Alveographs

An alveograph is a laboratory instrument used to assess the rheological properties of dough by inflating a sheet of dough until rupture. A small film of dough is prepared and placed over an opening in a chamber, then clamped at the edges. Air is gradually supplied to inflation, and the dough’s resistance to expansion and its ultimate extensibility are recorded as a curve.

From the curve, three main parameters are extracted: P, the maximum overpressure during inflation, which reflects dough tenacity or resistance to deformation; L, the extent to which the dough can stretch before rupture, representing extensibility; and W, the area under the curve, indicating the overall energy required to rupture the dough and providing an integrated measure of dough strength. The ratio P/L is commonly used to summarize the balance between tenacity and extensibility.

Interpretation and use: Higher P indicates a stronger, more resistant dough, while higher L indicates greater stretchability. W correlates with the overall strength of the gluten network and its gas-retaining capacity. Alveographic data are used to classify flours for different bread types, to guide formulation and processing decisions, and to predict baking performance such as loaf volume and crumb structure. It is often used in conjunction with other rheological tests to obtain a comprehensive view of dough behavior.

The alveograph method is standardized in international cereal science guidelines and is widely used in flour quality control, product development, and research. Equipment is manufactured by several suppliers, and results are used by mills, bakeries, and research laboratories to compare flour lots and optimize baking performance.