If you want to learn how to grow mushrooms in bulk, that is cost effective, and easy, then this is the tek for you! Update April 2018: A grow kit has been made for this tek, if you want to skip all of the hard labor of creating and sterilizing your own grain spawn and substrates, and have someone who has been doing this tek for more than 10 years make it for you, order the grow kit here from Mycology Kits online store: https://mycologykits.com/shop/grow-kits/dub-tub-grow-kit/ This technique is nothing new, it has been used by mushroom cultivators for a long time. It is one of the simplest bulk applications that there is, and is great for anyone who wants to learn how to grow shrooms. I hope that this information will expand your mind as much as it has mine, for many years to come. Lets start with the basics:   Linked from how to grow magic mushrooms Things you will need before you can begin:   Number one: Spores to grow your mushrooms (buy these from a trustworthy source!!) I cannot stress how important it is to buy from only the most reputable sources. If you mess up here, you WILL FAIL no matter how hard you try on the rest of the steps of this tek. If you like Shroomology, and you like my tutorials that I have shared with you PLEASE SUPPORT OUR SPONSORS! I recommend buying your spore syringes from sourceofspores.com (our sponsor for mushroom spores) You're going to need as many as you can get if it's your first time. You'll probably mess a few or 5 up. I'd tell you about my first time growing and how many I messed up, but that's off topic. Let's just say if I hadn't of bought 7 spore syringes, this tutorial probably wouldn't exist. Because I screwed them all up but one.  See reviews of source of spores here Keep in mind that most spore vendors sell their products for microscopy use. Don't mention growing at all or this page when or if you communicate with them, or they wont sell them to you. Remember, have some common sense! USE COUPON CODE "SHROOMOLOGY" for a discount on your entire order at Source of Spores! You're welcome! Other things you will need:   Quart sized mason jars about $9 at wal mart for 12 (I recommend 24 jars to start) 6 quart "shoe boxes" tubs $1 at wal mart (2 tubs for each tub set up) Pennington Classic Wild Bird Seed (or similar) about $8 at wal mart 5 gallon bucket with lid Pressure cooker (at least 16qt PC) Tyvek Envelopes from the post office FOR FREE Micropore Tape (cloth medical tape) Butane Lighter 70% rubbing alcohol Coco coir (sold at pet stores that sell reptiles DO NOT GET THE MULCH KIND) Gloves face mask aluminum foil COARSE grade vermiculite spent coffee grounds nail hammer Silicone or RTV high temp silicone pot to boil 1 gallon of water in   STERILE TECHNIQUE:
I will first touch base on sterile technique. i wont go all out with explanations and steps, as its all pretty much common sense. I will say, dont be a freak about it, or mix chemicals and burn your face off. Fumes are bad mmkay? However, This is an important step that should be considered as part of every step of this tek. Some steps require less sterile technique than others, sure, and you will learn that as you get things down, but for now lets say its mandatory for success that you observe sterile technique through all of your procedures until you do. Contaminants to the mushroom culture are public enemy number 1! These contaminants are competitor molds and bacteria that can and will overtake the mycelium that you are attempting to cultivate, if proper sterile technique is not observed. That is not to say that you will have a 100% contam free experience every time you cultivate mushrooms.. Contams happen to even the best of us. So some basic sanitation procedures:First understand that you, as a human, are a walking, breathing, contaminant to your mushroom culture. You must take precautions to sanitize yourself. Before doing any work that requires extreme observance of sterile technique, take a shower, brush your teeth, and use antiseptic mouthwash. Put on freshly laundered clothes, if you are going to wear clothes at all.

All work areas must be clean! Clean surfaces with 1:10 bleach to water solution, rubbing alcohol, Lysol, oust, or any other product that kills molds AND bacteria! Sanitize the air with Lysol, oust, rubbing alcohol, etc.
Wipe all tools etc with 70% alcohol before each use, and that means right after you use them too
Wear protective gear like gloves, and dust masks.
That said... Use common sense!


Note: This section must be completed before moving onto any other section entirely

The type of grain spawn that we are going to use to grow mushrooms in this tek is Wild Bird Seed or WBS for short. WBS is cheap, and can be found at wal mart or hardware stores. Try to steer clear of WBS that contains cracked corn in it. Cracked corn sucks and turns to creamed corn. Not good.


