Mastering Biscuit Production: The Science of Dough Mixing and Equipment Optimization

A biscuit production line is designed for the stable, mass production of biscuits—a globally vital convenience food. A successful line is defined not just by output, but by its ability to consistently produce biscuits that meet rigorous standards: instant consumption convenience, extended shelf life (typically six to twelve months), and nutritional energy value.

While the recipe is foundational, the final product quality is heavily dictated by equipment precision and the synchronization of the production line. A standard industrial process follows these critical stages: Mixing → