Bulk substrate bacterial contamination

I’ve recently started cultivating mushrooms. My first mono tub went smoothly. The bulk substrate came from Midwest Grow Kits. I got one order of the standard coco coir based bulk sub and one of their cow manure based sub. Both should be sterile and ready for spawn straight from the bag

The first one I added spawn to was the the coco version and it went all the way to harvest with no hiccups and produced 2oz of great fruits.

A couple days after spawning to the coco, I used my second healthy spawn bag to spawn to the manure based sub. this one fully colonized then suddenly showed a green mold. I put it outside and the mold eventually took over the entire tub.

I decided to try the manure again and this time the same green showed up even earlier. I noticed the once healthy mycelium has also turned brown and mushy and smells bad. I took it outside and with gloves went through and there are barely any bits of healthy mycelium left. It’s almost all completely turned brown and mushy.

Should I be handling a manure based substrate differently than a coco based sub?

another question... I’ve got plenty of healthy spawn jars and three fully colonized rye grain spawn bags... the bag of bulk sub that got contaminated was my last. Is it possible to put the contaminated bulk sub in a pressure cooker and use new healthy spawn to attempt to colonize again?

Sounds like a heat issue. You may have burned the mycelium though I'm not sure how.

I've had bad luck with monotub fill kits myself. The first time I used pre-sterilized pasteurized horse poo from outgrow it went off without a hitch. So I got lazy and tried this again the following season but the sub got contams and turned green/blue. The grain spawn was clean and I knew it was but the sub must not have been. Even ordered up another 2-bags of h/poo which also failed similarly. Money down the drain.
Decided to go with a brick of coir with a little gypsum added and pasteurize it in a cooler with boiled water. Zero contams; tub produced just as many boomers as the h/poo sub at much less cost. Coir is my go to sub these days.
If you have clean spawn on hand I would just transfer it to grains and then spawn a tub of coir with it once fully colonized. Don't try to salvage anything else.