Before Churning

• The process of churning begins with whole milk. When left to settle, raw whole milk separates naturally into cream and skim. A dairy may then remove the fatty cream from the top to use in making butter.
  
  

Forming Butter Grains

• Cream is an emulsion of fat particles floating in liquid. Each fat globule is surrounded by a membrane that prevents it from joining with other fat particles. Churning disturbs the cream and breaks up the lipoprotein membranes surrounding each globule of fat. This allows the fat to clump together, forming small butter grains.
  
  

Fat Network

• As the process continues, butter grains come into contact and grow larger. Vigorous churning incorporates air into the liquid, creating a foam. The liquid part of the cream is also trapped by the growing network of fat.
  
  

Buttermilk

• When churning is near complete, the fat globules clump together and pop the air bubbles between them. Liquid buttermilk runs out and may be drained away from the butter.
  
  

Finishing Butter

• After churning, more gentle stirring causes the fats to coalesce. This kneading also gives butter a smooth texture by dispersing any remaining water droplets evenly. Finally, the churning process produces a solid mass of fat.