Getting up from falling numbers

December 2013, Wheatlife

by Trista Crossley

In some years, wheat farmers have to worry about disease destroying their crops. In other years, it can be pests, drought or other weather-related events. In really bad years, it can be all of the above. This year, the big bad in the Pacific Northwest was low falling number scores likely caused by preharvest sprouting due to rain.

Wheat begins to sprout when wet weather breaks mature kernels out of dormancy and germination begins, degrading the kernel’s starches. If this process happens before harvest, the quality of the wheat is downgraded and discounted.

While wheat that has sprouted can be identified visually, the earliest stages of sprout initiation, indicated by increased alpha-amylase activity inside the kernel, cannot. That’s where the falling number test comes in. The test uses a slurry of boiling water and flour to measure how long it takes a plunger to move through it. The faster the plunger moves, the more alpha-amylase is present and the lower the falling number score. A number below 300 for soft white can result in producers receiving discounts for their wheat. In other classes, discounts kick in at 300 for hard red winter and 330 for hard red spring.

The amount of alpha-amylase is important because too much of the enzyme breaks down the wheat’s starches which can adversely affect the flour’s end-use qualities. In other words, bread won’t rise properly, cakes collapse and noodles turn mushy. Bakers can compensate for flour that has too little alpha-amylase (a high falling number score), but they can’t remove existing enzymes from the flour.

The problem with the falling number test is that it can be inconsistent (different tests on the same batch of wheat can yield different scores), and other factors besides the presence of alpha-amylase can sometimes trigger a low falling number.

“Falling Number Blues” was the name of an educational breakout at the Tri-State Grain Growers Convention. Five panel members from various parts of the grain industry addressed different aspects of the falling number test and its effect on both buyers and sellers. Read more

Washington State University