A close-up of homogeneous emulsion molecules.



What is Homogenization?

Homogenization in milk is a process that breaks the fat globules into much smaller and uniform size particles that resist joining together and rising, thus keeping liquid milk uniform. This process of making uniform sized particles is the foundation of a homogenization system.


Homogenization has been successfully used for years in the creamery manufacture. Homogenization was first developed in France around 1900 to prevent the milk and cream from separating into two layers. Fat globules clump together and rise to form the cream layer, leaving a fat-depleted phase below.


Recently, the homogenization of ingredients for bread has gained momentum in the baking industry. The process is to obtain a more uniform mixture of the dough ingredients containing shortening or oil. If the shortening used is in a liquid state, the mixture produced by the homogenizer can be referred to as an emulsion. When an emulsion was used in a dough, greater volume can be developed in the same period of time, bread has better symmetry, better color of crust, better grain and texture and the emulsion loaf usually carries more moisture.


The current homogenizing processes can be divided into three major categories:

  1. Ultrasonic homogenizing
  2. Pressure homogenizing
  3. Mechanical homogenizing

In the baking industry, the pressure homogenizing process is commonly used. To make an emulsion, a solution needs to be made up first. Water, together with milk powder and sugar, are put into the agitating tank of the homogenizer and agitated until a homogenous mixture is formed. After the temperature increases to around 38 ℃ (100 ℉), shortening is added and agitated until it melts. The mixture is then run through the homogenizer at a pressure of 1800-2000 pounds per square inch, and the emulsion is ready for use.