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XL Rye Grain MykoBox Grow Kit
XL Rye Grain MykoBox Grow Kit - Image 2
spawnbox filled with grain

XL Rye Grain MykoBox Grow Kit

£35.00

Sterilised at 15 PSI in an electric autoclave, then processed and bagged under clean ISO4 filtered air-flow - before being heat-sealed shut.

Coffee-enhanced and ready to rock and roll.

Your favourite mushrooms will deliver 3+ harvests until the substrate is completely spent of nutrients.

This old classic makes a surprise return in 2026. Also, we're giving away 200g of dry coco coir substrate with this kit in case you want to go crazy and try a 33% monotub style grow. Otherwise put it in a drawer for your next grow (you don't need it).

  • 0-3 working day dispatch. Order and pay before 1pm Monday to Thursday.
  • Sterile gloves included. Tell us your glove size at checkout.

Rye Grain MykoBox with 1 injection

Inoculation

  1. Remove the MykoBox from its bag - it's already clean enough to inject but if you want, wipe the grey rubber port with the 70% IPA / 2% Chlorhexidine wipe
  2. Wait a few seconds for it to dry, then inject 2-3ml of gourmet syringe solution
  3. Place the MykoBox somewhere warm to fully colonise (23C is common for many species, give or take a couple of degrees)
  4. Follow the rest of the guide until harvest

The white HEPA filters on the lids will filter dust and mould spores and allow clean air exchange. Don't try to remove these!
NEVER open the MykoBox before full colonisation of mycelium or the kit will be ruined with contamination.

Read our detailed guide in the Grow guide section on this page

What's Included

  • 1200ml MykoBox of Coffee-enhanced Organic Rye Grain Substrate and Gypsum (18x12x7cm)
  • HEPA-Filtered and Inject-Thru™ lid system for ultimate contamination resistance
  • XXL Grow Tent to fruit your mushrooms inside, with filter material for its top-FAE gap
  • Hygiene Kit: face mask, 2 x hand wipes, 1 x 70% IPA / 2% Chlorhexidine wipe and 1 x spare sterile needle, plus sterile gloves (tell us your size at checkout)
  • 2L Perlite to maintain the perfect humidity level throughout the mushroom fruiting process
  • Bonus: Includes a bag of coir so you can optionally try MonoTub-style grows (you just add water and microwave)

The container

ContainerSAC O2 Microbox TP1200, from Belgium
Size1200 ml. Lid 180 x 120 mm, base 172 x 110 mm, 70 mm tall.
MaterialClear, tough polypropylene, so you can watch the mycelium grow. The lid seals airtight.
FilterWhite #30 filter in the lid: SAC O2's middle air-exchange grade, white rather than red so the colour is never confused with contamination.
How the filter worksRandomly arranged fibres, working on the HEPA principle, trap mould spores, mites and thrips while air passes through.
HeatCan be autoclaved at up to 123 °C.
AfterwardsBox and lid are 100% recyclable.

Not included

  • Gourmet Spore or Culture Syringe

Storage

If you cannot use your grow kit right away, we would advise that you store it in a (clean) fridge for a maximum of 2 weeks inside its clean bag.
If you can't store it in a fridge, don't leave it for any longer than 1 week.
The longer you leave it, the more moisture will be lost from the substrate and if too much moisture is lost, colonisation will just not happen.

Always inoculate your grow kits as soon as you possibly can!

Advice

  • This grow kit is tailored for all experience levels
  • Can be fully colonised in 10-14 days with a culture syringe, or a few weeks with gourmet spores, give or take, at optimum temperatures
  • Does not come supplied with a gourmet spore or culture syringe.
  • Some wood-loving species like Lion's Mane and Oyster will fruit on this substrate.

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