Butter Churns

Churn is a device for making butter. Traditionally, various types of churns such as Rocker churns, Dash churns, Wooden-barrel churns, Tin churns, Stone-ware churn,and Glass churn jars (as shown in the Fig ) etc., are used for butter making.

 

i. Basic Designs

The basic designs of butter churn may be classified in three groups as follows.

a) Swinging churns: The cream moves backward and forward in a horizontal plane. There are internal diaphragms in the churn to obstruct the flow of cream to some extent and thus to increase the intensity of agitation.

b) Rotating churns: These are either barrel or alfa churns. Modern factory churns (wooden or metal) have been developed from rotating barrel type of churns.

c) Dash churns: In these, the cream-holding vessel is stationary, while the agitator or dasher (plunger, disc or rotating blade) is mobile.

Butter Churns

 ii. Modern Churns

Modern industrial churns are large, barrel-shaped, revolving containers in which the cream is agitated until the microscopic fat globules clump together to form butter and separate from buttermilk. The liquid buttermilk is drained, and the butter washed with potable cold water. Following types of modern butter churns have been developed over the years through the modification of the basic designs.Combined-churn and butter worker: Early factory churns only churned the cream into butter, the working was done separately on circular/rectangular worker tables. The combined-churn-and-butter-worker was developed so that butter could be worked within the churn itself; the workers were installed on a trolley, which was pushed into the churn from either one of its ends or sides.

Roller-less (roll-less) churn: In these wooden churns, the working is effected without the aid of rollers, which were considered to be unsanitary. Vanes were fixed to vane churns, to help in the churning and the working of butter.Modern metal churns. These have been developed mainly in Denmark and the USA. The usual shapes are cylindrical, cubical or conical. The metal used for the product contact surface is either stainless steel or aluminium alloy. The internal shape is so designed that the working is effected by the rolling action of butter.

Metal churns offer following advantages:

 Ease of cleaning with alkali detergents
 Sterilization with steam without damaging the churn body
 Accuracy of moisture and salt control
 Intermittent use without deterioration in quality
 Better sanitary aspects

The major disadvantage of the metal churn is that it is difficult to control the temperature because of its low heat insulating capacity. However, it can be obviated by installation of the butter churn in an air-conditioned room or making provision for chilled water spray during churning and working.