GIFSQ Tools · Module 05 — Cereal, Grain, Flour & Milling Technology · Tool 095 of 500
Analyse a Chopin alveograph curve: enter tenacity (P), extensibility (L) and baking strength (W) to get the P/L ratio and the flour class.
Try sample values — fills the form with the worked example below.
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P / L ratio
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W (× 10⁻⁴ J)
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P (mm H₂O)
Equation: P/L ratio = P ÷ L, where P is tenacity in mm H₂O and L is extensibility in mm. W, the baking strength in 10⁻⁴ J, is the area under the alveograph curve, read from the instrument.
Method: Chopin alveograph, ICC 121 and AACC 54-30. A dough disc is inflated into a bubble until it bursts; P is the maximum pressure (tenacity), L is the bubble length at bursting (extensibility), and W is the energy needed to inflate it (baking strength).
Assumptions: the dough was prepared at the standard hydration and rested as the method prescribes; P, L and W are from the same test run.
Limitations: the W bands are guides, not specification limits; the alveograph measures biaxial extension, which suits some products better than others; results shift with dough hydration and salt.
Rounding: P/L ratio to 2 decimal places; P and L to 1 decimal place; W as entered; intermediates unrounded.
This is a calculation aid, not a laboratory report — confirm against your accredited method before citing a value.
Method: Chopin alveograph, ICC 121 and AACC 54-30. A dough disc is inflated into a bubble until it bursts; P is the maximum pressure (tenacity), L is the bubble length at bursting (extensibility), and W is the energy needed to inflate it (baking strength).
Assumptions: the dough was prepared at the standard hydration and rested as the method prescribes; P, L and W are from the same test run.
Limitations: the W bands are guides, not specification limits; the alveograph measures biaxial extension, which suits some products better than others; results shift with dough hydration and salt.
Rounding: P/L ratio to 2 decimal places; P and L to 1 decimal place; W as entered; intermediates unrounded.
This is a calculation aid, not a laboratory report — confirm against your accredited method before citing a value.
Worked example: P = 85 mm H₂O, L = 110 mm, W = 280 × 10⁻⁴ J. P/L = 85 ÷ 110 = 0.77. W of 280 is a strong flour, suited to bread.
Enter values above to see results.
W guide: under 150 weak (biscuits), 150–250 medium, 250–350 strong (bread), over 350 very strong. Bread flour usually has P/L near 0.5–0.9. Tool 095 of 500 — GIFSQ
