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50/50+ Casing Tek

Ryche Hawk's 50/50+ casing tek version 3.1

Here is a real easy casing mix that works great for cubensis, panaeolus, and other species. Our growers and people worldwide have had great success with this very easy casing method.

At the end of this document, look and read the updated 50/50 (PLUS) Casing Tek. We highly recommend the 50/50 tek over any other casing tek out there. The addition of limestone and crushed oyster shell to the 50/50 mix makes a huge difference.

We suggest using plastic trays. You can buy ones at Home depot that can be cut and taped to any size you want. Look in the gardening section by the seedling transplanting trays. They are long, black and thin. They can be cut and taped very easily. If you can't find these trays use anything that will fit to your aquarium size. The idea is to get the best non-transparent (see through) container you can find in the space you have to work with.

You can cut and tape these to fit the exact size of the bottom of your aquarium, leaving about a 1/2" space around your trays so moisture drips down the sides of the glass and not into your tray. You want to use plastic tape and not masking tape or it will fall apart when it gets soggy. You also want to use trays that are black or non transparent so light doesn't seep through to the substrate below or the mushrooms may fruit from under the casing layer and up the sides of the casing instead of on top of the casing layer where they should.

OK, now the fun part!

  • Take vermiculite, first mix in a bowl with water until its real moist, squeezing out any excess water.
  • Then drop about 1/2" layer across the bottom of your container.
  • Then take fresh cakes from the jars, cut them like a cucumber into slices about 2-3" thick, or for best results leave them whole.
  • Put these slices over the layer of vermiculite. Take some colonized substrate and gently crumble to fill in the places in between the the slices of substrate. This is so your entire layer of substrate is pretty much filled without gaps between the slices or the sides.

We recommend cutting out any uncolonized part of the cake/substrate first. What you'll have left is 100% colonized substrate. If this does not apply, then move to the next step.

Next, take a mixture of 50% peat moss and 50% vermiculite, sterilized or pasteurized (more info on that at the bottom) real moist, once again squeeze out excess water, then just lightly place it over the mycelium layer, about a 1/2" to 3/4" just so it covers the mycelium layer. You can also use a little deeper layer, about 3/4" to 1" to allow for a stronger casing layer that will be helpful for more flushes. The downside is it takes a little longer to colonize and fruit. Although in the long run it is well worth it. Only use the 1" thick casing layer if you're using whole cakes or a deep substrate.

Your substrate depth should be no more than about 4" thick. Put your container back in your aquarium right on top of the perlite. I would recommend keeping the light off for the first week, but even leaving it on for 12/12 will not make that much of a difference.

Within about 2 days you'll start seeing the mycelium overtake the casing layer, you want to add a light amount of 50/50 mix over these first high spots so all the mycelium is coming to the surface around the same time, although this is not written in stone.

Within a week to 2 weeks it will be almost completely covered in mycelium. Then the mycelium will stop growing for a few days. The mycelium network is establishing itself, becoming stronger and stronger preparing to produce mushrooms. Then pinning will start. You will begin to see lots of bright white small dots about the size of a pen head. These will form into mushrooms soon thereafter. Harvest time is usually 10-21 days after casing.

As a general rule you do not want to mist your casing during this colonization period, provided you have adequate humidity and fresh air. The ideal humidity for casings is 82% -92%. The reason you don't want to mist your casing soil during this period is because water condensation build up on the mycelium is not good. It will slow down the growth of the mycelium and possibly introduce contaminants easier.

The mycelium will pull most if its moisture from the casing soil itself and from the humidity in the air. Ideally, you should try and harvest your first flush all around the same time, or within a 24 hour period. Then put a light sprinkling of 50/50 mix back over the spots where you pulled the mushrooms from. You want to put down fresh casing in those places where you pulled the mushrooms from to help protect that substrate below. Make sure the casing soil has been sterilized or pasteurized. The reason you want to try and pull all the mushrooms around the same time is that this will help the mycelium network recover faster and prepare for a second flush.

You want to start misting again after you have harvested your first flush. Give it a real good heavy misting so the soil looks moist again, but not saturated. You shouldn't need to mist again until after the next flush, and so on. Now this is not written in stone. This is only if your growing conditions are ideal. Growing outside can be different, you may need to lightly mist the soil every few days because the soil dries out faster. So the rule to follow is if your casing soil looks real dry (starts changing color and getting a real light dried out soil look) then go ahead and give it a light misting. Also, if the casing soil has started pulling away from the side of the container, put in some fresh moist casing soil in there. After the first flush you can look forward to your next flush in about a week.

You will get huge flushes from this method. If somewhere along the way you start to see contamination in any part of the soil, cut it out immediately, making a big cut several inches away from the contaminated part. Putting down a big fresh spot of casing soil where you cut it out. Its pretty typical for casings to get hit by the green mold Trichoderma after a few flushes, but by keeping your hands, arms and tools clean, by wearing a face mask and using fresh sterilized soil for patches, this will help prevent it from happening too soon.

