Oxidation

Oxidation is oxygen doing work you may not want: bleaching flour pigments, turning oil stale, flattening wine. Some oxygen is inevitable. Intensive mixing and sloppy storage invite more.

Dough color and aroma #

King Arthur’s autolyse teaching, following Calvel: aggressive mixing in mid-century French shops oxidized carotenoid pigments in the flour, leaving bread paler, with less aroma and flavor, even when volume was high ¹. Calvel’s answer was less mechanical abuse and a flour-and-water rest, not a bleaching agent ². Look at crumb: creamy versus chalk-white. Smell: wheaty versus nothing. Mixing is the lever. Gluten still needs some work; more is not browner.

Oil that failed the nose #

USDA AMS extra virgin requires excellent flavor and odor — median of defects equal to zero, fruitiness greater than zero — and a free fatty acid limit of 0.8 grams per 100 grams as oleic acid ³. Rancid, fusty, or musty oil is a defect. Free fatty acid is a chemical grade limit, not a tasting-wheel synonym for “peppery.” Taste method: Olive oil tasting. The substance: Fat.

Whole-grain flour goes off the same way when germ oil ages. The milling page’s observation still holds: rancid germ smells like old nuts. That is storage, not starter.

What to do #

Store oils cool, dark, and closed. Mix dough enough to organize gluten, not enough to make it white for its own sake. Do not invent peroxide values beyond what a grade table already states. Tasting is how you catch the defect while you can still throw the bottle out.