These are Treasure Coast spores from PF.
I took a fully colonized cake,
cut it in to 4 equal parts, and then
cased the broken up cake quarters.
Each one of thoes pans only has 1/4th
of a cake in them.
Simply put, a yield of 1 lb. of fresh mushrooms from 1 lb. of dry substrate is considered to be 100% Biological Efficiency. Since mushrooms are approximately 90% water and the base substrate is typically raised to 75% moisture, 100% Biological Efficiency is equivalent to saying that 25% of the wet mass of the substrate is converted into fresh mushrooms.
Although such yield efficiencies are commonly achieved by experienced growers, many choose not to "chase the optimum", as their growing rooms can be better utilized by cycling in fresher material.
With some simple math and a little analysis, it can be readily seen that PF substrate is well over 100% "Biological Efficiency". RipSnort reports that his Treasure Coast shroom fruiting was had by quartering a PF cake and using the 4 pieces in seperate containers in which the quartered pieces were cased. This means that each fruiting tray above contains about 1/16 of a cup of brown rice powder and about twice as much vermiculite, plus the casing.
In a normal PF 1/2 pint cake, there is about 31 grams of brown rice powder (1/4 cup) and about 17-20 grams of vermiculite (1/2 - 2/3 cup) which adds up to about 50 grams dry weight. It can be conservatively stated that a properly cultivated PF 1/2 pint cake can produce (with several flushes) at least 10 grams of dry shrooms (100 grams wet weight). By using the above biological efficiency formula - this equals an easy 200% biological efficiency for that 1/2 pint PF cake (50 grams of dry substrate producing 100 grams of wet shrooms is twice efficiency - the wet shroom weight is twice the weight of the dry substrate, or in other words - 200%).
This amazing ability of cubensis shroom races to fruit on PF substrate has made the PF TEK the new fundamental of cubensis shroom cultivation. The PF TEK can be used straight PF style (mini culture) to get great fruitings of diverse cubensis races, or can be utilized in more mega style cultivations with trays or larger containers with more massive substrate amounts (compared to PF style Mini culture). What is being demonstrated at various mycophile web sites is PF substrate being mixed with various grains, soils and substrates with impressive fruitings on display. A certain percentage of PF substrate with any kind of cubie substrate results in big fruitings. AND, when PF substrate is used in these mega cultivation teks without the additional grain, fruitings are just as good, if not better. The RipSnort Treasure coasts are proof of the magic of the PF formula (brown rice powder and vermiculite).
Then in late October 1981, PF attended the Paul Stamets and Jeff Chilton Myco Media shroom conference at Orcas Island Washington. During a Stamets lecture, Stamets mentioned mixing vermiculite or perlite into grain substrates to get a better and easier shakeability. It was like a lighting bolt that hit PF, as he busily scribbled down some notes about this substrate mixing concept.
PF went home and began a series of experiments combining these two ideas (Pollocks rice cakes and Stamets vermiculite mixtures) which resulted in the PF TEK magic substrate formula, which has become the new fundamental magic mushroom growing and culturing medium.