• 250g bag of fine grade gypsum for mushroom spawn supplementation
  • Fine Grade Gypsum (Calcium Sulphate) For Grain Spawn Supplementation
  • 500g bag of fine grade gypsum for mushroom spawn supplementation
  • 1KG resealable bag of fine grade gypsum for mushroom spawn supplementation
  • 2KG resealable bag of fine grade gypsum for mushroom spawn supplementation
1 5

Gypsum Fine Grade | Grain Spawn Substrate Supplementation

Gypsum Fine Grade | Grain Spawn Substrate Supplementation

$8.00 AUD
$8.00 AUD
Sale Sold out

Low stock: 10 left

Fine grade calcium sulphate (gypsum), a trusted mineral additive used by mushroom growers to improve grain spawn quality and promote robust mycelial health.

Our gypsum is ultra-fine and food-safe, perfect for evenly mixing through hydrated grain prior to sterilisation. It helps prevent clumping, balances pH, and provides essential calcium and sulphur—key nutrients for vigorous mycelium growth.

Benefits

- Improves grain texture and flow
- Helps reduce grain sticking/clumping
- Enhances calcium and sulphur availability for mushroom
pH stabilising properties
- Suitable for sterilisation or pasteurisation

How do I use it?

Add 1–2% by dry weight to hydrated grains before sterilisation. Mix thoroughly for best results. Commonly paired with millet, wheat, rye, or sorghum grain for gourmet mushroom spawn.

Available Sizes

250g – Great for hobbyists & small batches
500g – Ideal for regular growers
1KG – Cost-effective for ongoing projects
2KG – Best value for larger or frequent grows

Delivery Information

  • We ship from Tamborine Mountain, QLD using either AusPost or Aramex
  • Fast dispatch within 1 business day (excluding Fridays) with express post options available
View full details
Customers rate us 4.8/5 based on 31 reviews.