What is an extraction rate? And how does that impact the “whiteness” of a flour? That’s what reader Leslie is curious about today. Leslie, it’s a good question. Indeed I’ve received quite a few technical questions about flour since Friday’s post on white bread. My thinking is that I’ll answer that questions but also put together a few posts on flour and make a “flour primer” out of them for the ingredients section, since I don’t really have one of those yet. So then…let’s go!