A illustrated guide for preparation of grain spawn using birdseed
Pictures are worth a thousand words, I hope someone gets something from this. It´s extremely easy, as long as attention is paid to a couple of things;
1. Some kind of filtration system; FP, etc. filter disks and plastic lids are a fantastic combination. Polyfill and other filters work as well if done right.
2. Attention to the cooling phase of PC´ing. I believe this is where a lot of birdseed failures occur, along with significant departures from proper water content. At the very least, wrap an alcohol, 10% bleach, or other liquid-soaked wrag around the air intake of the pressure cooker. Let it cool in as clean of a place as possible, even a small hepa running in a dirty bedroom will suffice.
This is the quickest, no-mess method I´ve found for preparing birdseed jars. Not much to clean up, not a lot of grain down the disposal.
The type of birdseed really makes no difference, as long as you try for the lower sunflower seed brands. They are usually a mix of millet [the lighter colored, smaller grains] and milo [I think that´s it, the larger brown, BB-sized grains]
First, about 3 liters of mixed wild birdseed is submerged under lukewarm tap water. It is stirred for half a minute or so.
A handstrainer is a very useful item for this work. It can be used to skim some of the surface floaters--which include almost all of the sunflower seeds. No need to remove them all, only when in large numbers do they seem to cause problems. Notice the murky brown water. This wash contains a high number of bacterial endospores, mold spores, and ammendments/dust that can make the spawn sticky, and seemingly more susceptible to contaminants.
While submerged, the grain slurry can be poured through the handstrainer.
Once filled, the faucet is run over the strainer, giving a second rinse. This is then deposited in a separate mixing bowl. This is repeated until all the grain is washed.
Water added to the original slurry makes pouring it into the strainer easy and mess-free:
Grain is added to the jars to between 1/3 and 1/2 jar volume. It isn´t too important how much, though too much above 1/2 full can make the jars too full and difficult to shake. Vary this depending on inoculation methods.
Important: When adding water to the rinsed grain, it should be ´knocked´ a few times as the water level rises. This causes any major air pockets to settle giving a more accurate indication of water height.
The grain and water amounts are never measured, which is partly laziness, partly never-needing-to after doing it this way. If too much water is added, you can tilt the jar slowly and drain a little. This process could be sped up with pre-fashioned measuring devices, however rinsed grain never really ´measures´ that well. It sticks and makes a mess.
As the following pic shows, there can be differences in grain amounts used as long as the relative height of water-to-grain is similar. The black lines were drawn to the water levels "post-knocking".
After adding water to the last jar, go back to the first one and give each a final knock, making sure the ´water line´ is where it should be before loading the PC. I recommend 15 PSI for one hour, start timing when the needle hits 15.
The other big issue is inoculation technique, many good ones exist and the ones that work will vary between individuals. Personally, I make a slurry from agar growth and use it as liquid inoculum. Grain-to-grain is easy and shows quicker take-off growth, but requires a slight bit more technique, as the jar lids tend to be open for a longer time. Whatever you do, plan every hand motion in advance of opening any jar, so that the transfers/inoculations can be done quickly and with as little air movement as possible. This will allow predictable success in most lysol/glovebox systems, less attention to detail needed if using a well set up flowhood.
Some jars, left to right: Maitake [with a few dowels mixed in], Hericium, Cordyceps, and Morchella angusticeps. The jar in front was a jar prepared as in the above pics, with somewhat more sunflower seeds. . .3-4 hits after cooling and the grain comes apart with ease.
Q:Do you think 1 hour+15 minutes would be sufficient
if i use a vegtable steamer?
A: Without a pressure cooker birdseed can´t really be recommended. There
are methods of sterilizing without one, the two that come to mind are tyndallization
and post-pasteurizing peroxide treatment [effectiveness unknown to me]. Pressure
cooker is pretty much part of the game, IMO.
Q: The thing I´m curious about is this water level, though.
From your markings on the jars, it looks like you are creating a very wet mix.
If you can see water up to that line, then I´d think this is so saturated that
the mycellium will take forever to colonize. How long did it take those jars
in the pics to colonize like that? Every other mycellium culturing tek out there
cautins agains using too much water in the substrate. Yours seems to contradict
this warning. Please give some more detail on the approximate water amounts
A: One thing that I might have overlooked is the percentage of millet vs. milo
of various birdseed mixes. The measurements used in the pics above gave perfectly
shakeable spawn with no sludge, but the birdseed used was the cheapest stuff
on the shelf, not the higher millet content [i.e. NICER] stuff like Hartz etc.
Since millet is a smaller grain than milo, the ´water level´ type
of measurement will likely have to be adjusted if you use the nicer mixes. Specifically,
if you have a 100% millet jar, the water level would have to be closer to 1/2
the height of the grain I would guess. A jar of millet-only is just more more
dense, and the ´height of water to grain´ is absolutely dependent
on the density of the grain used.
One other thing to keep in mind, as Josh pointed out, is that allowing the grain
to sit submerged for any length of time will cause it to absorb appreciable
amounts of water, once again making it necessary to adjust the water height.
I apologize for not catching this obvious oversight, the variety of grain percentages
in ´birdseed´. The good news is that the method above will still
work, just lower the water level. Make sure to knock the jars to ensure the
grain is settled before adding water. There could very well be some other factor
that lets me use that water level, but I´m sure I´d get colonizeable
grain if I added an entire inch less. I measured it out the other day for the
heck of it, and using the birdseed above with the same water levels came out
damn close to a 2:1 ratio of seed to water. This is of course, nearly dry seed--it
sits submerged for no more than 5 minutes while being strained.
It´s a real individual thing with all the different products out there;
If finding the sweet zone is still tough, go ahead and run a batch with measured
out rinsed grain, and measure out differing amounts of water to each one. Keep
a simple set of notations so you know which one hit it right on, giving easily-shaken,
non-burst spawn. Duplicate that one and you should be off and running for a
full load right away [the same day, even].
Q: Would it be better to just go to a health food store and buy organic
millet and just use that instead of birdseed?
A: The millet at healthfood stores is usually hulled millet, meaning w/o hull.
You do not want to use that kind. If my town has a bird store, I´m sure
most towns w/ a decent population do. Try to either get millet w/ hulls or a
birdseed mix w/ lots of millet in it.
Shake the jar as soon as your pressure equalises. This will
mix the dry top portion of seeds with the moist bottom portion and make your
This is likely (next to the amoount of water used) the most important
thing with all grain preparations.