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
On a spreadsheet, it looks like the ultimate way to harvest extra profit. But in the eyes of the IRS—as RFD-TV Farm Legal & Tax Expert Roger McEowen explains—this “tax-free” bank can quickly turn into a field full of weeds.
Bigger cows must wean proportionally heavier calves to justify higher ownership costs.
Read the full press release published by the U.S. Department of Agriculture.
Lily Pryer’s passion shows how National FFA members are making an impact in classrooms and communities all across Rural America.
Farmer Bridge Assistance payments provide immediate balance-sheet support heading into 2026, but remain a short-term bridge rather than a substitute for long-term market recovery.
The New Year is here, but in Oregon, some ranchers and livestock producers are still trying to recover from record wildfires back in 2024.

LATEST STORIES BY THIS AUTHOR:

Sen. Amy Klobuchar has four years remaining in her Senate term and could decide to continue serving in that role while campaigning for Governor of Minnesota.
STRAUSS CEO Henning Strauss joined us with a preview of “Meet Strauss: The Tool You Wear,” premiering live tonight at 7:30 ET — only on RFD Network and RFD+
FarmHER Chris Nellis and her daughters navigate loss while carrying on a 300-year farm legacy, milking cows in upstate New York.
USDA Undersecretary for Trade and Foreign Agricultural Affairs Luke Lindberg joined us with a recap of the Malaysia trade mission and a look at USDA’s broader trade strategy moving forward.
Mike Steenhoek of the Soy Transportation Coalition shares how extreme winter weather is affecting the ag transportation network and what producers should keep in mind as conditions slowly improve.
Matt Brockman, Communications Director for the Fort Worth Stock Show and Rodeo, joined us with a look at how the legendary event is moving forward—weather and all.
Agriculture Shows
Special 3-part series tells the story of the Claas family’s legacy, which changed agriculture forever.
From soil to harvest. Top Crop is an all-new series about four of the best farmers in the world—Dan Luepkes, of Oregan, Illinois; Cory Atley, of Cedarville, Ohio; Shelby Fite, of Jackson Center, Ohio; Russell Hedrick, of Hickory, North Carolina—reveals what it takes for them to make a profitable crop. It all starts with good soil, patience, and a strong planter setup.
Champions of Rural America is a half-hour dive into the legislative priorities for Rural America. Join us as we interview members of the Congressional Western Caucus to learn about efforts in Washington to preserve agriculture and tackles the most important topics in the ag industry on Champions of Rural America!
Featuring members of Congress, federal and state officials, ag and food leaders, farmers, and roundtable panelists for debates and discussions.