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
Dr. Sally DeNotta with the American Association of Equine Practitioners (AAEP) provides horse owners with guidance on the recent outbreak of Equine Herpes Virus (EHV).
Rooster is a full-time farmhand, right-hand man on Shawn Raff’s cattle and dairy operation in Eatonton, Georgia.
Milk output is rising, but steep drops in Class I–IV prices are tightening margins heading into 2026.
Weaker U.S. dairy prices come as value-added exports expand and ingredient inventories tighten, creating mixed market signals for producers.
Dr. Jeffrey Gold, President of the University of Nebraska, joined us to break down what telehealth entails and which conditions can be managed through remote appointments.
While the agriculture industry hoped details on proposed “bridge” payments for farmers would be released this week, Ag Secretary Brook Rollins said the USDA is still working with the White House on the finer points.

LATEST STORIES BY THIS AUTHOR:

President Donald Trump speaks at the World Economic Forum in Davos, addressing SNAP spending, tariff threats against Europe, market reactions, and the upcoming USMCA review.
From meatpacking settlements to landmark NEPA rulings, Roger McEowen outlines the top legal developments in 2025 that will shape agriculture in the years ahead.
Alan Bjerga with the National Milk Producers Federation joined us to review new policies and regulations supporting the dairy industry and what they mean for the year ahead.
Despite rising costs and growing food insecurity, meat demand remained strong in 2025 as higher-income consumers offset cutbacks elsewhere. Economists break down the K-shaped economy, upcoming USDA cattle reports, livestock production outlooks, and renewed debate over beef imports and country-of-origin labeling heading into 2026.
Corn growers are turning to ethanol, E15 expansion, and export markets to help absorb record supplies and stabilize prices. Farm leaders discuss low-carbon ethanol demand, flex-fuel vehicle challenges, input costs, and the role of USMCA as producers look for market relief in the year ahead.
From rising trade tensions in Europe to a pending Supreme Court decision on tariffs and shifting demand from China, global trade policy spearheaded by President Donald Trump continues to shape the outlook for U.S. agriculture—adding uncertainty as farmers navigate another volatile year.
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.