What is Continuous Mixing?
Continuous mixing is a process in which dry and liquid ingredients are fed continuously into a mixer via an ingredient automation system. This automated system feeds into the mixer while the dough is mixed without interruption.
This type mixing is a form of mechanical dough development that uses an auger. It takes the place of conventional horizontal and vertical dough mixers.
The continuous mixing technique was developed to meet the needs of batched dough make-up processes. Batched doughs are particularly sensitive to changes in dough consistency and density arising from floor time variations between the mixer and dough divider.1
Continuous mixing creates a very homogeneous dough, based on its continuous ingredient feed process. Unlike batch systems, it prevents the aging of dough when it sits in a dough trough between the mixer and dough divider. Therefore, this eliminates the “beginning of a dough” and the “end of a dough” effect.
The most common form of continuous mixer in use for bread production today is the two-stage mixing system. As with all such systems, it is the integration of an ingredient feed system with a flow-through mixing system.1
A preferment is commonly utilized to increase flavor, texture and aroma for the continuous mix system. A liquid ferment, brew, or liquid sponge is prepared and allowed to ferment under controlled temperature conditions for several hours, and then the fermented mixtures are cooled until ready to be used. The dough is formed by a function of horizontal shaft configuration and shaft speed when moving down the cylinder.
At the discharge of the continuous mixer, fixed-size loaves of dough are cut continuously and moved to the downstream equipment arriving at the precise time. Continuous mixing became popular in recent years, especially in the large commercial bakeries.
The products manufactured by this method have a very fine and tight grain. Single screw extruder and twin screw extruder are the main equipment used in continuous dough mixing systems. Compared with the conventional batch dough mixing systems, continuous dough mixing systems increase dough consistency.
It also simplifies the mixing process, disperses ingredients consistently, allows for better hydration, is safe and sanitary, lowers labor costs and saves space, money and energy. There is no temperature increase during the mixing process, and there is no dough contamination between batches. A variety of products, such as bread, rolls, buns, hard biscuits, cracker, cakes and etc., can be produced by a continuous mixing system.
- Cauvain, Stanley P., and Linda S. Young. “Chapter 4 Mixing and Dough Processing. “Technology of Breadmaking. 2nd ed. New York: Springer, 2007. 106-08.