer service requests regarding the cultivation of illegal species will be ignored. 

CAN I GROW MULTIPLE TYPES OF MUSHROOMS WITH THE SAME KIT?

We dont recommend growing more than one type of mushroom per kit. Growing multiple types of mushrooms may result in poor flushes.

WHERE DOES THIS PRODUCT SHIP TO?

Please refer to our delivery details 

HOW LONG DOES IT TAKE TO GROW?

It will depend on a few different factors, mainly temperature. But it will range from about 4-8 weeks. 

FAQ

Our pre-colonised Black Pearl King Oyster Mushroom Fruiting Block Kit doesn't include spores or liquid culture, as it is already pre-colonised with Black Pearl King Oyster mycelium and ready to fruit.  

Fortunately, it’s really easy to use; you just need to follow our guides by clicking here.

  • 3kg Black Pearl King Oyster Fruiting Block  
  • Ultra Fine Mister (Optional)  
  • Humidity Tent (Optional)  
  • Our Lifetime Guarantee  

WE DO NOT INCLUDE   

Physical copy of the growing guide: You can find our online step-by-step mushroom growing guide here, as well as some of our own tips and tricks for optimising your grow. We highly recommend reading it before purchasing! 

Please aim to use your Black Pearl King Oyster Mushroom Fruiting Block Kit soon after receiving it. If you are not using it right away, store the bag in the fridge. Stored this way, your kit should last at least 3 months. 

Please refer to delivery details. 

Black Pearl King Oyster mushrooms typically take about 1 to 2 weeks to start fruiting from a fully colonised block, provided the conditions are optimal. This timeframe depends on maintaining the right environment, including high humidity (85-90%), temperatures around 13-18°C, and proper air exchange. Once pins appear, they usually take 7 to 10 days to develop into full-sized fruiting bodies, with the thick, marbled stems and dark, pearl-like caps becoming more robust and defined as they mature. This hybrid variety grows more slowly than standard Oyster mushrooms, but the result is a significantly meatier texture that is highly prized for culinary use.

Biological products, by their very nature, can be unpredictable and sometimes things don’t go as planned. Growing mushrooms is always a battle against contamination, and sometimes it wins.   

When things go wrong, don’t worry. We offer replacements for contaminated kits or substrates as our guarantee.   

Ensure the humidity is high by misting two or three times daily or using a humidity chamber. Make sure there's enough airflow by providing proper ventilation. Keep the temperature between 15-20°C (59-68°F) and place the kit in indirect light. If the substrate looks dry, mist more often or soak it briefly and let it drain. Sometimes, it just takes more time, so be patient. Check for any contamination, like mold. If you still need help, contact our support team!

Black Pearl King Oyster mushrooms are particularly sensitive to high CO2​ levels during their pinning and growth phases. If there isn’t enough Fresh Air Exchange (FAE), they may develop excessively thick, elongated stems with very small, stunted caps, or in some cases, fail to fruit altogether.

Ensure your setup maintains high humidity through regular misting while providing enough airflow to prevent CO2​ buildup. Finding the right balance between humidity and ventilation is the key to encouraging the development of those signature large, dark, pearl-like caps.

Yields can vary substantially based on the genetics of the mushrooms you’re growing, environmental conditions and size of the kit you purchased. Typically, you can expect to grow 1kg+ fresh mushrooms over several flushes from our 3kg fruiting blocks. 

If we did not answer any of your questions above, then contact us here. We are always happy to help and look forward to hearing from you.