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

I've been using these bags for 6 months for grain spawn (both rye and oats) and they work great! I will be ordering them again. They do not need to be wrapped with towels and will not melt in a pressure cooker, even when touching metal sides (IF you make sure there is enough water in the pressure cooker). This is best achieved by getting a trivet or riser to allow at least 2-3" of water in your pressure cooker. This is especially crucial if sterilizing for 2+ hours at 15 psi. Ruptured bags in pressure cooker has only happened to me when I pre-seal the bags before pressure cooking, Melting has only occurred when my pressure cooker runs out of water (riser has been a game changer). Make sure you put something on top of the grain bags to prevent blocking pressure cooker venting and exploding (use original bottom rack for this if you get a riser). NEW TRICK: use a small paper hole punch to create bag vent and pre-seal bags before pressure cooking (punch hole below where you want to seal; can fold bag edge a bit to get hole punch 1-2" below sealing edge). Then it is super easy to add a small sticker based filter patch to the whole you punched once bags cool...then use resealable injection port stickers to inoculate w/ liquid culture (once grain bags cooled). I use a standard food sealer instead of an impulse sealer. This requires letting it cool for 60-120 seconds before opening lid of food sealer to cool the seal enough to not weaken the seam when you peel it off the heat strip. Peel vertically to keep seal best intact. I have used whole rye grain for 15 years and I recently switched to whole oats from Tractor Supply. At $20/ 50 lbs, not only are whole oats way cheaper, they do not burst and dissolve as easy as rye and can withstand 2 hours+ at 15 psi in the pressure cooker. Using no soak, no simmer method with oats is awesome! Weigh your oats, and use 75% of that volume for your water measurement (3 lbs of oats needs 2.25 lbs of water). Also, water can be weighed and has the same weight # as Liters or ml.... So make your life easier! These bags in my opinion, max out with 4lbs of grain (dry) to allow for some mixing ability in the bag. You can do less work!

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.

Bags are good. Autoclave perfect. Filter is perfect. Just a bit to short to fill my needs. I would buy a ton of these if they were 19 or 20 inches tall.

The bags are easy to clean, kill bacteria and mold. Bags can fill with spawn and substrate. They can hold a good amount of spawn and substrate. I would buy again.

They work as described thank you! will buy again when needed.

Fast shipping. Item as described.

Unfortunately, this product is not compatible with 15 PSI pressure cookers. During sterilization, the bags melted and adhered to the side and bottom of the pressure cooker, leaving a difficult mess to clean and not to mention wasting all the grains. I’ve used similar products before without any issue, so this experience suggests that the material quality may not meet higher temperature standards. If your pressure cooker operates at 15 PSI, I would recommend looking for a more heat-resistant alternative.