Notes.mdLast modified 5 days ago

How it started

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After a bought a ready to grow kit from shrooms.sg. I wanted to do this again but without paying for the kit, so I started to study & figuring out how to grow mushrooms.

Processes

Life-Cycle

Mycelium is the vegetative part of a fungus or fungus-like bacterial colony, consisting of a mass of branching, thread-like hyphae. You will see this word very often when touching the subject of mushroom cultivation. What we eat, is the fruit body that releases spores (like seeds but not seeds), typically under the cap, & the cycle repeats…

Cultivation

The whole point of the sterile methods at the top of the diagram, is to grow a sizable amount of mycelium to transfer to different types of food (the substrates) for mushrooms. So from agar (highest nutrient), it goes to spawn (usually lower than agar). From colonized spawn, mycelium is then broken up & spread into bulk substrate which is even lower nutrient-content but cheap or even collected waste eg. spent coffee grounds.

Cloning

When mushrooms are grown from spores, there are chances of mutation. Instead of depending on chance, farmers/cultivators develop/reuse techniques to clone from desirable specimen of mushroom (eg. grows very quickly, has nice big caps & so on…). They will cut a tissue sample, put into a petri-dish with agar, let it grow to a point that they can observe the strains under magnification to cut parts of the agar to grow a few more runs as a means of isolating the desirable strain.

Liquid Culture

A sterile environment is for the transfer of mycelium to agar or to substrate (food for mycelium).

LC is a popular amongst hobbyists to clone since it requires less sterile environment. Sealed jars with modified lids reduce risks of contamination. These lids have air-exchange & injection ports.

The fun for me started when I saw the King Oyster tissue growing in the sterilised (or I thought it was) honey broth:

My initial attempts were primitive. No proper injection ports & air-exchange. I basically punched a hole through the cap & stick 3M micropore tape of the hole. The problems are detailed at the later section.

You can find better ways with Youtube using these keywords: Liquid culture injection port. After the mycelium clear out the nutrients in the Liquid Culture of honey, the water will look clear. And since I did not break up the mycelium, which looks like a continous network of brown cotton. Professionals go beyond like eye-balling the water. They will inject samples of LC into agar plate for testing, by letting mycelium (or contaminant) grow.

At this point, the LC needs to be transfer to a solid substrate, the question is what. Instead of the usual spawn to bulk-substrate process, I wondered how to short-cut this & I found PF Tek.

PF Tek

PF TEK is basically a brown rice method with an improved formula by using vermiculite as a base and adding pulverized brown rice. The secret is in the vermiculite. When mycelium is cultured in just grain, the mycelium turns into a mass with little air space. But when grown with vermiculite, the mycelial threads stretch across space.

The important thing about the PF TEK, is that it copies nature. Instead of the usual cloning of mushroom tissue and growing mushrooms from that, a mass spore inoculation is employed directly to the fruiting substrate. That way, the genotype remains complete. Senescence (mutating and ceased fruiting) is no longer a problem. The spores insure a never ending succession of fungus, with all the power of the spores reproductive ability intact.

So basically it is brown rice flour mixed with vermiculite & water in a certain ratio, pressure cooked to be sterilized. Instead of spore, it is common to use LC. Why is it so popular? Getting the Field Capacity (of water) for different grains is HARD, it is hard to get it wrong with easy to remember 2:1:1 ratio for vermiculite, water & flour. I replaced brown-rice with wheat flour, it works equally well. So what can go wrong?

Problems

Choosing the wrong species to start…

I have this thing for King Oysters. Unfortunately, I did not take into account of temperature. Singapore is too hot for King Oysters.

Solution

Bought Liquid Culture syringe from US & ship it into Singapore. I was surprised that the syringes managed to get to through. This time round, I bought Pink & Yellow Oysters syringes, which are ‘warmer’ species.

Sterilisation

Singapore is a warm & humid country. Placing wet food into containers without proper sterilisation is a receipe for failure. A kitchen steamer will not nuke all living things with a single round no matter how long we steam it. Some spores may survive 121 deg-C, so shroom (aka magic mushroom) hobbyists tend to cook their jars for >1 hr. Autoclave, the fancy name for pressure cooker meant for lab sterilisation, can be a hazard at home with young kids.

Solution

Bought a cheap but good home pressure cooker that is easy to use. Instead of long cooking, I use what is known as Tyndalisation aka Fractional sterilisation. Basically shorter cooking it (40 mins) multiple rounds (at least 3 times), with ~24 hr breaks in between cooking. During the breaks, spores turn into bacteria, thus vulnerable to heat lower than 121 deg-C.