David,

I think of Golden Buffalo flour (Heartland Mill, available by mail order - they have a web site) as a sifted stone ground whole wheat flour made from high protein wheat. It is produced by taking their organic stone ground whole wheat flour and sifting it to remove a fairly large portion of the bran, which creates a flour that is high in ash content (around 1.15% - I ran tests on it at CII Labs in a blog entry) but low in bran, i.e. it still has much of the original germ and outer portions of the endosperm and inner seed coat but with relatively small proportions of the original bran. It is my favorite flour for use in situations where a "high extraction" flour is called for.

Although a passable substitute for high extraction flour is some mixture of whole wheat and white flour, it still is quite different from a true high extraction flour. In fact, a much closer approximation is to mix white flour with wheat germ and first clear flour and maybe some amount of bran, depending on what "extraction percentage" you want to simulate. As a rough approximation, you could say that a 50/50 mix of white and whole wheat flour has about the same ash content as Golden Buffalo, but the 50/50 blend would have half of the outer endosperm (approximated by first clear flour), and half of the germ but a much larger proportion of bran compared to Golden Buffalo flour.

Golden Buffalo flour is about halfway between white flour and whole wheat flour in ash content, with much of the bran removed, but not all. To produce substitutes for high extraction flours that have a lower ash content than Golden Buffalo, you can then reduce the ash content further by mixing white flour to get a lower extraction subsitute that is closer to in composition to any given high extraction flour with a lower extraction percentage. Also, you can add a little bran to raise the ash content if you want.

Lately, I've been playing with making my own high extraction flours by milling and then sifting them myself, using a gradual reduction milling and sifting process, which is the theme of a few recent blog entries. I'm not saying it's recommended reading, as it's an eccentric, mostly impractical personal diversion, but if you are interested in stone-ground and sifted high extraction flours, then you may find some good information embedded here and there in those entries. At the very least, the lab results include some analyses that were done on various Heartland Mill, Wheat Montana, and KA flours along the way.

Bill