U.S. wheat production problems could worsen food inflation.

The spread between hard-red winter wheat and soft-red winter wheat has blown out to a record high as drought threatens crop yields across the Midwest and other major farming regions.

Hard-red winter wheat's premium over soft-red winter wheat is $1.72 a bushel in Chicago on Tuesday morning, surpassing the 2011 record.

James Bolesworth, managing director at...