Quick question Y'all. I've been running bucket tek to pasteurize my Coir/Verm/Gypsum substrate, but I've ended up with some contamination on a couple tubs at this point. (I'm sure it's the substrate doing it, not grains or ambient)

Would it be worth it to pasteurize on the stove in a bag instead? Better consistent sterile results? Or is it about the same efficacy as bucket pasteurization with boiling water?

When you say on the stove, do you mean with a pressure cooker? If I'm not mistaken a pressure cooker will get a little hotter than regular boiling water and the pressurizing component should help aid in sterility.

One love

I can’t remember if this is true or not, but I believe you don’t want to full on sterilize(pressure cook) your sub. Pasturizing and sterilization are different. A cool pasturizer trick I found online is to remove the weight from the pressure cooker, run a hose to a sterilite heavy duty tub from the discharge of the cooker. You first get your sub to field capacity, then put it in a heavy duty garbage bag. Run a large cooking thermometer through the lid and into the center of the bag of sub, so you’re making sure it’s pasturized all the way.

But in all honesty, unless I’m doing large batch of substrate, I usually just stick to the boiled water in a bucket way. Ease to success ratio is worth it to me.

Ignore my response. I wasn't thinking, because I definitely responded as though it for sterilization. My apologies.

One love

I think boiling water is not as good.

The standard is to keep the bulk substrate at ~140F to 175F window for am extended time (2 hours). Mixing in boiling water kind of does that, but oven is better: Gentler heat up, even temp. With boiling water you'll have spots that could get to joy and other spots that may be to cold depending how the water mixes. Also, you may drop below 140F before the two hours are up, or you may be above 175C for some time. I guess it can still work, but oven control would be more proper in my opinion.

hello Th3k1d93,

In my experience 99% of the contamination comes from dirty spawn. Can I ask how are you sure that the substrate is causing it? I would focus more on how you prepare the grains.

Sometimes when I'm lazy I don't even pasteurize my sub. I just put some warm water instead of boiling then mix and spawn immediately. I've done it 6-7 times and haven't had a contamination once (although I would recommend sticking to Damion5050's Bucket TEK).

One more thing to consider is the type of cocount coir that you're using. The best kind is the one for reptiles. The ones intended for plants may have trichoderma added to them.

Have also read/heard this about coir intended for horticulture. I usually keep to a specific compressed bedding type and bucket tek works fine for me. I can proly run it with cold water if I felt like, but I like the texture after heating/cooling.

Anything aside from coir and I'd rather pasteurize in jars on the stove. My needs don't warrant anything more than the few jars I can run at once.

Except for gourmet cultures. Expanding the amount of straw I can accommodate is on a future to do list.....

TBH, your contam is most likely coming from somewhere else or improper technique in cleanliness. CVG Does not need to be sterilized and pasteurization happens naturally by pouring correct amount of boiling hot water onto the dry ingredients(to bring to field capacity) in a 5 gal bucket and close up , shake(careful there will be some pressure there). Unlatch the lid one notch and wrap with a blanket and let sit for 6 hours. Ready for use.

You want to be sterilization your spawn though.

Check all your bases. You'd really need to detail more information about what youre doing and what stage youre seeing contam.. Good luck!

Everything you are "pasteurizing" is inert and contains no nutritional value whatsoever so the problem is dirty spawn. 100%. I have put clean spawn in tubs that has trichoderma in them in the past just to prove this on another website. While there are parasitic strains that can pass from one to another they are rare and as previously stated dirty spawn us almost always the cause of the green.