Turning Meals Into Memories Since 1851™. In the mid 1800's, Carl Hilmar Guenther toured America in search of opportunity and the perfect place to begin his first milling enterprise. More than a century and a half later, we're pleased to announce that he was successful in finding both. C.H. Guenther & Son, Inc., and the Pioneer Brand are the oldest continuously operated family-owned milling company in the United States. For over 160 years, we have proudly made products with superior taste and performance. C. H. Guenther.