Butter as outlined in Wisconsin law refers to the clean, non-rancid product made by gathering the fat of fresh or ripened milk or cream into a mass, which also contains a small portion of the other milk constituents, with or without salt or added coloring, and contains not less than 80% milk fat.

Butter is produced by churning cream until the fats separate from the liquid (buttermilk) and the butter is in a semi-solid state. It is believed that the Nomads first discovered butter-making by mistake. They are said to have collected milk from cattle and goats, separated the cream from the milk, and continuously mixed the cream until it turned into butter.

Butter is graded on four primary factors:  Flavor, Body, Color and Salt.  These four factors produce the final grade of the butter.

Flavor Intensity

Flavor is the preliminary quality factor in grading butter and is determined organoleptically by taste and smell.

Body Characteristics

Body refers to the textural characteristics of butter with regard to spreadability and mouthfeel. Butter should have an attractive appearance, show no free moisture droplets, cut clean when sliced and be easily spreadable.

Color

Color refers to the evenness of color and shades of yellow of the butter. The natural color varies according to seasonal and regional conditions.  Color is considered defective when it is uneven (mottled or streaked) or lacks uniformity within the same churning or package.

Salt

Salt is discerned from the degree of salt taste and whether it is completely dissolved. A range in the salt content or salty taste is permitted without considering this to be a defect.

The presence of a Wisconsin grade mark on butter allows the buyer and seller of that butter to have a mutual understanding of its properties and thereby avoid conflict.  The Wisconsin grade mark means that the butter has been inspected and graded by an experienced and highly trained grader licensed by the Wisconsin Department of Agriculture, Trade and Consumer Protection. To acquire a license, an individual must take and pass an exam administered by the Department that measures their knowledge about butter and its attributes.  And it means the butter was produced in a licensed plant, under sanitary conditions. It is your guarantee of consistent and dependable quality.

Butter processed and sold in Wisconsin must be placed in one of several grading categories:

• Wisconsin grade AA
  
• Wisconsin grade A
  
• Wisconsin grade B
  
• Undergrade
  

Wisconsin Grade AA butter has a smooth, creamy texture and is easy to spread. It contains a light, fresh flavor and a small amount of salt. Grade AA butter is made from sweet cream and is available at most grocery stores and supermarkets.

Wisconsin Grade A butter is made from fresh cream, has a slightly stronger flavor and possesses a fairly smooth texture. Grade A butter is also widely available.

Wisconsin Grade B butter can be used by consumers for table use. It is usually made from sour cream and is coarse in texture.

Butter that fails to meet the requirements for Wisconsin Grade B is identified as Wisconsin Undergrade Butter.

Butter is first evaluated on its flavor characteristics to determine its preliminary classification as AA, A, B or Undergrade.  It is evaluated using a scale of Slight, Definite or Pronouned intensity. 

Flavor Characteristics

Some of the flavor characteristics that are looked for in this evaluation include:

Once the preliminary classification is established, the butter is evaluated based on body, color, and salt characteristics. Depending on the intensity of any of the characteristics listed in the table below, the butter is disrated, or downgraded, based on points.​

Body, Color and Salt Characteristics

Using the same evaluation scale, the cheese's body, color and salt content are evaluated.  Some of the specific things that are looked for in each characteristic are:

The final grade is assigned once the total disrating points are calculated.  The butter is potentially downgraded depending on certain pre-established thresholds.

All butter sold in Wisconsin must contain a label bearing a statement of the grade determined using the process outlined above. The grade statement must include reference to Wisconsin and the grade with some acceptable variations including abbreviation of Wisconsin to Wis. and the grade letter can precede the word “grade”.  The following are both considered acceptable labeling statements: Wisconsin Grade AA or Wis. AA Grade. The statement must be in a font size that is no smaller than 12-point type on a strongly contrasting background and should prominently appear on the part or panel of the label that is presented or displayed under customary conditions of purchase.

For grades AA or A, a uniform grade insignia may be used on the package consisting of the grade statement enclosed by an outline map of Wisconsin. The lines forming the map cannot be less than 3 points in width and no other writing can appear within the outline map.

​The only exception to these labeling requirements is if the butter already bears the grade U.S. Grade AA, U.S. Grade A or U.S. Grade B. In that case, no other labeling is required.​