Anyways, guess what. Even back then this is his casing mix:

2 1/2 parts peat
2 parts verm or perlite
2 parts fine sand
2 parts cruched oyster shell

Now the Magic Mushroom Growers Guide calls for this which is essentially the same.

7.5 litres peat
3.5 litres fine verm.
4 litres fine washed sand
2 litres calcium carbonate

Now this is the only mix I have ever used
and have gotten extremely high yields
and quality tasting shrooms. I also only ever use organic rye grain kernels. You eliminate a lot of the moisture (verm) problems just by using rye grain since when
you sterlize it the kernels swell with water. The only thing I have yet to use is wheat straw/manure. But if you look at any of Stamets books you'll see that the pics of cubies on these substrates are large and densely grown, yummy! So in conclusion, stick with what the experts found through more experimentation than you will ever have time to complete. Sure try playing around with the mix, but don't chop ingredients and then expect the same results. Just my opinion. ; )

I totally agree that vermiculite might have no impact other than moisture on shrooms, but the point that might be missed here is how it's processed. If most people use vermiculite for garden use, the random minerals/ chemicals that are in it from processing steps would just flush out into the ground, however the ways that it is used for mushroom cultivation keep all (if any) extra minerals/chemicals in the cakes, thus they could get "soaked up" into the mushrooms. Thus, my advice, Ripper, if you say that the water that the verm is soaked in gives off a nasty taste, try flushing the verm with some water, get all the extras that are in there out, and make sure all that's left is pure verm. If it is just the verm, and of course vermiculite is insouluble, when you put it into water, there should be nothing else in "vermiculite water" except for water.. but back to my point. Does anyone know how Vermiculite is produced. I think this is key, because who knows if it is exposed to anything other than vermiculte that would make shrooms taste bad or encourage contams. ....I've babbled long enough

-peace

Vermiculite and Health Aspects Associated with
Potential Contaminants:

Vermiculite and other ore bodies can contain a variety of
associated minerals such as mica, quartz, feldspar, etc.
The associated minerals are unique to a particular
deposit and, in some cases, may include minerals which
could pose a health risk if present in significant quantities.
In most countries, manufacturers are required to publish
and make available Material Safety Data Sheets (MSDS).
These sheets will typically identify any hazards
associated with the material and also provide information
on safe handling and proper disposal.
Asbestos fibres are a potential risk to health, and in the
past there has been some vermiculites contaminated with
trace amounts of asbestiform material. Vermiculite ore
bodies currently in use by the major producers, do not
pose a health risk when used in accordance with the
manufacturer's MSDS. However, there are numerous
sources of commercial vermiculite available in the world
today and it is important for the end user to understand
test data from a particular manufacturer.
Such testing should take into account both mineralogical
and morphological differences between asbestos and
non-asbestos varieties of the same amphibole or
serpentine mineral.
Finally, it is important to note that the issue of potential for
fibrous asbestos contamination exists for a wide range of
naturally occurring materials. Included in this list are
materials such as sand, clay, and gypsum. Due to this,
and other studies referencing background levels of
asbestos in the environment, it is inappropriate to state
that any naturally occurring material is asbestos free. Any
reference to trace asbestos levels must include (as a
minimum): analysis technique, detection limit, and
definition of asbestos used in the study.

and from http://www.vermiculite.org/VINA.pdf

Vermiculite ore deposits, like most other rocks, contain an assemblage of other
minerals besides the vermiculite (Addison and Davies 1990). There may be major
components such as feldspars, pyroxenes, amphiboles, carbonates, and quartz, as
well as minor components such as phosphates, iron oxides, titanium oxides and
zircon (Atkinson et al 1982). The full assemblage at any one mine is determined by
the nature of the original rock types from which the vermiculite ores were formed. So
the vermiculites formed from ultramafic rocks such as phlogopite pyroxenites and
serpentinites may contain chrysotile, tremolite and anthophyllite in veins or as altered
relics of olivine, pyroxene and mica. Vermiculite ores formed from gneisses or
granites are more likely to contain feldspars and quartz; vermiculite formed from
carbonates may contain magnesite, calcite and other carbonates, and phlogopite.
The proportions of the different accessory minerals may vary depending upon which
part of the ore body is being worked, and the proportions in the final product may
also vary with the grade of the product.

sorry for the page clutter, but any mad scientist must document his sources...

