Slaked Lime (Ca(OH)₂)

🧪 SLACKED LIME (CALCIUM HYDROXIDE): A valuable mineral additive for adjusting the pH of growing media, particularly for gourmet mushrooms such as oyster mushrooms.
⚖️ pH REGULATION: Raises and stabilizes the pH of the substrate, preventing the growth of unwanted microorganisms and promoting rapid mycelium colonization.
🌿 HYGIENIC PREPARATION OF THE SUBSTRATE: Ideal for cold water lime pasteurization, ensuring a healthy substrate without cooking.
🔧 EASY TO USE: Mixes easily with straw or other lignocellulosic materials, making substrate preparation quick and efficient.

€5.00

Packaging

500 g
5,000 g

- +

Categories:
Laboratory Culture Media

Slaked lime, also known as calcium hydroxide, is an additive commonly used in the preparation of substrates for growing certain mushrooms, particularly species that tolerate or require a substrate with a basic pH (such as certain Pleurotus or Stropharia species).

The Role of Slaked Lime in Mushroom Cultivation

1. Increase in the pH of the substrate

The primary function of slaked lime is to raise the pH of the substrate, often rapidly and significantly. This helps to:

Create an environment that is hostile to many contaminants (bacteria, mold).
Choose mushrooms that tolerate alkaline pH levels, such as certain oyster mushrooms.
In some cases, replace heat treatment with cold chemical pasteurization (particularly for straw or cotton husks) by combining lime and water.

2. Disinfection of the substrate

At high concentrations (typically in a lime-water soaking solution), lime acts as a disinfectant, significantly reducing the microbial load without requiring thermal sterilization or pasteurization.

3. Improvement of the texture and degradation of lignocellulose

Lime can facilitate the breakdown of lignocellulose in certain substrates, making plant fibers more accessible to fungal enzymes.

4. Limestone application

Practical Uses of Slaked Lime

Substrate preparation

Cold lime pasteurization method: The straw or a similar substrate is immersed in water containing 1 to 2% slaked lime (10 to 20 g/L of water) for 12 to 24 hours. The substrate is then drained and inoculated directly.
It can also be used in small amounts directly in a substrate mix, but this requires careful control of the dosage to avoid inhibiting fungal growth.

Dosage

For cold pasteurization: typically 1–2% slaked lime per liter of water.
In a mixed substrate: generally less than 1% of the dry weight, use with caution.

Precautions for use

Corrosive: Slaked lime is caustic; it can cause skin and eye irritation. Wearing gloves and goggles is recommended.
pH too high: Although oyster mushroom mycelium can tolerate very high pH levels, excessively high pH can completely inhibit mycelium growth. It is important to follow the recommended pH levels for the specific mushroom being cultivated.
Not suitable for all mushrooms: some mushrooms, such as shiitake, prefer a slightly acidic pH and do not tolerate high alkalinity.

Organic certification

In Europe, slaked lime is permitted in organic farming for certain uses, notably as a substrate treatment agent or disinfectant, in accordance with the provisions of Regulation (EU) 2018/848 and its annexes.