Best filter patch grow bags for oyster, shiitake and lion's mane blocks

What the listing offers

• The clearest sterilization rating in this guide: autoclavable up to 250 F (121 C) at 15 PSI for 90 to 120 minutes.
• States a capacity of 4.4 to 5.5 lb (2 to 2.5 kg) of substrate per bag and names oyster, shiitake, lion's mane and king oyster.
• 0.08 mm polypropylene, which the seller describes as 30% thicker than standard 0.06 mm bags, with a self-standing gusseted base.

Limits to know

• The stated limit of 90 to 120 minutes at 15 PSI is shorter than the 2.5 hours many sawdust block recipes call for.
• Thickness is given in millimeters only, so comparing with bags rated in mil takes a conversion.

What the listing offers

• 6 mil polypropylene per the title, with side gussets and a tear-resistant design.
• Listing says the bags are designed for high temperatures and pressures up to 15 PSI.
• Fifty bags, each with a 0.2 micron filter patch, and oyster mushrooms are named among the intended uses.

Limits to know

• No substrate capacity in pounds is stated for the bag.
• No sterilization time limit is given, only the 15 PSI pressure figure.

What the listing offers

• Extra large 10 x 5.5 x 24 inch (25 x 14 x 60 cm) bag, stated as 40% more room than standard bags.
• Thickness is given in both units, 0.08 mm and 3.15 mil, in polypropylene.
• Listing says the bags endure 260 F (126 C) high-pressure steam and are designed for wood-decay fungi such as lion's mane, shiitake and oyster.

Limits to know

• No substrate capacity in pounds is stated, so block weight has to be worked out by the grower.
• A 24 inch tall bag filled to capacity takes more room in a pressure cooker than a standard block.

What the listing offers

• Listing names oyster, shiitake and reishi among the species the bags are meant for.
• 8 x 5 x 20 inch bag, described as the standard size, with a 0.2 micron filter patch on each bag.
• Made of polypropylene, with thickness presented as the reason for fewer breaks in the autoclave.

Limits to know

• Thickness is listed as 0.8 mm, while the same brand's 100-unit listing says 0.08 mm: treat the figure as unconfirmed.
• No temperature, pressure or time limit for sterilization, and no capacity in pounds.

What the listing offers

• Small pack of 10, enough for a first few batches without buying in bulk.
• States a capacity of 4.5 to 5.5 lb per bag and a size of 20 x 12 x 50 cm (8 x 5 x 19 in).
• 3 mil polypropylene described as heat resistant to 121 to 125 degrees Celsius, with autoclavable in the title.

Limits to know

• The filter is 0.5 micron, coarser than the 0.2 micron patches on most bags in this guide.
• Only 10 bags per pack, so a grower making blocks regularly will reorder often.

What the listing offers

• Listing identifies the bag by Unicorn's type code, 3T, so the same bag can be found again when reordering.
• Reads like a spec sheet: material, bag size, filter size and rating, and typical block size are each stated.
• Typical block size is given as 5 to 7 lb, and the pack holds 100 bags.

Limits to know

• At 2.2 mil this is the thinnest plastic with a stated mil rating in this guide.
• The listing does not use the word autoclavable or give a temperature limit, and says the bags arrive without the Unicorn logo shown in the photos.

What the listing offers

• Narrow 5 x 4 inch footprint at 20 inches tall, the smallest bag in this guide.
• 6 mil thickness with side gussets, described as built for pressures up to 15 PSI.
• Fifty bags per pack, each with a 0.2 micron filter patch.

Limits to know

• No capacity in pounds is stated, and a 5 x 4 inch bag holds a smaller block than the common 8 x 5 inch size.
• The listing details available do not name the plastic and give no sterilization time limit.