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
Quick to prep and packed with flavor, this dish is a bold way to kick up any weekend spread.
University of Nebraska-Lincoln President Dr. Jeffrey Gold talks about heart health and preventive care for viewers in rural communities.
Shrinking slaughter capacity may delay heifer retention, complicating herd rebuilding plans.
Tennessee State Veterinarian Dr. Samantha Batey joined us with the latest on biosecurity efforts and the state’s new “Know Before You Show” initiative.
Winter Weather And Markets Reshape Agriculture Nationwide This Week

LATEST STORIES BY THIS AUTHOR:

Farm legal expert Roger McEowen discusses the EPA’s rescission of the 2009 endangerment finding on greenhouse gases and what it could mean for agriculture and rural America.
Chef and influencer Marcia Smart joined us to discuss Italian-inspired beef dishes, nutrition for active lifestyles, and how global events shape home cooking.
The USDA says the framework is about “ending abusive government overreach” and “protecting farmers, families, and private property.”
Farm numbers still favor small operations, but production, resilience, and risk management are increasingly concentrated among fewer, larger farms.
Wed, 2/18/26 – 7:30 PM ET
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.