Hydrated Lime (Calcium Hydroxide) for Mushroom Cultivation

Hydrated lime is a fast‑acting pH booster used to cold‑pasteurise straw, coco coir and other low‑nutrient substrates. By raising the soak water to a high pH, it knocks back moulds and bacteria while adding calcium that supports firm, healthy mushroom fruit bodies.

Why Add Lime?

• Raises pH to 11‑12 in minutes, creating an inhospitable environment for contaminants.
• Allows cold‑water pasteurisation—no need for hot water or pressure cookers.
• Supplies readily available calcium, improving cell‑wall strength and shelf life.
• Cheap, effective and fully compatible with straw, coco, sugar‑cane bagasse and similar substrates.

Recommended Rates

• Cold‑Water Pasteurisation : 1 % w/v (10 g lime per litre of water). Soak straw or coco for 12‑18 hours, drain, then inoculate.
• pH Buff­ering in Bulk Mixes : 0.2‑0.5 % of dry substrate weight (2‑5 g per kilogram). Blend thoroughly before hydration.

Pack Size

500g resealable pouch of food‑grade hydrated lime (Ca(OH)₂). Store sealed in a cool, dry place.

Basic Use

1. Weigh the required lime.
2. Dissolve in clean water, stirring until fully suspended.
3. Add substrate, submerge completely and hold under the solution.
4. After the soak period, drain well, allow to cool if needed and inoculate.

Tips

• Wear gloves and eye protection—hydrated lime is caustic.
• Use a pH strip or meter to confirm the solution stays above pH 11.
• Do not mix lime with gypsum in the same soak; add gypsum after draining if needed.

Safety

Caustic substance—keep out of reach of children and pets, avoid breathing dust and rinse skin immediately if contact occurs.