Measuring texture of dough - extension, inflation and stress relaxation

Bread is one of the oldest foods in human history, and it has lost none of its relevance. In the UK, bread and snack products continue to dominate the top grocery brands, and the bakery market remains fiercely competitive - with thousands of product variations vying for space on shelf and in consumers' shopping baskets. In that environment, one thing separates the brands that hold loyalty from those that don't: consistent quality. And at the heart of quality is texture.

Why dough rheology matters more than you might think

For food scientists working in bakery, the finished loaf is in many ways already determined long before it goes anywhere near an oven. By the time a dough has been mixed, its rheological characteristics are set. The interactions between flour, water, yeast and air during mixing establish the structural framework that will govern everything from crumb texture to crust development to shelf-life perception.

This means that investing in thorough physical characterisation at the earliest stages of production isn't just good practice - it's a direct lever on efficiency and quality. Catching a formulation issue in the dough stage is infinitely less costly than discovering it in the finished product. In a market where brand loyalty is hard-won and consumer expectations are exacting, there's little margin for error.

The problem with traditional testing methods

Standard physical characterisation methods - such as those following AACC protocols - typically require large quantities of dough and are time-consuming to run, making them impractical in many manufacturing and R&D contexts. For wheat breeders and early-stage researchers in particular, the ability to work with smaller sample sizes is often essential, as only limited quantities of experimental flour may be available.

A more practical approach to dough inflation testing

The Dobraszczyk/Roberts Dough Inflation System from Stable Micro Systems was developed to address exactly these limitations. Designed to attach to the TA.XTplusC Texture Analyser, it recreates the strain conditions experienced around a slowly expanding gas cell in dough - one of the most fundamental processes in bread production - in a way that is both time-efficient and capable of working with smaller sample sizes than traditional methods require.

A sheet of dough is inflated by air volume displacement inside a customised temperature chamber, which can maintain controlled temperatures of up to 60°C. This chamber serves a dual purpose: housing the sample during its pre-test equilibration period, and providing the controlled thermal environment needed for a realistic assessment of how dough will behave during proving.

Pressure and volume are measured continuously throughout inflation, and from these values key parameters can be derived - including the strain hardening index of the dough. This is particularly valuable as an early warning indicator: a dough with poor strain hardening characteristics is more likely to deform unexpectedly during processing, and identifying this at the formulation stage allows manufacturers to intervene before it becomes a production problem.

Extensibility and viscoelastic balance

Alongside inflation testing, extensibility measurements using the Kieffer Dough & Gluten Extensibility Rig offer further insight into the viscoelastic balance of the dough - a critical factor as pieces are separated and rounded on the line. A dough that is too elastic resists manipulation and tends to produce misshapen loaves; one that is too viscous lacks the structural integrity to hold the crumb open. Resistance to extension and extensibility together give a strong indication of how a dough will respond to the baking process, and whether the finished product will meet expectations for texture and appearance.

For research teams and wheat breeders working with experimental varieties or limited flour stocks, the ability to obtain this level of insight from smaller sample sizes makes the Kieffer Rig a particularly practical addition to the testing toolkit.

Further reading

For a broader look at the full range of texture analysis applications in bread and bakery product development, explore Stable Micro Systems' bakery applications pages, or find out more about how a Texture Analyser works if you're new to the field.