Vertical dough mixer consists of three parts, control cabinet, stirring paddle and dough tub. The control cabinet adopt with button touch control, which control the rise and fall of the dough tub and the speed of agitator. Two stirring paddle are designed with two optional speed good for quality dough mixing. High speed for hard biscuit dough about 25rpm.Low speed for soft biscuit dough about 16rpm.The dough tub equipped with rollers is more suitable for hard dough which needs to be fermented and easy for workers to push into the fermentation. Slots under the dough tub are designed to automatic dough pouring into the next manufacturing process(hard dough cutting machine).

To get good quality dough the hard dough is usually mixed on vertical dough mixer. Two or three paddle machines are used with high mixing speed, 25rpm. The high but gentle mixing action incorporates the ingredients well without undue work input at the sponge stage.
The yeast should be dispersed in water before feeding to the mixing tub. The dough is mixed to a temperature of 30~35℃, which is the optimum temperature for the action of the yeast. The sponge is fermented for 12hours at a temperature depends on the biscuit master. During this time the pH value will change from about 5.5 to 4.0 and the temperature of the dough will increase.
After the fermentation of the dough, the dough tub is taken back to the mixing room. The additional ingredients for the dough are added, including the sodium bicarbonate. Gentle, slow speed mixing is required until homogeneous dough is made. Over-mixing will reduce the spring and give a hard, tough product. After mixing, the dough is returned to the fermentation room for up to 4 hours. With the addition of soda, a large change in the pH occurs and the dough will reach a pH of over 7.0.