Using the hydrated lime bath method successfully dispense with the pasteurization or sterilization steps in straw preparation.
Mushroom growing requires several essential steps including pasteurization or sterilization. Pasteurization or sterilization is often the most expensive step because it requires fuel-consumption for steaming or boiling.
Though this is important for obtaining high yields, it is a very tricky and labor-intensive process. The good news however is that, mushrooms could be cultivated without pasteurization or sterilization. In this case, the whole process becomes much easier, faster, and less expensive.
Natural sources such as lime stone and pulse powder are used to successfully dispense with the pasteurization or sterilization process. This method; using the hydrated lime bath can help you save energy costs plus it has been tested over the years with good results.
Ingredients and material
- Wheat Straw (Chopped)
- Lime Stone (CaCO3)
- Pulse Powder: (1k) Wheat Bran or (4k)if using Rice Bran
- Water: 100L or more
- Polythene Sheet (optional)
- Bricks (or a paved clean floor)
Procedure for Hydrated Lime Bath Method
Pour water into a large container or drum and add a desired quantity of wheat straw and leave until the wheat straw is soaked.
Fill 100L of water into another container and add 5kg of lime stone to another container and let it dissolve. The dissolving lime emits heat and gases. Add the soaked wheat straw to this solution.
Lime stone acts as an anti bacterial agent and kills all the viruses harmful to the initial growth of the mycelium. It also lowers the acidity of the wheat straw which is not good for the growth of the mycelium.
Take the soaked wheat straw out of the water to mix with your nutrient/ additives of wheat bran or rice bran. Mix them thoroughly on a clean floor with a polythene sheet on it.
Make a closed tray pattern on the clean floor with bricks in a circular shape. Spread the remaining 10kg of dry lime stone inside the circle of bricks. Pour the soaked wheat straw mixed with wheat bran on the lime stone layer. Pour in water until the base gets wet to speed up the chemical reaction of the dry lime stone. By this chemical reaction a lot of heat and gases are produced which are helpful in pasteurizing the material.
Quickly cover the substrate with a plastic sheet to keep in the heat and humidity for 24 hours. The substrate should be covered no longer than 24 hours. The substrate is ready for spawning the next day. After 24 hours, move the substrate to a shelf, tray, or bags for spawning If you’re using shelves or trays;
Cover the all the shelves tightly with a plastic sheet in order that no air can enter and so the required humidity level is maintained. After a week, the mycelium starts growing and spreads all over the shelf.
During mycelia growth, keep the temperature of the room at 10-15 degrees for the best results and to provide the most favorable environmental conditions.
About 50 days later, the whole shelf will be colonized with a white milky color by the mycelium. The wheat straw mixture is no longer seen. Remove the polythene sheet from the top of the substrate and induce pinning.