Decoding DOS, HVK, and WOOCs: Key Factors in Grain Grading
Grain grading is a critical step in determining market value, processing quality, and end-use performance. Among the many grading factors assessed, Degree of Soundness (DOS), Hard Vitreous Kernels (HVK), and Wheats of Other Classes (WOOCs) play a crucial role across the entire grain supply chain—from farmers and grain handlers to millers and exporters.
Understanding these factors ensures consistent quality, reduces disputes, and optimizes processing decisions at every stage. Let’s take a deeper look at what they mean and why they matter.
What is Degree of Soundness (DOS)?
DOS evaluates the overall condition of wheat kernels, focusing on damage, weathering, and other defects that can impact milling and processing performance. Environmental factors such as excess moisture, frost, heat stress, and disease can all affect a kernel’s structural integrity and flour yield.
Why It Matters
Sprouting reduces baking performance and starch quality.
Heat & Frost Damage affects milling efficiency and flour colour.
Mildew & Mottling can indicate spoilage, leading to rejection.
A high DOS rating means better grain quality, fewer processing losses, and improved end-use performance, making it a key factor for buyers, processors, and grain exporters.
Source: weeklytimesnow.com.au
Hard Vitreous Kernels (HVK): A Key Quality Indicator
HVK measures the percentage of kernels that are hard, glassy, and fully developed, particularly in Canadian Western Amber Durum (CWAD) and Canadian Western Red Spring (CWRS) wheat.
Why It Matters
Higher HVK levels indicate stronger gluten, crucial for pasta and bread production.
Low HVK levels suggest immature kernels, affecting flour consistency.
Buyers use HVK to determine blending requirements and predict milling outcomes.
HVK is often assessed visually, meaning grading accuracy is critical in ensuring consistent wheat quality and marketability.
Source: Canadian Grain Commission
Wheats of Other Classes (WOOCs): Ensuring Purity in Grain Shipments
WOOCs refer to wheat kernels from different classes present in a grain sample. Different wheat classes have unique protein content, gluten strength, and milling characteristics, making purity a key factor in grading.
Why It Matters
Affects flour consistency – Mixing wheat classes leads to variability in baking performance.
Impacts contract specifications – Grain shipments must meet strict WOOC limits to avoid penalties.
Influences blending decisions – Processors need accurate WOOC data to maintain product quality.
For example, excess soft wheat in a CWRS shipment could lower protein levels, impacting its value and intend use. Keeping WOOCs within acceptable limits ensures quality consistency across the supply chain.
Source: Grains Canada.
Bringing Consistency to DOS, HVK, and WOOC Assessments
Traditional grain grading relies on human interpretation, which introduces subjectivity and inconsistency when assessing DOS, HVK, and WOOCs. Our automated grain grading with AI, near-infrared spectroscopy, and Machine Vision offers:
✔ Standardized grading – AI ensures consistent analysis, reducing grader variation.
✔ Real-time insights – Instant assessments allow for faster decision-making.
✔ Greater accuracy – Large sample sizes provide a more representative grain quality assessment.
Using our benchtop MV/NIRS system helps farmers, grain buyers, processors, and exporters evaluate these critical grading factors with precision, efficiency, and confidence.
Want to see automated grain grading in action? Book a demo today.