Jack Frost — Ready-to-Grow Bag XL — Cloud920®

Jack Frost is the most potent Psilocybe cubensis in our catalogue — a deliberate cross between True Albino Teacher and Albino Penis Envy, bred by Dave Wombat in 2018. Snow-white mushrooms, flat caps that curl upwards, and a psilocybin content of 10–12mg per gram: this strain is reserved for growers who are ready for it.

First pins typically appear between 3 and 5 weeks. This is by design. Adjust your dose accordingly.

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€52.50
Product Description
Details

Jack Frost is not for the impatient — and that's exactly why it has a cult following. This snow-white Psilocybe cubensis is the strongest cubensis in our catalogue, bred for extraordinary potency and a frosty appearance unlike anything else you have grown. It takes its time. It rewards patience. And once it fruits, it does not disappoint.

Part of the Cloud920® Genetic Series — Hybrid Fusion


Origin & Genetics

Jack Frost is a deliberate cross between two albino legends: True Albino Teacher (TAT) and Albino Penis Envy (APE). From TAT it inherits reliable yields, strong flush potential, and a forgiving temperament. From APE it inherits its concentrated potency and slow, methodical growth. The result is a strain that looks like both parents — fully white, frostbitten stems and caps that curl upwards like snowflakes — and hits harder than either of them alone.


Why Choose Jack Frost?

  • Strength: ★★★★★★ (6/6) — the strongest cubensis we carry. Even experienced users recommend starting low at 1–1.5g and working up from there.
  • Documented genetics — unlike most cubensis whose origins are folklore, Jack Frost has a traceable breeder and verified parentage. You know exactly what you are growing.
  • Multiple heavy flushes — expect 400–800g fresh across multiple flushes from one kit.
  • Built for the bag format — Jack Frost's slow colonisation style suits the sealed Cloud920 bag perfectly. Minimal intervention, maximum result.

⚠️ Jack Frost takes longer than most strains — and that's a feature, not a bug. First pins typically appear between 3 and 5 weeks after setup. This is not a sign of a failed kit. Jack Frost grows slowly because it puts its energy into density and potency rather than speed. Growers who stay patient are consistently rewarded with heavy, thick-stemmed flushes. If you're at week 3 with no pins yet: you're exactly on schedule.


What's in the Box

  • 1x Cloud920 Grow Bag — 2000cc pre-colonised substrate with active Jack Frost mycelium. Integrated micron filters provide passive air exchange and contamination protection.
  • 1x Large bag clip — to seal the bag securely between ventilation sessions.
  • 1x Rubber band — place around the substrate block to prevent unwanted side growth.


How the Cloud920 Grow Bag Works

  • Open once — fold the bag open in a clean space to allow fresh air in and trigger pinning.
  • Place and wait — put the bag in indirect light at 23°C. No soaking, no misting required in the first phase.
  • Air daily from week 2 — briefly open and refold the bag once a day to encourage pin development.
  • Harvest and repeat — twist and pull mushrooms at the base before caps open fully. Rehydrate and repeat for additional flushes.


Instructions

The Cloud920 Ready-to-Grow bag does not include printed instructions. Find the full step-by-step guide here: Cloud920 Grow Bag Instructions.

Additional Info
Additional Info
Productcode MCS.GKC920.JFRO-XL
Weight (KG) 1.4000
Mushroom Strain Jack Frost
Brand Cloud920® Grow Bag
Difficulty Very Easy
Size Extra Large
Species Psilocybe cubensis
Origin United States
Potency High
Optimum cultivation temperature 23ºC
Yield (from) 200 grams
Yield (to) 800 gram
Water Spray Needed Yes

Customer Reviews

Items 61 to 74 of 74 total

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Mixed results, but still satisfied! Review by S
Rating
I had 3 of these, first gave me in total around 400 grams fresh, with multiple 100+ grams shrooms!
The other 2 where less succesful, still a decent harvest but both got contaminated after the first flush, so had to throw them away.

Also, i think they do need some more fresh air , venting them seemed to improve grow speed and jield.

Potency is above average, compared to mckennaii I say around 1,5 times as potent. (Posted on 7/25/2024)
The best I've tried so far. Review by Krisdis
Rating
Hello, the whale came very quickly. And growing these mushrooms is very easy. You set up and wait. After a good three weeks, the first little mushrooms were visible. After a week, I picked up the first round. I got 300g of fried mushrooms. I put the whale back in place, and the next round begins. The next cycle starts very quickly, after two days already a new one. The effect of the mushrooms is very intense and they work very nicely, and they are really strong. Thank you for such a good product. I recommend it to all cosmonauts. ???? (Posted on 7/2/2024)
Great kit, very powerful mushrooms Review by M.
Rating
This is my first experience growing mushrooms.

At the beginning I had delayed growth issues after the first tiny mushrooms appeared. Frank from support was super helpful, and more importantly he was spot on with the diagnosis: too much CO2, and I just needed to ventilate the kit. Once I did, after a few days the mushrooms started to grow properly. But unfortunately the few little mushrooms that were there were already starting to rot.

Maybe due to the initial issues, the first flush was very uneven in terms of maturing, and I had to harvest mushrooms every day for more than a week (which I didn't mind at all - quite the opposite: I enjoyed the process a lot). Despite the issues, I collected 240g of fresh mushrooms from the first flush alone.

After that, I soaked the kit (because the cake had shrunk quite a bit and it was a lot drier), then after that I got another flush in less than 2 weeks. This time most mushrooms matured at the same time, and I collected 140g of fresh mushrooms, including some massive ones of 35g+.

