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Chemistry Forums for Students => Inorganic Chemistry Forum => Topic started by: edevils on February 07, 2020, 01:01:22 PM

Title: Pasteurization of Mushroom Substrate Using Calcium Hydroxide
Post by: edevils on February 07, 2020, 01:01:22 PM
Hello and thank you for reading this post!!

I'm an amateur mycologist.  One of the methods to grow oyster mushrooms involves the pasteurization of straw.

In order to pasteurize the straw, you need hydrated lime. "You basically just soak straw for 12-24 hours in a bath of cold water that has been treated with hydrated lime."

Most of the "lime" I'm seeing at big box stores is calcium carbonate lime.  This type of lime contains magnesium which will harm the mycelium. However, I did find calcium hydroxide in concentrated form (HiMedia GRM718-500G Calcium Hydroxide, Purified, 500 g) on Amazon.

The pasteurization process calls for "6 grams per gallon of water used".  The hydrated lime used in this process is typically in 40 lb bags for masonry or agriculture.  How is the powdered lime in bags different than the purified product listed online?  Would I just do a one for one and use 6 grams of the calcium hydroxide purified powder for one gallon, or is it not that straight forward.  I'll leave links for the product and for the mycology page below.

https://tinyurl.com/vl4j8m5 - this is the website with the pasteurization process
https://tinyurl.com/rkrqcp5  - this is the product manufacturer's website
https://tinyurl.com/t9b7q2q - this is the amazon listing of the product

Thank you so much!