I am posting this write up in order to share with everyone just how
easy it is to properly pasteurize a substrate. This is the method that
I use to prepare pasteurized coir/coffee substrates for my edible and
medicinal experiments, but it can easily be adapted to just coir/verm,
horse/cow manure, or whatever your substrate mix of choice is. I got
my methods from watching how a few other members go about preparing
substrates, the biggest influence being Prof P. You can find his video
TEK for making poo based substrates below:

http://www.shroomery.org/forums/showflat.php/Number/14425853#14425853

You Will Needed:

-Ingredients for substrate
-Plastic bags that will withstand boiling temperatures (I use 2mil polypropylene bags)
-Zip ties
-Meat/Candy thermometer
-Micropore Tape (any tape really)
-Scissors
-Knife
-Large Pot with lid (or that can be covered with a dinner plate etc)


Step 1 - Preparing Your Substrate

First prepare your substrate mixture. Here I have some coir/verm that
I am bringing to field capacity. I am not including measurements because
this tek is more about proper pasteurization techniques then actual
substrate composition. In this mix I have included coir/verm/gypsum/coffee grounds.


I first mix my dry ingredients and then add water until I reach field
capacity. Field capacity is achieved when you squeeze a handful of your
mixture and only a few small drops of water drips from your hand.


Next I add my coffee grounds as this mixture will be used for some
king oyster experiments and oysters do not tend to do well on just
coir alone. Adding 30-40% coffee grounds to your coir mixture (for oysters)
will give you better results, but still not the best from my experience.

After fully hydrating your substrate take it and load it into as
many bags as needed. Note that the larger you make your bags the longer
it will take to get the internal temperature high enough to reach pasteurization.
For that reason I prefer to split my batch into two bags.


Zip tie the bags closed close to the surface of the substrate and then
cut off the excess tie and a bit of the bag as show below.


Now you are going to make a re-enforced port to allow your thermometer
to be inserted and removed. I use micropore tape here, but you can use
any kind of tape you have handy and just place a strip over the top
of the bag high enough that no water will enter through it. After you
have placed the tape on the bag take a knife and cut a hole in the
center.


Step 2 - Pasteurizing
Fill a large pot about 1/4 to 1/2 full of water. Place it on your stove
top and load your bag/bags into the pot so they are sitting on the
water and the hole you have punctured will not take in any water.



Set your stove to medium heat and allow the water temperature to rise.
You can check from time to time with your thermometer to see what
the internal temperature of your substrate is.

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****IMPORTANT NOTE****

Sadly most thermometers are sharp and meant to be stuck into meat or
other food products and the bags we use are relatively thin and easy
to puncture. This makes for a combo that can easily ruin your project.

When inserting your thermometer try to be careful not to come close to the
bottom of the bag as doing so can easily peirce the plastic which will
allow water to seep in. This will over hydrate your substrate as water
migrates into your bag through the holes.

What I like to do is insert the probe so it runs lengthwise into the
core of the bag, that way I can get an accurate reading without having
to worry about peircing the bottom of the bag.

A few more things you can do include:
-Using two bags for your substrate. This will help give a bit more strength
to the bag, but it will also take longer to heat your substrate upto
temperature.
-Place a small strip of micropore or other tape along the tip if your
thermometer to dull the point

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Allow your substrate to climb in temperature to about the 130-135F
range. At this point you will remove the pot from the burner and place
a lid/plate on top of the pot to keep the heat inside of the vessel.

The temperature of your substrate will then climb into the 140-150F
range as the heat is being contained in the pot. This is the pasteurization
range and must be maintained for around 90 minutes. As long as you
have either a tight fitting lid or other means to keep the heat in
your substrate will keep above 140F for 90 minutes no problem.


I walk away from the pot and set a timer for 90 minutes, at which time
I will come back and remove the bags from the pot. After drying the
bottom of the bags I allow them to cool further. Once fully cool I will
use clean grain spawn to inoculate the bulk substrate in a filter patch
bag, seal it shut, shake, label and date.

This method allows for proper and true pasteurization every time,
with minimal efforts. For larger batches of substrate this can be a
pain in the ass, but for what most people need this method will work
perfectly.

Now some people will ask why not just use D's coir tek? While D's
coir tek is a great method it is not true pasteurization. Using the
materials that he suggests 95+% of people will have great results,
but others will have issues with contamination due to partial sterilization
of the substrate, adding items that need proper pasteurization(coffe,
manure, etc) or factors relating to the persons environment.

Well folks I am off to spawn some king oysters to my coir/verm/gypsum/coffee
mixture, and I hope you all are ready to fire up your pots!

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truskool said:
Another awesome tek EM

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truskool said:
99% of the teks written nowadays are re writes anyways

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Lifted1 said:
Ok so, adding gypsum and worm castings to that bucket tek would possibly create problems?

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gypsum no, worm castings yes. 

gypsum / verm are minerals so they are pretty contam resistant. 

everything else thats not a mineral needs proper past.

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billb said:
If you do more then one bag at a time, can you assume that the bag without the thermometer will be the same temp? also, does each bag need a "breather" hole?

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if you take temps from the center most bag then its safe to say the outer bags are up to temp also

bags swell, they need to breath