If I'm looking to make my pastry recipes a little healthier, should I use unbleached flour instead of the bleached kind?
-- Sarah Sholter
Those two flours will yield the exact same nutritional profile for your recipes.
The difference between them simply lies in their processing.
Bleached flour is whitened with a variety of chemicals, while unbleached flour retains its off-white color and is only matured by the addition of ascorbic acid (vitamin C) and exposure to air.
Maturation is the term used to describe the "aging process" in which flour is stored after undergoing milling.
It is during this period that flour gains its structural properties that make it most suitable for baking.
Bleached flours' maturation times are significantly sped up due to the usage of chemicals. Whereas unbleached varieties may take four weeks to fully mature, bleached flours can mature in as little as 48 hours.
Although neither is nutritionally superior to the others, some consumers prefer unbleached flour as it is not in contact with a variety of chemicals.
If you are looking to boost the fiber content of your pastries, I suggest using whole wheat pastry flour (either as the only source of flour in your recipes or as a subtitute for half the amount of traditional pastry flour.)