Flour & Dough Rheology
Product & Ingredient Quality

Commercial Bakers - Analyze Your Flour to Predict Bread Height

Many baked goods consumers eat with their eyes. When something seems “off” about their bread product – such as uniform size, shape, volume, color, texture, and many other visual traits – it can impact their entire experience. It is up to the baking operation to deliver a consistent product with the attributes that consumers expect.

Nevertheless, flour is a dynamic ingredient. The milling process, the harvest season, how the flour is stored, and other variables can all impact flour quality. As this article explains, one of the ways for bakers to know how a specific flour will adapt to produce an ideal product is to put it through the baking process and hope for the best outcome.

However, flour and dough rheological tools are available to help bakers obtain baseline expectations to ensure their ideal outcome. In a relatively short testing time and a small flour sample, bakers can acquire essential flour adaptability data to determine whether a specific batch of flour can proceed with production. Not only does this serve to control quality, but rheological instruments help bakeries save ingredients, reduce waste, and make confident process decisions.

Not All Rheological Analyzers are Created Equal

Rheological analyzers have been present in the milling and baking industries for several decades, yet there are clear differences between them. Two of the most well-known instruments are the Farinograph® and the Mixolab 2 Universal Dough Characterizer from KPM Analytics. Many in the baking industry may consider these tools interchangeable with one another – this is simply untrue.

While it is true that both instruments provide an accurate measurement of water absorption and mixing properties, only the Mixolab 2 carries the analysis beyond the early mixing process stages to thoroughly analyze flour behavior. This extra information is especially critical for predicting final product attributes like bread height.

How Does Mixolab 2 and a Combination of Rheological Instruments Compare on Predicting Bread Height?

In an internal study, 11 different batches of wheat flour were put through the same baking process. After baking and cooling, each loaf was analyzed for baking height (mm) and oven spring.

Figure 1: Eleven loaves of bread from baking tests using different flour batches were measured height (mm). This served as the control data for the analysis trials of Mixolab 2 and the combination of rheological instruments (Farinograph and Extensograph). Data table shown below.
Table 1
Flour Sample Bread Height
Sample A 150
Sample B 152
Sample C 167
Sample D 160
Sample E 155
Sample F 158
Sample G 154
Sample H 145
Sample I 147
Sample J 146
Sample K 152

Next, each flour from the baking test analysis was put through analysis between a combination of rheological products (referred hereafter as “combo test”) and the Mixolab 2.

In the “combo test,” data from a Farinograph® was combined with data captured from a subsequent Extensograph® test. Between these two tests, the experimenter could predict the bread height by comparing the data against the control.

On the other hand, the Mixolab 2 test could perform the entire analysis process with a single test using a smaller flour sample size. This is because the Mixolab 2 tests attributes beyond mixing properties, including:

  • Protein weakening: Relating to final bread volume and other features
  • Starch gelatinization: Also relating to bread volume as well as crumb structure
  • Enzymatic hydrolysis: Relating baking stability with amylase activity
  • Starch retrogradation: An indication of bread shelf life

Conclusion: Mixolab 2 Results Provide Significantly More Information allowing to better anticipate Bread Height – and at a Fraction of Analysis Time

When comparing data sets from the “combo test” and Mixolab 2, the results showed that Mixolab provided more robust data that aligned more strongly with the controlled results (Figure 2), whereas the combination of the Farinograph® and Extensograph® testing (Figure 3) were significantly less reliable.

Figure 2: Mixolab 2 testing results against the control.
Figure 2: Mixolab 2 testing results against the control.

Figure 3: "Combo tests" against the control.

Furthermore, the Mixolab 2 testing process was significantly less time consuming and cumbersome compared to the “combo test” products:

Analysis time for Mixolab 2 for one sample: 45 minutes total

  • Total time for all 11 samples: 8 hours, 25 minutes

Analysis time for “combo test” for one sample:

  • Farinograph®: 1 hour
  • Extensograph®: 1 hour 30 minutes (in mini mode)
  • Total for one sample: 2 hours, 30 minutes
  • Total time for all 11 samples: 27 hours, 30 minutes

This means, when it comes to predicting bread height of incoming flour, Mixolab 2 is an effective all-one-tool that is 3.4X less time consuming and provides 65% more information than the combination of Farinograph® and Extensograph®. However, Mixolab 2 is not just a more thorough way to predict bread height – the same protocol can be used to assess almost any visual property of baked products (volume, crumb structure, etc.).