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. Deb Vnoverbeke, UNL’s Head of Animal Science, joins us with more about the university’s experiential learning programs designed to prepare veterinary students for the future of agriculture.
New SDRP funding and expanded loss programs give producers additional tools to rebuild cash flow and stabilize operations after two years of severe weather losses.
Here is a regional snapshot of harvest pace, crop conditions, logistics, and livestock economics across U.S. agriculture for the week of Monday, November 17, 2025.
UMN Extension’s Emily Krekelberg outlines today’s top farm stressors, key signs of mental health distress in rural communities, and the resources available for support.
The ACRE Act modestly reduces farmland borrowing costs now, with more savings possible once federal guidance clarifies which loans qualify.

LATEST STORIES BY THIS AUTHOR:

The federal government’s status is far from the only factor moving the markets on Friday. Two critical reports released today on producer inflation and the status of the U.S. cattle herd are also top of mind.
Brent Graves of StockShowAuctions.com takes us to Grayson County to see the damage from a historic winter ice storm and what it will take to rebuild.
UT Extension also offers tips to help consumers stretch their grocery budgets, including meal planning, sticking to a shopping list, and choosing store or generic brands.
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+
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.