Half White Bread Flour vs Regular Whole Wheat and AP
Is it ok to sub half white bread flour for the two flours listed? It is the only flour available in NYC while we are on pause. Tartine 3 uses a mix of high extraction (whole wheat passed through sifter to remove the bran) plus all purpose. Bread flour is used for the starter but not the bread.
Recipe question for: Oat Porridge Bread
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Background: I've made this bread twice before (using regular AP and regular Whole Wheat flour, but using bread flour for the starter/leaven as instructed) following his high extraction method with the whole wheat regular (not bread) flour, running the flour through the sieve to remove the bran as described in his book.
Had great results both times, so I'm hoping that using the readily available Farmer Ground Half White Bread Flour will work out.
In Tartine 3, Chad says that when he calls for "medium-strong wheat flour," he means " 'bread flour,' or a blend of all-purpose and bread flours...that has 11 to 12 percent gluten with good baking qualities to add strength to the dough while avoiding the toughness." Bread flour, in this case, would work well in place of the 500 grams medium-strong wheat flour the recipe calls for. Most commercially available bread flour has between 12 to 14 percent gluten content, just a hair above the range Chad suggests. I think it would be a fine substitute here.
The other piece is the high-extraction wheat flour. If you don't have this available (or enough of it), Chad says to use a 50/50 mixture of 100 percent whole-grain flour with white flour (in this case, probably bread flour in your situation) as a substitution.
Last thing to note—bread (or any higher-gluten) flour absorbs more water than lower-gluten flours, so you might need to pay a bit more attention to the hydration of the dough and adjust water accordingly. From what I've been reading in the comments, the dough is on the moister side, so something to keep in mind!