I've been baking French-style bread loaves (not baguettes) for years. The ingredients are flour, salt, water, yeast, and about one tbsp cornstarch per cup of flour. For the last year or so, the inside of the loaves has sometimes been gray rather than white, but with little or no change in the taste. I have not changed ingredients nor preparation technique. Flour has been King Arthur bread flour for years. I am at a loss to explain the change.
I'm in Atlanta, about 1,000 feet above sea level. Earlier this summer, I made bread every day for two weeks at a beach house party, using equipment and ingredients brought from home. Every loaf turned out perfect, with no hint of gray. I have no idea why that might make a difference. (There's an electric oven at the beach, gas at home, but I made perfect, or at least white, bread with the gas oven for many years before this problem started.)
Also, if I cut into a loaf right after it comes from the oven, it's always white. The graying process seems to happen over a couple of hours. (I bake in the afternoon for an evening dinner.)
Edited October 5 to add: Additional data points: I've bought a three-loaf baguette pan with perforated bottom and I've been using it for about a month. No gray bread. I've introduced three new variables:
- Three loaves of about 260 g unbaked weight instead of two at 390-400 g unbaked.
- The pan is non-stick aluminum instead of black steel.
- The pan that produced the gray loaves was not perforated.
Ingredients and preparation, except for forming three loaves, are exactly the same. I'm not sure whether I've learned anything or simply confused matters even further.