Submitted by Deviou5
PF Tek is a term that has been around in mushroom cultivation for a long, long time.
I’ll skip the history lesson, but I will quickly describe how it works in case you’re unfamiliar:
The technique involves packing wide-mouth half-pint jars with a blend of brown rice flour, vermiculite, and water. The jars are then sterilized in a pressure cooker, inoculated with spore solution (or liquid culture) and left to colonize.
When they’re fully colonized, the “cakes” of mycelium are removed from the jars and placed in some kind of humidity enclosure - a common example is a shoebox with a layer of hydrated perlite.
The cakes eventually pin up, and pop off some ‘shrooms.
It sounds simple enough, and this system has long been advocated as a short-cut around germinating spores on agar, inoculating grain, then inoculating a bulk substrate.
The benefits, according to its proponents, are a faster time to harvest and, allegedly, a lower cost of entry.
The tradeoff is that cakes drastically under-produce compared to bulk substrate. Also, spores are never a completely clean sample. That means shooting them directly into any growth substrate is prone to higher contamination rates compared to germinating them on agar and making clean transfers.
In this series, I want to examine whether those benefits are really significant enough to recommend new cultivators start their journey with PF Tek, or if they’d be better off learning the fundamentals of agar, grain transfers, bulk substrate, and monotubs.
Disclosure: I freely admit that I am biased towards the agar>grain>monotub method. I’m going to do my best to stay impartial and open-minded, and represent my findings as honestly as I can.
This first exploration is easy, because I want to examine whether PF Tek is actually cheaper to set up than the monotub path.
To do this, I chose an online retailer that offers as many of the necessary supplies as possible for both methods. In this case, that retailer was Walmart.com. I also assumed that the cultivator in our experiment had no supplies or equipment on hand already.
I ended up going to a brick-and-mortar retailer for just one item: agar powder. This is because the online prices were genuinely outrageous compared to the Asian supermarket, and I don’t believe this ingredient would be hard to find for anyone living in a decent sized town.
The results:
As you can see, PF Tek did come in cheaper, by just a hair under $16. Obviously this number might vary depending what equipment and supplies you’ve already got on hand, and the prices you can find by shopping around to other retailers.
So there it is. Technically, if you do your shopping on Walmart.com, PF Tek is the slightly cheaper approach.
Is that $16 savings worth it?
To find out, I collected feedback from community cultivators about the typical harvests they collect with each method.
Answers obviously varied widely, but we landed on an average of about 80g of dried mushrooms from a monotub, and 5g per cake using the PF Tek. (In this chart, I assumed 4 cakes colonized successfully and made it to fruiting.)
By breaking the input cost down into the yields, we landed on some very different numbers:
A monotub setup produces its first harvest at approx. $2.15 per gram of dried mushrooms.
4 PF Tek cakes (assuming no monetary loss to contamination - that’s a subject for another writeup) math out to $9.18 per gram.
Of course, this isn’t exactly a revelation, as we already knew monotubs were the more efficient method in terms of yield.
Also, differences may arise on subsequent cultivation cycles, because much equipment only needs to be purchased once (pressure cooker, jars) and many ingredients are sold in quantities that support more than one cycle (rice flour, oats, agar) and don’t need to be re-purchased every time. That’s a bit of nuance that I’ll explore on an ongoing basis over many cycles.
Next time, I want to address the notion that PF Tek is the fastest method, because it cuts out agar prep and colonization time for bulk substrate, jumping right to fruiting.
My guess: PF Tek will be faster, but not by as much as many people think.