"Does anyone know when you would choose "hard white" vs "soft white" vs "hard red" wheat?"

From Small-Scale Grain Raising by Gene Logsdon:

"There are five commercially important wheats grown in the U.S.: hard red winter, hard red spring, soft red winter, white, and durum. The hard red wheats are grown mostly west of the Mississippi and are used commercially for making bread; soft red winter wheat is mostly east of the Mississippi and is used principally for pastries (but is fine for bread). White wheat you’ll find chiefly in the Pacific Northwest (and NY and New England) and is used for bread. Durum, grown almost exclusively in North Dakota and surrounding states, makes the flour for pastas."

Sue