How to store growkit?

How to store a growkit properly?

Growkits can seem mysterious at first glance—not only because of their association with psychedelic research, but also because many people are not familiar with the biological nature of the mycelium inside. To make the topic clearer, we have prepared a detailed explanation of what a growkit is, how its substrate behaves, and how to store it correctly so that it maintains its freshness and research quality for as long as possible.

What is a psilocybin mushroom growkit?

A growkit (also referred to as a grow box, cake or grow kit) is a sterile block of colonised substrate formed into a compact cube and placed in a sealed plastic container. When properly hydrated and kept under the right laboratory conditions, this substrate is capable of producing fruiting bodies. The idea behind a growkit is simple: the manufacturer inoculates a nutrient-rich substrate with fungal spores under sterile conditions. Each variety of mushroom corresponds to a different type of growkit, and you can check available strains here: https://www.psychodelicroom.pl/en/growkit.

The growkit is a biological product and therefore sensitive to temperature, contamination and time. Although the concept may seem unusual for beginners, proper storage is surprisingly straightforward once you understand its needs.

Growkit storage — how long is it fresh?

According to the manufacturer, a growkit can remain fresh for up to six months from the moment of purchase—*but only if stored correctly*. In our shop, psychodelicroom.pl, every delivery is placed immediately into dedicated cold rooms maintained at a constant 2–4°C. Thanks to this, growkits remain in ideal laboratory storage conditions until they are shipped to you. Our rotation is monthly, which means that customers always receive products that are very fresh and of high research quality.

How to store a growkit at home?

When your package arrives, place the growkit in the refrigerator as soon as possible. Keep it separated from raw foods or open containers to minimise contamination risk. The growkit should stay refrigerated until you are ready to begin observation or laboratory examination.

How long can a growkit stay outside the refrigerator?

The answer depends mostly on ambient temperature. During the summer months, transport time should be kept as short as possible. We strongly recommend choosing courier delivery instead of parcel locker collection, as lockers may reach high temperatures. If a parcel machine is used, pick it up immediately after receiving the notification.

Even though a growkit can theoretically survive several days in transit, heat may cause it to become “tired”—the substrate may begin to prepare for fruiting, changing appearance (yellowish or cream areas). Higher temperatures accelerate the end of its hibernation cycle. The manufacturer once indicated that a growkit may tolerate up to roughly 10 days outside refrigeration, but its long-term freshness will be significantly reduced.

Can a growkit tolerate freezing temperatures?

Growkits do not respond well to temperatures below zero. When the temperature outside drops a few degrees below freezing, it is safest to postpone delivery or wait for a short thaw period. During winter, we additionally use insulated packaging. Courier services are again the recommended option, because shipments do not sit outside for long hours.

Interestingly, some users have reported that accidentally frozen growkits still performed well in laboratory examination. However, this is the exception, not the rule, and freezing is strongly discouraged as it can damage the structure of the mycelium.

Is a growkit legal?

In Poland, possession of a growkit is legal. What is illegal is allowing it to produce fruiting bodies. Psilocybin mushrooms are prohibited in Poland and many other countries, therefore products available in our shop are intended exclusively for research, laboratory analysis and collection purposes. Allowing the mycelium to fruit may put you in conflict with the law. More information can be found on our blog.

Summary

To store a growkit correctly: keep it refrigerated, avoid heat exposure during transport, and minimise the time from shipment to cooling. Remember that mycelium is living organic material—sensitive, dynamic and sometimes unpredictable. Even if the growkit spent several days at +30°C or briefly encountered frost, it may still be suitable for research. Each case is unique, so don’t give up too quickly. Patience and proper handling can make a significant difference.

The content on the psychodelicroom.pl website is educational, research-based, and expresses many opinions that should be treated with caution. We advise against using any substances that affect consciousness, as all of these substances can both heal and be very harmful. In particular, we advise against cultivating mushrooms from growkits in countries where it is illegal – including Poland – because it involves criminal liability. We recommend that you dispose of the growkits purchased from us within 72 hours of receiving them.