Now I soaked it again and I'm waiting for the 3rd flush. I'm ventilating the kit daily at this point.

Be careful - these mushrooms seem really powerful! I haven't done a proper trip yet, just micro dosing using 0.1g of these rotten ones from before the first flush. That's a dose so low that you're not supposed to feel anything, yet I could definitely feel my heart racing and my head lighter. I had to lower the micro dose at 0.05g for no noticeable effects.
For my first trip, I'll definitely start slow and go low with the initial dosage, even if I'm looking for a very strong effect.

I'd definitely purchase this kit again! (Posted on 6/3/2024)
Efficiency Review by Predictor
Rating
Effortless growing. Everything went as written in the description. Mushrooms are huge and grow fast. I can feel the cake shrink and become lighter in just a few days. They are also potent. Try starting with half of what you usually need with Golden Teacher. Hard to eat plain raw but they go well raw with soy sauce. (Posted on 5/21/2024)
Just what you've been waiting for Review by Roman
Rating
Hello everyone. I have tried many different grow kits from this website, and have been very satisfied with the products, however, Jack Frost is my new favorite. The other growkits were pretty easy to grow - activate and then once the first pins occur, just open the bag twice per day, air out and mist some water in the bag. Jack Frost brings the simplicity to the whole new level: all you have to do is open the bag once you receive it and close back again - you don't have to do anything more - just wait for the mushrooms to grow and harvest them. Just like the instructions said, the bag had enough moisture inside for 2 yields, so you will be able to harvest a couple of hundred grams without having to do a single spray. Regarding the potency, Jack Frost is as potent as other cubensis strains. Therefore, Jack Frost requires by far the least amount of effort per unit of psilocybin produced, compared to anything else I have seen. To sum up, if you wanted to grow your own mushrooms, but was not sure if you can committ to airing them and watering twice per day (if you travel a lot etc.), Jack Frost is what you have been waiting for! I am glad that growing your own medicine is becoming more and more accessible to everyone. That's my take on Jack Frost - hope this review was useful. All the best and take care! (Posted on 5/19/2024)
Jack aus dem Beutel Review by L+
Rating
Ja was soll ich sagen... beeindruckend 1.Flush am Ende 30g trocken und der dickste Kollege wog frisch stattliche 84g.
Hab nach einer Woche Ruhe die ersten Pin's vom 2. Flush...
Hammergeil der Jack aus dem Beutel! (Posted on 5/14/2024)
Biggest Shrooms I ever harvested Review by Maximilian
Rating
These shroomies are defenitly worth trying. defenitely the biggest and most potent on the page. My first yield was just one shroom but it filled out the whole inside and weight 101g :D. A week later the rest came and were a bit smaller but still hudge. I tryed it a couple of times raw and had a good time. quite strong body high (a bit like on xtc) compared to the other cubensis strains. 2nd flush is already sprouting... Will buy again.
Cheers! (Posted on 5/13/2024)
Frozen ! Like Elsa Review by Mario
Rating
I had one piece raw and it was great! I had so much fun. Easy to grow and potent ! With a little more you get frozen like elsa (Posted on 5/9/2024)
Easy and good Review by RS
Rating
Very simple to use and great first flush. Recommend! (Posted on 5/9/2024)
Got no growth Review by Denis
Rating
I got nothing but the different mushroom kit I got was just fine (Posted on 4/29/2024)
Love those! Review by Flo
Rating
They are easy to set up, the yield on my first flush was nearly 300 wet, tryed some fresh and its enough to let me talk with god for a long time! (Posted on 4/27/2024)
Great value Review by M
Rating
The flushes are around 200 g (20 g dried) and it´s very easy growing. Much better than most other boxes. Only downside is the side pins, but they exist with other methods too, so not a big issue. Will try another method next time to see if it works better. Very happy with overall results (Posted on 4/25/2024)
Easiest kit ever! Review by KD
Rating
Since I need to travel more for work these days, I asked the fabulous customer support team if there was any kit that would still grow okay without daily attention. They recommended Jack Frost, which was even simpler than I expected – I did the usual careful sanitary set-up on the day it arrived, in a space in my flat where it would get the right kind of light, then – following the instructions – I didn't even touch the kit again until the first flush was ready to harvest 2-3 weeks later. Huge flush, very pleased ... just one note of concern – I probably harvested a day late, and some of the mushrooms were already starting to degrade a little bit. I'm wondering if the Jack Frost growing method might yield mushrooms that need to be harvested promptly when the caps open, no procrastinating... Perhaps there is a more humid environment in the bag, and thus a smaller window of time for harvesting the mushrooms than with other kits. I'm not sure, but this is a small matter – I will definitely be continuing to buy this great kit in the future. (Posted on 4/12/2024)
Very good experiance Review by Mantas
Rating
I was happy with grow box, grow very good and fast, easy growing ,
Mushrooms are big and full from inside , good quality. I recomend! (Posted on 4/12/2024)

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Important information about Jack Frost — Ready-to-Grow Bag XL — Cloud920®

  • The purchase of this product is restricted to individuals who are at least 18 years old.
  • By initiating a purchase, you confirm knowledge of and compliance with the legal terms regarding the product(s) in your country of residence, as well as your eligibility to acquire and hold them.
  • Shipping restrictions apply to this product. Refer to Additional Info to discover our non-delivery zones.
  • Engaging in the consumption of magic mushrooms is solely your responsibility, so be certain to thoroughly educate yourself about their usage and consequential effects.
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