Milk Classes: What are they and what’s the difference between them?

Milk classes are often included in market reports, but what does that mean?

Milk is categorized into grades and classes based on its intended use and quality standards. But what’s the difference, and why do they matter?

What is a Milk Grade?

Milk grades denote the quality of the milk product and its suitability for either consumption or use in manufactured products like butter and cheese. There are two primary grades of milk: A, B, and AA.

  • Grade A: The highest grade, suitable for direct consumption as fluid milk. It meets stringent health and sanitation standards. Grade A milk is the only type sold as fluid milk for direct consumption.
  • Grade B: Used for manufacturing products like cheese, butter, and dry milk powder. It does not meet the same quality standards as Grade A.
  • Grade AA: This applies specifically to milk used for butter production. While Grade B milk can also be used for butter production, Grade AA is the highest grade for butter based on flavor, quality, and texture.

What is a Milk Class? What’s the difference between milk Classes I-IV?

The Federal Milk Order System uses four classes to categorize milk based on its end use rather than quality. These classes are often included in dairy market reports, but what is the difference between each of the four classes?

CoBank dairy economist Corey Geiger shares an easy way to remember the difference between different classes of milk products:

  • Class I: “Class I is beverage milk, it’s what you drink,” Geiger says.
  • Class II: “Class II is all the soft products,” he explains. “Think: ice cream, yogurt. Cottage cheese would [also] be in there because it’s a softer cheese, and the creamers that you see in coffee.”
  • Class III: “Class III is the largest class of milk, and it includes cheese and whey,” Geiger explains. “I always tell people we think of a nursery rhyme, ‘Miss Tuffett sat on her muffin, eating her curds and whey.’ Curds and whey are all of Class III.”
  • Class IV: “Class IV is butter and dry milk powders. Dry milk powders and non-fat dry milk are a key export. We export the product throughout the countries around the world, so those are Class III and IV.”

Geiger says Class 4 saw a big jump last year. Butter production was also the highest it has been in 77 years.

Related Stories
David Fisher with the American Lamb Board joined us to discuss a new sustainability program designed to boost producer profitability while supporting stewardship practices.
First-grade teacher Taylor Dougherty at Eastern Elementary School was named the 2026 Ag in the Classroom Award winner for her efforts to teach students about agriculture.
David Gruchot with USDA APHIS joined us to discuss the growing threat of invasive pests and the steps individuals can take to help protect U.S. agriculture.
Seafood producers gain expanded access to USDA support programs.
Lawmakers say payments will support schools, infrastructure and public safety in rural communities.
Risk management and diversification improve survival odds. Heidi Exline with American Farmland Trust discusses barriers to farmland access and efforts to connect the next generation of producers with retiring farmers.

LATEST STORIES BY THIS AUTHOR:

The massive Morill wildfire left Nebraska ranchers facing major losses, as relief funds and federal aid step in to support recovery efforts.
Led by Sen. Rand Paul, lawmakers aim to prevent a November federal hemp ban, advocating for state control as farmers face planting uncertainties.
U.S. Rep. Dusty Johnson of South Dakota joined us to discuss rising input costs, fertilizer transparency efforts, and the role of trade in supporting farmer profitability.
U.S. Secretary of Agriculture Brooke Rollins joined us to discuss fertilizer markets, domestic supply efforts, trade priorities, and ongoing policy work aimed at stabilizing costs for U.S. farmers.
Louisiana State University Professor Shelly Pate Kerns says a late freeze forced widespread replanting of some crops across the state.
Agriculture Shows
Hosted by Scott “The Cow Guy” Shellady and RFD News Markets Specialist Tony St. James, Commodity Talk delivers expert insight into the day’s ag commodity markets just before the CME opens. Only on RFD-TV and Rural Radio SiriusXM Channel 147.
A look at the news, weather and commodities headlines that drove agriculture markets in the past week.
Everything profits from prairie. Soil, air, water — and all kinds of life! Learn how you can improve your land with prairie restoration, cover crops and prairie strips, while growing your bottom line.
Special 3-part series tells the story of the Claas family’s legacy, which changed agriculture forever.