Visa, Mastercard, Discover, AmEx, Paypal, Bitcoin, Money Order $

Twitter logoTweets

Please visit our friends at
for all your gourmet cultures and SPORES!
Posted March 24

HOT!!! NEW LIMITED EDITION T-SHIRTS! Only 45 printed! Dope new design! Click here!
Posted December 21

Now accepting BITCOIN!
Posted January 15

Now shipping to CANADA!
Posted October 14

Pre-Pasteurized Mushroom Compost

Starting at: $5.95

Please Choose:

Pre-pasteurized premium bulk substrate mushroom compost in a gusseted autoclave bag with filter patch. Shroom Supply mushroom compost is specifically formulated for growing mushrooms. It is free of any additives or chemicals and is to be used in conjunction with our mushroom grain spawn.

This choice bulk substrate is composed of five main ingredients including an organic compost specifically designed for mycological use, composted horse manure, organic coconut coir, vermiculite, and gypsum. This diverse blend of unique ingredients provides the perfect amount of nutrition for optimal mycelial growth, making it the ideal growing medium for mushroom cultivation.

Our premium mushroom compost comes pre-pasteurized and hydrated to the perfect moisture content, making it ready to use right out of the bag. Simply add colonized grain spawn, mix, and add to your fruiting chamber or grow bag. We recommend using two pounds of our grain spawn for every five pounds of compost. Once the substrate is fully colonized with mushroom mycelium, our casing mix can be applied in a thin layer to the top of the substrate. Please note that a casing layer is not required, but rather an optional ingredient that can benefit the growth of certain mushroom species.

This product comes heat-sealed in sterile, filter-patch mycobags and can be stored at room temperature for up to 14 days. If more time is needed, it can be stored in the freezer and dethawed before use.

All mushroom compost comes packaged in 5 lb. increments.

Made to order, usually ships within 2 business days.

Instructions: Bulk Substrate Tutorial

View All    [<< Prev]   1  2  3  4  5 ...  [Next >>] 

Tyson Iossi
5 of 5 Stars
This stuff is AMAZING! I got 6 and even 7th flushes before I decided to throw it out just to make more room. It was still producing a few mushrooms even on the 6 and 7th flush. Everything I've received from other vendors has always contaminated after the second flush and many times before that. Look no further, this is the best substrate you will find. It gives you the best possible yields with the most flushes, everytime! Thanks for making my job so much easier.
5 of 5 Stars
Great product and service. Faster colonization and better pin-set than any compost or pasteurized straw ive made. Cant beat pre pasteurized. Thanks guys
5 of 5 Stars
I barely started cultivating and having failed using the PF tek and also using monotubs, I have successfully harvested an abundance of fruits using this substrate. A+ rating, definitely worth every penny..
5 of 5 Stars
This stuff really is worth every penny, I mixed 1000 lbs of substrate and cooked 5 bales of straw this week. Id say this product outshines and outlast and outpreformes my attempts for 2 years consistently "Shroomsupply's Substrate has never contaminated on me". We got 4-5 flushes over 2 months with shroomsupplys I threw away half of homemade attempts, never thrown away SS's bulk sub's js
c pa
5 of 5 Stars
Have only used this since I started growing. & successful every time. Will be a return buyer.
5 of 5 Stars
Just spawned so I don't know about contams yet, but I'm the farthest I can be from the state they ship from and it still got here in 3 days. Very good primo poo. I'm sure the little ones will love it.

View All    [<< Prev]   1  2  3  4  5 ...  [Next >>]