Beyonds easy tyvek lids
These are the best lids you can make for your spawn jars. The tyvek works great as a contamination barrier, and it is free at the post office, plus there is no guessing as to where to stick the needle in! The rtv acts as a self healing injection port (S.H.I.P.) so there is no need for micropore tape.


A good glovebox will make success rates in this hobby skyrocket, although with the type of lids that we use in this tek, a glove box is not necessary. A good glovebox is a box that when sealed up is air tight to nearly air tight, and has gloves attatched to sleeves, that are attatched to the box in some practical way. I use the shadow box. It costs about $30-50 dollars to make but it is well worth the cash. You should find a glove box that works for you, and use it.

We have two of these here at this moment of writing. Both of the glove boxes are awesome.
Shadow box version 2.0
High Quality Glovebox by Str0be

Wipe your needle with alcohol before and after you noc any jar.
Wipe your lids with alcohol before you stick the needle through the tyvek.
Cover holes with micropore tape, to keep contamination out!

Inoculate the WBS by sticking the needle in the jar through the ship, aim the needle at the glass side of the jar, then squirt just a little onto the glass side of the jar. Try to make about 4 inoculation points in each jar by squirting a little spore solution in 4 places of even distance apart from each other.

Use 1cc per jar.

Set in incubator @ 75-80* F If you do not have an incubator you can use a cardboard box on top of your refrigerator

It can take up to 14 days to see growth from spores.


When the mycelium has colonized about 20-25% shake the crap out of the jar to redistribute the colonized grains around the jar. This will speed up colonization immensely.

Time to shake!

Pic courtesy of Str0be! Thanks!

Once your jars are 100% and it is time to spawn you can begin your sub prep!


NOTE: This section can only be completed once section one is complete and the grain spawn jars are colonized 100%


Brick of Coco Coir
Spent coffee grounds
5 Gallon Bucket
Oven Bags (optional)

Coco Coir will be the substrate that you spawn your colonized wbs to. You will be adding the spent coffee grounds to add nutes to the coir. Coir does not contam as easily as other poo based subs, so it is a good bulk sub for the beginner.

Add spent coffee grounds @ 1 cup per brick of coir.

1 Brick of coir should make about 4 6qt tubs worth of sub, so use 1/4 brick per tub.

1 Gallon of boiling water is required to expand and hydrate the brick of coir, so use 4 cups boiling water per 1/4 brick.

Bring water to a boil, put coir, and spent coffee grounds in the bucket.

Slowly pour boiling water over the coir, then place the lid of the bucket on, or use a towel to cover the bucket. Let it sit for about 15 min, then stir it up so that its all broken up and fluffy. Re-cover the bucket and let it sit until the coir is cool enough to work with.


At this point your coir can be used as a sub. The hot water, and steam has probably killed off anything malicious living in there. But this is not gauranteed. So here is your choice. You can either use the coir straight from the bucket, and spawn to your sub, or you can load it up in an oven bag and pressure cook it to make sure that it is sterile. I recommend PCing it, just for optimal success rates. Just sayin... Now back to the sub prep:

When the coir is cool enough to hold, grab handfuls of it, and wring the excess water out of it so that it just barely dripping.

You can either load that field capacity subtrate straight into your tubs, or into an oven bag. If you decide to load it into an oven bag, you will need to squeeze the excess air out of the bag, seal it with the ties provided, then poke two holes in the bag, and cover those holes with micropore tape, so that the bag does not swell up in the PC and block the vent pipe.

Let the substrate cool completely to room temperature, and you are ready to inoculate your bulk substrate with colonized grain spawn.



As with every step you take in this hobby use proper sterile technique and common sense.

Wipe your tub out with alcohol, and while that is drying cut yout black trash bag to cover the bottom, and the walls of the tub.

Line the tub with the black trash bag, and dump 3 qts of sub into the trash bag, then dump 1 qt of 100% colonized spawn on top of the sub.