The general use of vermiculite in gardening is not in large quantities like those used in substrates typically. Vermiculite has been found to contain all sorts of unknowns. When working in a laboratory style environment it just doesn't make sense to use something that can harbor so much!

As far as people bad mouthing peat, I've checked my casings again, its been almost one week since application, with no pastuerization, and I have got no contamination yet. I used the following formula in my casing, I know that the lime that I used is not a very great idea, but the concentration was miniscule.
10 Quarts Peat
20 Grams Chemical Lime(used for curing concrete)
1 Gallon Water
1/4 Cup Hydrogen Peroxide
I sifted the peat in a spaghetti collander first, this took out dirt and sticks, so I was left with a fluffy peat. I used one of the large bags you can get at Home Depot for like $10(Much more economical then Schultz). I mixed the water and hydrogen peroxide in a pesticide sprayer I obtained at Home Depot, it was $10. I then sprayed and turned the peat over and over again, until the gallon of water was in it, it was fluffy, but had a good amount of water in it...

As far as substrates are concerned, we should have some results using straight rye grain in 1/2 pint jars pretty soon. I'll keep you guys informed.

Now that we've determined that vermiculite is a bad idea, we need to start a new thread about ways to avoid using it. I will be compiling information regarding the pros and cons of vermiculite in substrates and casings. What I need from you people is some ideas in this thread, I'll try to post the new thread sometime this week =) Thanks for all of your support regarding this matter, its nice to see you guys thought for yourself and got the facts straight =)

Your original hypothesis being that vermiculite "CAUSES" the bad taste in mushrooms.. (first of all this is subjective and thus improvable) also that it "CARRIES" the cobweb mold... Not just that it is suceptable to it, but that it carries it...

NOPE... The problem is that the vermiculite is STERILIZED... Sterilize your peat and you will have the same problem with it.

It is just susceptible to it the way it comes from the store.. The heat treatment during its production destroys any benifial bacteria that may have been there, as well as the cobweb mold. It just doesn't come from the vermiculite.. The vermiculite is just an easy target in that it holds water and creates a good environment.. Peat would as well if it didn't have bacterias that help defend it against cobweb mold... But if you sterilize it COMPLETELY, and subject it to the same conditions, you will run into the same problem... This does in a way help your ultimate point of why you like peat better, but you are a long way from proving your hypothesis. I think you just don't realize what your "hypothesis" is.

You say :"The general use of vermiculite in gardening is not in large quantities like those used in substrates typically. "

What the hell are you talking about? Bags and bags of vermiculite are used in gardening. YES, SOMETIMES ONLY VERMICULITE!

What am I saying? I am saying your whole Shabang here is ridiculous.. I am not saying it is unworthy of investigation. I am saying you are jumping to conclusions stating things as fact with nothing but speculation to back it up... You seem poised to launch this "Just say no to vermiculite" campain (and it seems to have a lot in common with other just say no campains). Take it easy and try this "thinking" you mention. Prove it with side by side comparisons prepared at the same time, innoculated with the same innoculant, grown in the same terrarium, etc... Then report what you find. Not this Antivermiculite propaganda. I personally don't care one way or the other why you have this intense hated of the demon vermiculite, but I just can't stand propaganda with a spoonful of "think for yourself"

ThE JafF

Not that I expect that anything of the sort will be done properly... I certainly won't waste my time on it. It seems analagous to a huge clinical trial to prove why pint jars are better than 1/2 pints when I am perfectly happy with the results of 1/2 pints. Yet I don't find defending poor vermiculite from the propaganda machine to be a waste of time. I will always enjoy the fight against the propaganda machine..

ThE JafF

[This message has been edited by ThE JafF (edited February 15, 2000).]

------------------
-From a registered Mad Scientist

"From a certain point of view"
-Jedi Master Obiwan Kenobi (also a Mad Scientist tm)

ThE JafF

Glad to see your still around, Ripper. I read your goodbye post and it saddened me. I didn't keep up with the problems you cited for leaving, but gathered that it was some personal problems with people at the shroomery. It sucks to loose intelligent people that have much to offer just because some have to be assholes.

Now that you're back, lets do what we're here to do: learn, teach, debate and improve the world of closet mycology. For it is in the closet that the most innovative ideas in mycology originate.
peaces

------------------
-From a registered Mad Scientist

"From a certain point of view"
-Jedi Master Obiwan Kenobi (also a Mad Scientist tm)