Pastry Flour (T45)

T45 represents the most refined, lowest-mineral flour in the French grading system, where the number refers to ash content in milligrams per 10 grams of dry matter—T45 contains roughly 450 milligrams of minerals. Milled from soft wheat with a protein content of just 7–9% and an extraction rate of approximately 50–55%, T45 produces a flour of exceptional fineness. The low protein means minimal, weak gluten development when hydrated, which gives pastry doughs their characteristic tenderness rather than chew.

This weak gluten structure is the defining characteristic that makes T45 indispensable for French pastry. When combined with cold butter and minimal handling, the flour creates doughs where fat coats starch granules without forming tough protein networks. The result is pastry that shatters cleanly on the fork, holds delicate shapes with precision, and delivers a melt-in-mouth quality impossible to replicate with higher-protein flours. Its fine texture also ensures smooth batters and doughs without a grainy mouthfeel.

T45 is standard in French pastry kitchens, produced under the French milling and classification system. It differs fundamentally from American flour grading, which classifies by protein rather than mineral content. It is not a substitute for bread flour or even standard all-purpose in applications where structure matters, but for tart shells, fine cookies, and laminated doughs where tenderness is paramount, it is the professional standard. The trade-off is a shorter shelf life—6 to 12 months—because the higher fat content of soft wheat makes T45 more prone to rancidity than hard wheat flours.