The B+ XL Magic Mushroom Grow Bag contains a fully colonized substrate with Psilocybe cubensis B+ mycelium. This well-known variety is valued for its robust growth character, recognizable golden-brown caps, and classic cubensis shape. Because the substrate is already fully colonized, several preparatory steps of the cultivation process have already been completed.
B+ is one of the better-known varieties within the Psilocybe cubensis family. The species is known within the cultivation world as relatively accessible and forgiving. As a result, B+ is often chosen by novice growers, but the variety also remains interesting for experienced enthusiasts.
The fruiting bodies typically develop sturdy, light stems with golden-brown to caramel-colored caps. Under suitable conditions, B+ can form relatively large fruiting bodies, giving the species a recognizable appearance.
The B+ XL Magic Mushroom Grow Bag contains 2,200 ml fully colonized substrate. This means you don’t have to inoculate with spores yourself or sterilize and prepare the substrate. The grow bag can be prepared for the fruiting phase according to the included instructions.
Under suitable conditions, the total yield according to product specifications can reach approximately 700 g of fresh mushrooms. The actual yield varies per grow and is influenced by factors such as temperature, hygiene, air exchange, and general care.
B+ has a relatively robust growth character. Nevertheless, it remains important to keep conditions stable during the fruiting phase and to give the mycelium enough time to develop.
B+ belongs to the psilocybin-containing Psilocybe cubensis varieties. The psilocybin experience can vary greatly per person and is influenced by the amount used, individual sensitivity, mindset, and environment.
The amount of active compounds in natural mushrooms can vary per harvest and even per individual fruiting body. Therefore, a specific strength or experience cannot be guaranteed.
B+ is an established variety of Psilocybe cubensis that has been present within the mycological cultivation world for a long time. Various stories exist about the exact origin of B+, meaning the full genetic history has not been established with certainty.
The variety distinguishes itself mainly by its classic appearance and relatively robust development. The caps are typically golden-brown to caramel-colored and become wider and often somewhat lighter in color during development.
Compared to more demanding varieties such as Penis Envy, B+ generally has a more accessible growth pattern. This makes the species interesting for growers working with a fully colonized Psilocybe cubensis grow bag for the first time.
Make sure your work area is clean to prevent other microorganisms from contaminating your grow kit. Working hygienically is important throughout the entire cultivation process.
Always use clean tap water or mineral water when required by the instructions. Do not use distilled or demineralized water.
Download the PDF instructions here: MysticFungi Instructions
Carefully check the grow bag before you start cultivation.
Is the grow bag contaminated or damaged?
If so, contact customer service before starting the grow.
A clean working method helps limit the risk of contamination during the cultivation process.
Important: only open the grow bag when the first mushroom pins (pins) are visible.
Leave the grow bag alone as much as possible during this phase. The moment the first pins appear can vary per grow.
Once the first pins are visible:
A small slit may be visible under the air filter of the grow bag. This opening was made by the manufacturer to release excess CO₂ and built-up pressure when the grow bag bulges. This is normal and not a defect. The opening does not need to be taped shut.
For the best results, start the cultivation as soon as possible after receipt. Postponing the grow can affect the condition and ultimate performance of the mycelium.
If you cannot start immediately, the grow kit can be stored for a maximum of about two weeks in the refrigerator at 2°C to 8°C. Leave the grow bag with mycelium in its original packaging and place it in a clean refrigerator without visible mold.
For extra protection, the packaging can be placed in a clean plastic bag or an additional grow bag. Do not leave the kit outside the recommended storage conditions for unnecessarily long periods.
Valid from September 21 to 30, 2026
Use the code below at checkout to receive 15% off your entire order.