Buy thick firm, healthy ones. Wash in plenty of water Drain water in a large colander Then dry in strong sun. See that they are absolutely dry and brittle, before you pound. If grinding in a machine, then pound to a semicrushed state by hand, to avoid the blades of the dry grinder from injuring. Dry turmeric in strong sun for an hour See that they are absolutely dry and brittle, before you pound Pound If grinding in a machine, then pound to a semicrushed state by hand, to avoid the blades of the dry grinder from injuring.