As your nukadoko pickle bed is used to make tsukemono, you will need to refresh it periodically with new rice bran. 
 
This is a 2 lb bag.
 
Rice bran can be used to make breads, cookies, crackers, baked goods and of course, nukadoko
 
It will keep in the freezer for up to 6 months.

Ingredients: 100% organic rice bran.