40 Pack, Mushroom Grow and Spawn Bags - Extra Thick Polypropylene Material, Tear Resistant - Size 13" x “4 x “4 with 0.2 Micron Filter Breathable - Spawn Rye

I've used these bags for about 3 years, they work fine with an impulse sealer or even a hair straightener, if your sealer is burning these, chances are like me and didn't read the instructions, when using an impulse sealer you must apply pressure 10 seconds after the impulse seal light has gone off or you WILL burn through your bags everytime. If that isn't the case then your sealer needs calibration. I've learned that thicker is not necessarily better, thicker bags crack more often. I recommend no thicker than 6mil. These bags hold up too at least 3 hours at 15psi. Back to practice, if your having contam issues asses your practice, these bags are perfect, and can fit so much more than with jars. These work good even for no soak no simmer tek. Avid customer here lol I can always rely on these bags

Quality is great. Really helps with a rookie margin of error. The smaller size also allows me to try different things without blowing the bank on grain spawn supplies.

worked as expected noting special just a plastic mushroom bag

Good bags, get the job done

Wanted to try smaller bags, so I picked up this brand. I have no contam issues, but the moment I use these I have thrown out so much! I have wasted so much money- won’t be using this brand again. As the bigger bags I was using from another company I have had zero issues with. May be the filter patch, unsure but wasted loads of time and money.

Great for getting agar bags for grain to grain transfers!

Melted to our pressure cooker

Each time I use the pressure cooker at 15 psi I put in jars and these bags filled with grain. My jars always work out. No contamination and the mycelium is always able to be transferred to saw dust. I've wasted about 10 bags worth of grain now. Each bag aaallways gets the craziest contamination. I've tried immediately sealing the bags and inoculating the bag with a syringe and putting micropore tape over it. I've tried quickly putting the grain spawn in the bag and then sealing it. Either method just gets contam. When I take out the mycelium from the jars and put it in the sawdust I haven't had contamination. Perhaps this isn't really a 0.2 micron patch? It's been an awful waste of time and money with these bags. On another note they don't seal well with the impulse sealer. Even on the lowest setting it burns right through or seals intermittently along the bag so it's not a full seal. I wouldn't buy these again.