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.