Thought some of you may like to know this: I think this is sold between mid-December and early February, site has codes and best by dates
Go to this site for more info. I grabbed this small amount of text
The King Arthur Flour Company has initiated a voluntary recall of a limited number of our 5-pound bags of all-purpose and bread flour. King Arthur Flour places great emphasis on providing customers with the highest quality products and services, therefore out of an abundance of caution we are issuing this recall.
Small, polyurethane balls approximately 7mm to 9mm (1/4” to 3/8”) in size may have dropped into bags during the final sifting stage of the milling process. The balls have a smooth surface and no sharp edges and are made from food grade material. Because of their bright blue color and size (about half the diameter of a dime), they are easily seen in the flour.
Any affected products may be returned for a full refund. For more information call the King Arthur Flour Consumer Hotline at 866 797 9178, open Monday-Friday, 9am-6pm EST.