Extensigraph

Method

Preparation
1. A 300-gram flour sample on a 14 percent moisture basis is combined with a salt solution and mixed in the farinograph to form a dough.
2. After the dough is rested for 5 minutes, it is mixed to maximum consistency (peak time).


Analyses
1. A 150-gram sample of prepared dough is placed on the extensograph rounder and shaped into a ball.
2. The ball of dough is removed from the rounder and shaped into a cylinder.
3. The dough cylinder is placed into the extensograph dough cradle, secured with pins, and rested for 45 minutes in a controlled environment.
4. A hook is drawn through the dough, stretching it downwards until it breaks.
5. The extensograph records a curve on graph paper as the test is run.
6. The same dough is shaped and stretched two more times, at 90 minutes and at 135 minutes.

Results
• The extensograph determines the resistance and extensibility of a dough by measuring the force required to stretch the dough with a hook until it breaks.
• Extensograph results include resistance to extension, extensibility, and area under the curve.
• Resistance to extension is a measure of dough strength. A higher resistance to extension requires more force to stretch the dough.
• Extensibility indicates the amount of elasticity in the dough and its ability to stretch without breaking.
• Extensograph curves are described on pages 48.
Why is this important?
Results from the extensograph test are useful in determining the gluten strength and bread-making characteristics of flour. The effect of fermentation time and additives on dough performance can also be evaluated.