In Part I, I focused on fundamental food safety and quality issues of vomitoxin and falling numbers. These concerns, when they exist, take priority because wheat is a food grain. People eat products made from flour, so wheat is held to higher quality standards than feed grains and oilseeds. However, wheat and flour quality concerns do not end there. In fact, we have yet to explore the most interesting aspects of wheat and flour quality.
Let’s return to my comparison of two different products made with wheat flour; bagels and cakes. What is it about wheat flour that gives the bagel a dense chewy texture, while the cake has a light, foamy texture? The answer is gluten content - gluten being a protein complex that accounts for 75 to 85% of the total protein in bread wheat. Gluten and protein are essentially synonymous terms in the world of wheat. Bagels and cakes are a great contrast, because they are flour-based products that represent opposite ends of the protein spectrum. A good bagel demands a high gluten flour, usually made from hard red spring wheat, with a protein content of 15% or higher. By contrast, cake flour demands a low gluten flour, generally made from soft wheat, with a protein content of 9% or lower.
Look at the world of wheat flour products and place them into two separate groups; flour based products that need to rise and enlarge, and products that are relatively flat. Bread and rolls need to rise and expand – they need more gluten. In general, the more exotic the bread (multi-grain, whole grain, etc.) the more gluten and protein needed. Now think about the flat products like crackers, cookies, pretzels, etc. These products are made with lower protein flour. You’re now developing a sense for a broad spectrum of protein needs to make a broad variety of products.
So, you think, it’s all about the protein. Oh, if it were only that simple. Protein is important but depending if you are a wheat producer or a flour user, there are other quality factors to consider. When a wheat producer thinks about a high quality wheat, they think first of yield. Protein content is also important. Depending on the year, protein premiums or discounts may exist for levels above or below 14%. Other quality factors beyond protein content come into play with the producer’s desire to avoid quality discounts. They also think about disease resistance (vomitoxin!), sprout resistance (falling numbers!), test weight and other types of damage. This is a source of frustration for wheat producers; beyond the possibility of a protein premium, the market for wheat is generally ruled by a system of quality discounts.
When a baker – the wheat flour user - thinks about high quality, they have a different list. For example, absorption is, in effect, the bakers take on yield (higher absorption means more loaves of bread from a cwt of flour). Bread makers also look at loaf volume and mixing tolerance (and protein content is important here). They also use the catch-all phrase “performance,” which looks beyond the measurable, and asks, “Can I make a good product?” Last, but not least, the baker insists on flour consistency, which the miller achieves through blending, blending and more blending.
You may have already noticed that the only factor where the two sides talk a common language is protein. The following graph shows the negative relationship between protein premium in the Minneapolis market and protein content in the North Dakota spring wheat crop. I use a two-year average of protein because of large carryovers of spring wheat from one year to the next (since 2000, the average carryover of HRS wheat has been 33% of usage). One good year of high protein wheat will not necessarily “break” the premiums because a large carryover from the year before may be primarily lower protein wheat. The opposite can also occur – one year of low protein will not necessarily lead to wildly higher protein premiums if the carryover from the previous year is high in protein.
Protein content will remain the main quality factor because it is the only quality factor with which the farmer, grain elevator, miller and baker speak a common language. However, the baker is not so much interested in protein content as much as they are in the flour qualities delivered by higher protein - better absorption, better loaf volume and better mixing tolerance. How does the miller assure the baker that the protein they buy is delivering these key flour quality factors? Every year, millers will conduct an extensive survey of new crop wheat, complete with bake testing of wheat samples.
The issue of wheat and flour quality is complicated. I hope I gave you something to ponder as you enjoy your next bite of a bagel - or cake.
Data sources: The Minneapolis Grain Exchange and the North Dakota Wheat Commission
About the author:
Edward Usset serves as a Grain Marketing Economist at the University of Minnesota, where he teaches "Commodity Markets" and travels broadly to discuss marketing plans and strategies with grain producers. He is also a regular columnist for Corn and Soybean Digest. Prior to his work with the University, he served 12 years in the milling division of The Pillsbury Company, where he purchased wheat and sold wheat flour. The 2nd Edition of his book, “Grain Marketing is Simple (it’s just not easy)” was released in November, 2015.