To make bags fastened with grommets, rather than sewn together, one needs a grommet machine, We have some! BagShare has some. They can be borrowed with everything you need to run your own bag-making workshop. Friends of Reusable Bags can help. After a bit of practice, a bag can be made in about 10 minutes. We will post step-by-step instructions here in the future, too.
Malt bags are large, sturdy, usually double thickness, waterproof, and have a carrying capacity of about 50 pounds.