Pro Tip: It is essential to understand the many ways in which particle size impacts the performance of flour in baked goods.

In the world of milling and baking, flour quality is everything. While protein content and enzyme activity often dominate conversations about flour functionality, particle size is an increasingly crucial — and sometimes overlooked — parameter influencing everything from water absorption to final product texture.

A recent review by Dziki, et al.¹ in Processes brings welcome attention to particle size as a powerful quality indicator, drawing from more than five years of global research. Their findings highlight the diverse ways that particle size impacts the performance of flour in bread and cookies, often in surprising ways.

For bakers, the sweet spot of particle size isn’t always intuitive. Coarser flour fractions, for instance, tend to produce bread with higher volume and softer crumb — but only to a point. Finer flour offers higher water absorption and improved gluten development, but over-milling may damage starch and generate heat, both of which compromise dough structure and nutritional quality.

This delicate balance shows up across the data: breads made with flour around 600 µm particle size often outperform both finer and coarser counterparts in terms of volume and crumb softness.

Cookie manufacturers also face trade-offs. Coarse flour yields cookies with more spread and a crisp texture, while finer flour increases dough density and reduces expansion — a challenge for uniformity and bite.

It’s important to note that particle size doesn’t act alone. Dziki and colleagues emphasize that differences in chemical composition across size fractions — especially in protein and phenolic content — can confound results. This is particularly relevant in whole wheat and bran-enriched products, where fiber and bioactive compound content varies across particle classes.

With advancements in grinding technologies like jet and ball milling, we now have greater control over particle size distribution and its downstream effects. But with that power comes responsibility. Optimizing particle size for product-specific outcomes — not just blindly chasing finer flour — should be a priority in both mill and bakery settings.

As the industry continues to move toward clean label, whole grain and functionally enriched products, a deeper understanding of how particle size influences flour performance is essential. The future of flour is not just in its proteins or starches, but in the invisible curve of its granulation profile.

Reference

¹Dziki, D.; Krajewska, A.; Findura, P. (2024). “Particle Size as an Indicator of Wheat Flour Quality: A Review.” Processes, 12(11), 2480. https://doi.org/10.3390/pr12112480.

Dr. Senay Simsek, serving as the department head, professor and dean’s chair in food science at Purdue University, possesses a background in cereal science, technology and wheat quality. Her goal is to foster collaboration between producers, scientists and food processors, optimizing research potential in this area.