One reusable cloth bag big enough to stretch over the opening of a fermenter...see the photo as an example

Made from stretchy mesh cloth these bags will expand to hold large quantities of grain or tie them up for small quantities of hops.

Tip  - place a bag over the mouth of your open fermenter and secure it tight using your lid o-ring. Next pour the contents of your boiled pot ie grain or hops into the fermenter and strain thoroughly through the bag. Once you have finished empty the bag and rinse for reuse on your next brew.

Always sanitise the bags before use.