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
Initiative brings students from different backgrounds together to build relationships and broaden perspectives
March 15 of each year is the application deadline for the Pima Cotton Trust, and March 1 of each year is the application deadline for the Wool Trust. The law mandates trust payments by April 15. More information about these programs is available at www.fas.usda.gov/programs.
Tractor Supply’s Paper Clover Campaign raises millions of dollars each year for 4-H youth programs and scholarships. Local store community marketing manager Lexie Gamble joined Tuesday’s Market Day Report alongside 4-H student Matthew Rochford to discuss the partnership.
Alan Bjerga with the National Milk Producers Federation discusses how stewardship is driving efficiency, profitability, and competitiveness in the dairy industry.
U.S. Secretary of Agriculture Brooke Rollins announced the availability of over $275 million in grant funding in FY2026 for the specialty crop industry in the United States through three USDA programs.
University of Tennessee Institute of Agriculture students traveled to Italy to study Roman and medieval construction, gaining a unique global educational experience.

LATEST STORIES BY THIS AUTHOR:

Strong demand for U.S. beef in Mexico is boosting exports, with buyers seeking both variety meats and high-quality cuts like Prime and Choice ribeye.
Rep. Dusty Johnson of South Dakota joined us to discuss rising input costs, proposed fertilizer legislation, and potential support for farmers navigating tight margins.
Lewis Williamson with HTS Commodities joined us to discuss the latest crop progress report and how market uncertainty and input costs are shaping planting decisions this spring.
The Farm Monitor takes us along to see how they’re leaning on technology to improve poultry production.
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.