It's more that there are specific brands of low-protein flour intended for biscuit-making that are commonly available in the South and less available elsewhere.

It's more that there are specific brands of low-protein flour intended for biscuit-making that are commonly available in the South and less available elsewhere. And, just for clarification, it's important to remember that when Americans refer to 'the South' or 'Southern' culture, they're referring to the southeastern states, east of the Rockies, and sometimes even to a narrower subset of these states. (For instance, biscuits are not a staple in Texas or Oklahoma.) Regional naming is often contentious in the US -- just ask which states are part of the Midwest and you might start an argument: https://www.vox.com/2016/2/16/10889440/midwest-analysis https://www.vox.com/2016/2/16/10889440/midwest-analysis Thanks for the info on the Chorleywood process, by the way. I'd never heard of it.