Mix in the spawn and sub very well, making sure to get spawn all over the bottom and in the corners of the trash bag. Break up any clumps of spawn as best as possible with your hands.

Once thoroughly mixed make the sub as flat as possible without packing down the substrate. You want the sub to be light and fluffy so that the spawn can run the substrate easily, and quickly, but flat for proper pinset.

Cover the tub with foil well, making sure there are no leaks around the edges.

Poke a few small holes in the foil for gas exchange, and cover them with micropore tape.

Incubate the substrate at 77-80* F

The incubation, and colonization period of a bulk substrate is known as the "spawn run." During the spawn run DO NOT MESS WITH THE TUBS OR "CHECK ON THEM" FOR ANY REASON unless you smell something very foul coming from the area that the tubs are in. Allow at least 6 days for the myc to run the substrate fully. Mycelium needs very high levels of c02 to colonize properly, and if you peel the foil back prematurely, not only are you asking for contamination, but you will be reducing c02, which will most likely increase colonization times.

This is what the sub should look like 6 days after putting this sub in the IC:

Could be better if the spawn is allowed to run for 10 days     SECTION THREE: CASING LAYER, FRUITING, AND DRYING     50/50+ CASING

CRUSHED OYSTER SHELLS (chunky kind) ((optional))

A casing layer is a thin layer of a non-nutritive medium, in this case mostly sphagnum peatmoss, that will hold a lot of moisture for the developing mushrooms to utilize. After the spawn run you will want to apply your casing layer to stimulate a decent pinset, and protect the mycelium from drying out in the tubs (this is not optional). Casing depth should be 1/4".

This is a 2 qt recipie which should be good for about 3-4 tubs if cased 1/4" deep:

1 qt. Sphagnum peat moss
1 qt. Vermiculite
4 TBSP lime
1 cup crushed oyster shells
2 cups water

First add all the dry ingredients together, and mix them up well.

Then add the water, and mix well again

This is what the PH should be about:

Load this up into jars, or an oven bag, and PC for 60-90 min.

Case the tray by putting 1/4" of casing material over the surface of the substrate as evenly as possible. Once this is accomplished mist the casing, and the walls of the tub, and the top tub. Install the top tub.

Fruiting the mycelium successfully will only happen if several environmental factors are present at once to stimulate primordia formation. Those factors are:

Temperature reduction
Reduction of C02
Evaporation from the surface of the substrate
Exposure to light (minimal)

Temp range is anywhere between 68-80*F. However the hotter the temp, the more hollow the stipes. For quality mushrooms fruit at temps of 68-72*F.
  Mist and fan at least 3x times a day. Misting consists of GENTLY misting the casing and misting the walls of the tubs including the top tub. When fanning, fan the casing for at least 60 seconds vigorusly. Make sure not to use water with chlorine or other chemicals. It can cause bruising on the mushrooms and mycelium. Use distilled water preferably.

Another pinning strategy, which is much more time consuming, but very awesome is this one:
Here is a fanning set up with this tek:

Mycelium and mushrooms do not use light like plants do. Instead light is used to determine which way to grow in some species. For those species we use either natural day light, or 6500k "daylight" bulbs. light does not need to be intense, just natural diffuse daylight works great.       PINSET
And now the part everyone loves. about 7-14 days after you set the tubs into fruiting conditions you will start to see pins pushing through the casing. Dont lose it though, continue to mist and fan.

Harvest the mushrooms before they begin to dump spores all over the place. Generally people harvest right before the veil breaks, or right after. To harvest gently grab the base of he stipe, and twist to the left and right until the mushroom separates itself from the sub and casing. Do not rip them out. Remove all mushroom matter from the casing. Bring some kind of bin or tote lid with you to put the mushrooms on.

Spore Printing
Spore printing is important, if you wish to preserve your strains, for future use.

How to make a spore print

After the harvest you will want to dunk your sub. Set something heavy on top of the sub, then pour water in the tub until it is submerged. Leave the sub submerged for 24 hours. After 24 hours dump all the water out, and set the sub on something to drain for 30 min, the reintroduce the sub to normal fruiting conditions.

There are several techniques to drying mushrooms. This is how I do it (fast forward to 4:20):