Reusable grain jar lids built for repeat sterilization. PP5 body rated to 330°F, 20mm PTFE filter sticker, self-healing silicone injection port, and a silicone o-ring seal. Fits standard wide-mouth mason jars.

Perfect For

• Making grain spawn for bulk cultivation

• Sterilizing grain in wide-mouth mason jars

• Master spawn jars for long-term use

• Anyone running enough jars that disposable lids stop making sense

Why Growers Choose These

• Silicone o-ring seal. Seals against the jar rim rather than relying on metal-on-glass contact, which means a consistent seal through sterilization and storage.

• PP5 construction. Food-safe polypropylene rated to 330°F. It won't warp or deform through repeat autoclave cycles, and the lid body will outlast everything else on it.

• 20mm PTFE filter sticker, 0.3 micron. Hydrophobic, so it sheds moisture instead of wetting out. The same filter I sell by the sheet.

• Self-healing silicone injection port. Closes behind the needle after each inoculation. For average use it'll go several months before the accumulated sticks catch up with it.

• Serviceable, not disposable. The filter and port are the wear items. The lid itself keeps going.

• Fully autoclavable. Lid, filter, port, and o-ring are all rated for pressure sterilization.

• Fits standard wide-mouth mason jars. Ball, Kerr, and equivalents. Jars sold separately.

The Myco Powered Difference

This is a relaunch. The lids I sold before used a filter I wasn't satisfied with, so I went looking for something better and rebuilt the product around what I found. These now use the same 20mm PTFE filter stickers I sell by the sheet — hydrophobic, 0.3 micron, and they hold up to repeat sterilization instead of wetting out and failing.

Most grain jar lids are disposable by design. When the port tears or the filter gives out, the lid goes in the trash. These don't work that way. The PP5 body and o-ring will outlast your interest in the hobby, and the filter is a part you can replace from stock. Replacement injection ports are the one piece I don't carry yet — I'm working on a supplier — but the port will go several months of average use before it needs attention.

Four to a pack, down from six. Six was more than most people need and a bigger up-front spend than it was worth. Four covers a typical run.

Wide-mouth mason jars sold separately.