Box of 12 – 1 Litre Kilner Jars

For grain spawn or liquid culture jars

Key Features

• 1L / 32 oz capacity – plenty of head‑space for shaking grain or swirling liquid culture.
• Two‑piece 70mm metal lid – easy to modify with air filters / injection ports (not included).
• Heat‑resistant glass – holds up against repeated pressure‑cooker sterilisation.

Super Basic, No-Thrills Spawn Jar (the way I did it)

This is the technique I grew up on, it wasn’t fancy but it worked (even without a SAB or a flowhood, and in a dusty room!)

1. Make a hole or two in the gasket lid with a small nail
2. Fill jar 2/3rds with hydrated grain spawn
3. Attach the gasket lid and screw it shut
4. Wrap over the top of the jar with lots of tinfoil
5. Sterilise in a pressure cooker for 90 mins, allow to cool
6. Prize open the the tinfoil (don’t remove it!) just enough for you to access a hole, then inject 2-3ml
7. Cover the tinfoil is hiding the lid-holes
8. Leave to incubate – there should be enough air exchange through the lid-holes even if it’s covered in foil

Other options: After making holes in the lid, cover them with micropore tape… Or make a single larger hole and stuff polyfil (pillow stuffing) quite tightly into the hole which will double as a way to inject through and for air exchange. Or you can get super fancy and use purpose-made 70mm synthetic filter disc (SFD’s) within your lids. You could even fit a rubber injection port by drilling a 10mm hole then squeezing in the thick ones we sell (no glue needed). There are so many different way to make spawn jar lids, but if you see someone tell you to use glue (like it’s the 2010’s), ignore for a simpler way.

More Info

Made from thick soda‑lime glass to handle repeated pressure‑cooker cycles. Inspect glass for chips or cracks before each cycle.