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Sterilization Tips

A few tips on how you can avoid contamination by increasing your sterilization procedures by Ryche Hawk.

Hello fellow mushroom enthusiast. I wrote the document to help with aiding in sterilization when growing mushrooms. You may already consider yourself very sterile when preparing your substrates, but hey there may be something here you haven’t thought of. And for those of you having problems with contaminants this may be very helpful.

Lets see where to start. Before starting the cleaning process, I like to turn the air conditioning about 10F cooler for 2 hours ahead of time, to cool the house down, then turn it off when I begin and leave it off. This keeps new airborne contams from entering, same goes with the heater. Then I take a shower, and put on freshly laundered clothes, remember we carry more bacteria then anything else in the house. Also I put my cat in a the bedroom with her food/water and cat box and leave her in their till I’m done. Next I start with the kitchen. Before you start the cleaning process.. get anything out of the fridge you want now.. water.. food etc... I don't ever open my fridge until I'm completely done so know unwanted germs fly out. Start off by scrubbing down all the counters thoroughly, especially the sink and counters you'll be working on. I like to use Simple Green, an organic and highly effective cleaner. Then I sweep and mop the floor with Simple Green.

After this I bring my HEPA air filter in the center of the kitchen, I highly recommend one of these, there only $45. I then have one can of Lysol in the kitchen and one outside the kitchen. I liberally spray everything from the windows, cabinets, ceiling, floor, carpet outside the kitchen liberally. I spray the counters and sink with pure isopropyl alcohol, its a good idea to keep a spray bottle full of this around also. I also where a dust mask so I don’t have to breath this stuff. Next give about 10 minutes for the Lysol to settle down in the kitchen. After it has settled down, if you own a flowhood, now is a good time to bring it in the kitchen to start filtering out the air.

Most importantly that has changed to this document is the use of isopropyl alcohol, found at any pharmacy or grocer store these days. Try and find the 99% stuff if possible.. but most places only carry 91-97%.. this will work fine to. I use a lot of alcohol these days for sterilizing most things. Especially tools or things brought to the work area such as exacto knives, tape, the bottle of alcohol, plates, pens, tinfoil, lighters, .. whatever, and wipe it down with a lightly saturated cloth. I prefer to use KimWipes. Their lint free and work great. I keep boxes of these on hand.

As for cleaning jars.. if your reusing jars.. then after you initially get all the old substrate out, I do this with a high pressure hose outdoors, I then soak them in a big tub of 10% bleach to water for 6 hours. Much longer, like a day or more.. and they start to build up a bleach residue that is hard to wash out. Anytime your reusing jars..especially ones with contaminated substrate in them previously.. its very important to soak them in bleach, not all contams are killed by warm water and soap. I then take all my jars and lids to the sink where I scrub them out with Simple Green and a sponge, and rinse them real real good to get all the cleaners out. Have some shishka-bob sticks lying on the counter, set the jars lid side down on the sticks to dry out. At this point I bring all my bowls and utensils in to wash them as well. Everything is washed with Simple Green, I mean everything. Anything that comes into the kitchen gets sprayed with Lysol then taken to the sink and washed. This includes bags of perlite, vermiculite, rice, birdseed bag, the distilled water gallon jugs, any utensils used, paper and pen for notes, you name it, if its in the sterile zone it gets sterilized with lysol or alcohol. One thing that is really important.. is to spray yourself down real good anytime you take a break and come back to the work zone. Also remember to wear that dusk mask so your not breathing germs all over the work area. I no longer use rubber gloves since I discovered Germ X. Its a waterless hand sanitizer that kills 99.9% of the germs. You put it on your hands dry, and it evaporates very quickly without leaving a film on your hands like other waterless sanitizers such as the lysol brand. I use this stuff constantly on my hands and arms while working. Your fingers will release oils constantly, which you don't want on your prints or tools while working with spores. I also sterilize my vermiculite, peat moss, and perlite in the microwave for 5 minutes before using.

While preparing the jars, if they still haven't dried, wipe the inside down with a paper towel or KimWipe. After filling jars 3/4 full with substrate, if using the dry vermiculite layer, wipe down that upper area of the jar with a damp alcohol soaked Kimwipe to remove any excess substrate lingering up there where the dry vermiculite layer will go. Then after preparing the jars pressure cook them at 15 psi for 45 minutes or steam them at a low steam for 60 minutes if no pressure cooker available. If you don't own a pressure cooker, I highly recommend investing in one. Steaming your substrate is only good for substrates like ground brown rice, or bran flakes or ground flax seed, but any time you use grains such as birdseeds or rye grain, you definitely need a pressure canner. Reason being is a lot of eggs and other bacteria store inside the grains, and steaming them wont kill them completely. The pressure canner not only kills them with heat, but with pressure to get inside the grains. I've seen some small 8 quart pressure cookers/canners for as low as $35 that hold 8 1/2 pint jars at a time. The 17 Quart units hold around 21 jars and the 22 quart models hold around 28 jars. Another good practice is steaming your syringes for 25 minutes in a pot of low boiling water with the lid on. This is only for reusing syringes, not for syringes with spores in them of course. Then I keep one of those minny torch lighters around for sterilizing the needle, or you can use an alcohol wick lamp, these things work great as well. Lately though.. I just wipe the needle down with a damp alcohol kimWipe, especially in between inoculating jars. Also in The Mushroom Cultivator, it suggest for people having a lot of problems with contamination, is to use a wick lamp with triethylene glycol that is vaporized through the heated wick. This can be ordered at chemical or lab supply houses. Quote from TMC " By asperating sterile oil, a cloud of highly viscous droplets is created. As the droplets descend they trap airborne contaminant particles. Finer and more volatile then mineral oil, triethylene glycol leaves little or no noticeable film layer." I personally don't have many problems with contaminated jars since I started using a pressure canner. These days.. after I inoculate the jars.. I keep the tape off, and put about 6-8 jars in a filter patch bag obtained from Fungi Perfecti. I then seal the bag with this little heat sealer called a EuroSealer, found at Target and Walmart for $15-$20. It seals the bag so the only air exchange is through the filter built into the bag. This will help with gas exchange while the jars are colonizing, as well as help keeping contams out of the jars. If during the colonization process, you notice some jars that are contaminated, immediately open the bag up and pull those jars out. Use a fresh new bag, wipe all the jars down with alcohol, and reseal them. You can re-sterilize these bags and use them again. They are great.. and about 10 for $8 through Fungi Perfecti and I believe The Cultivation Station has them as well now.
Also when using tools for cutting caps off mushrooms and such or scissors for cutting into prints, I like to wipe them down with alcohol then use the torch lighter to double sterilize them, then wrap in alcohol sterilized tin foil till ready to use. Let them cool before using.

Also very very important. When it comes time you need to open your aquarium lid and touch or play with your mushrooms, be sure you are very clean when you do so. I try and make it a rule to only do this fresh out of the shower, but we cant alway be that clean. So I keep a dusk mask and a bottle of Germ X and lysol by the growing area to clean myself real good before opening the grow chamber and reaching in. Believe it or not.. if your getting problems with green mold, trichoderma, on your casing layer or cakes, its probably because you introduced the contaminant to the area, we do carry a lot of germs on us, even though we are a supreme species of this universe ;).

Well that’s about it, just remember to sterilize everything that comes into the kitchen, even the Lysol can itself, remember its been sitting on a shelf in a store somewhere with dirty hands being placed on it. I hope this helps, if anyone has anything to add to this send it to me.

Myco Supply
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