50/50 (Plus) Casing Tek

Adding 4% agricultural hydrated lime and 15% crushed oyster shell, by volume, to the over all 50/50 mix is a much better casing soil. The soil seems to give the mushrooms more support so when your harvesting your not digging out deep chunks of mycelium from the substrate, instead they pull out very easily from the surface. The mushrooms also seem to grow much bigger this way being they have a stronger base into the mycelium network. They also like the lime and calcium from the oyster shell, and you will see less contamination in the casing soil with the lime added. When mixing the casing substrate, a lot of the oyster shell and lime sinks to the bottom, so mix it and squeeze it real good when placing over the substrate.

Be sure you buy horticultural hydrated lime, not dolomitic or other kinds, or it will burn the mycelium and they wont grow. So look at nurseries for horticultural hydrated lime, it usually says "to sweeten the soil on the bag".

Although most people, including us, have great success from using horticultural hydrated lime, some do not. They end up burning their mycelium or the mycelium just never colonizes through to the casing soil. We think perhaps the hydrated lime they are buying has a much higher alkaline level then then the Hi Yield brand we are using. Hi Yield brand is our preference and works great for us. But just to play it on the safe side, we are going to suggest you buy calcium carbonate. A ground calcium carbonate is a gentle buffer. Some brands of hydrated lime are not. Calcium carbonate is basically ground up limestone, a soil sweetener. It works just as good if not better then horticultural hydrated lime. Its a much safer bet as well. You should be able to find calcium carbonate in just about any garden supply store.

Another tip, look for the large chunked oyster shell sold at feed stores. The fine powder shell is fine, the but the large chunked shell gives a much better texture and the mushrooms grow even better on this soil. You can find oyster shell anywhere birds are sold, or at most feed stores.

The exact mix, to fill a filter patch bag 3/4 full is:

  • 15 1/2 cups vermiculite
  • 15 1/2 cups peat moss
  • 4 1/2 cups crushed oyster shell
  • 1/2 cup or less of hydrated lime
  • 15 cups of distilled water (1 cup short of a gallon of bottled water) 16 cups = 1 gallon

This will make enough for a good 3-6 medium to large casings depending on how big they are.

Tips on sterilizing and pasteurizing substrate:

There has been a lot of discussion on whether it's better to sterilize the casing soil or not. In my friend's studies, he has found that sterilizing is better. Some people like to pasteurize it. That's OK, but he prefers to sterilize it. My friend buys filter patch bags from Myco Supply or Fungi Perfecti or various other vendors. These are large autoclavable bags (meaning they can go in the pressure canner and survive the heat without melting) with a filter on them for gas exchange. Although for sterilizing the casing soil, the patch does not matter. Basically after mixing up all the dry ingredients, (pulling out all the sticks from the peat moss) for the 50/50 mix, add in your water. Mix really good, have your filter patch bag handy, squeeze out most of the water from the casing mix. Squeeze so its just slightly dripping then put it into the bag. Fill the bag about 3/4 full. Put this in your pressure canner and be sure to keep it away from the sides of the pressure cooker. Sometimes the filter patch bag will melt if it touches the sides. Sterilize at 15 p.s.i for 45 minutes.

Let this completely cool before using. Now at this point, the pressure cooker is going to take out some of the moisture. Just make sure when you go to use it as your casing soil you squeeze out the water until its barely dripping and not running water. Here is another strange kicker, my friend puts his bag outside... in the shade... with the top folded/rolled down with a plate on the top to hold the bag shut so that no bugs can fly in. He lets it sit outside for a few days or weeks before using it. When you sterilize it, you're killing any eggs of larva or other unwanted bacteria in the vermiculite. You're actually killing more in the peat moss, well.. this is only his theory, no scientific data to support this, but... by putting it back outside, it regains some of the needed micro organisms' that the casing soil lost during sterilization. Now perhaps his theory is right, or perhaps he's just been lucky... but he has seen a lot less Trichoderma hit his casings since he started doing this.

Another important note, when the time comes to use the soil make sure the moisture content is correct.

  • If too moist, squeeze the water out until its barely dripping.
  • If too dry, then add in some bottled mountain spring water then squeeze it back out.

Another tip, if you don't have the resources to buy the filter patch bags, the plastic bags that the peat moss and vermiculite come in also work fine as well. Just cut the rubber zipper seal off of them so they don't melt and use them the same as above. Just make sure you keep them away from the edge of the cooker.


Use a layer of 50/50 casing tek as the bottom layer instead of plain vermiculite, it works better.

If you don't own a pressure canner/cooker then pasteurize this mix. You pasteurize by putting the casing soil inside, say an old pillow case, twist and tie up the top so that no casing soil leaks out. Then put it into a pot of water. The water temperature should be around 150

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