Mash Grain Bag BIAB 70x85cm - 63 Micron Polyester Brew in a Bag

The bag that turns any kettle into a mash tun: 70×85 cm of 63-micron polyester mesh with a reinforced 25 mm webbing rim. Line the kettle, mash in, lift the bag — and you've done all-grain brewing without a mash tun, a lauter tun or a sparge arm.

63 micron is the sweet spot: fine enough to hold back flour-fine crushed malt, open enough to drain fast and rinse clean. The webbing rim takes the full weight of 8+ kg of wet grain without tearing, hangs over the kettle lip, and the flat seams don't trap dough balls. Machine-rinse, air-dry, reuse for years.

Key features

• 70×85 cm — fits kettles up to ~50 L
• 63 micron polyester mesh: clear wort, fast drain
• 25 mm webbing rim carries 8+ kg of wet grain
• Flat seams — no stuck dough balls
• Reusable for years; rinses clean in minutes

Usage

• Line the kettle before mashing in; clip the rim over the edge
• Lift slowly, let it drain, then squeeze — polyester laughs at mash temperatures
• Crush finer than three-vessel brewers do: the bag IS your filter, efficiency jumps

Quick facts

• Size: 70 × 85 cm
• Mesh: 63 micron polyester
• Rim: 25 mm webbing
• SKU: KL01304

Related products

• Nylon Hop & Grain Bag 4L
• Nylon Hop & Grain Bag 15x20cm
• Stainless Hop Spider
• MaltZilla Grain Mill with Motor

From the blog

• Your First All-Grain Brew Day: A Complete Beginner's Guide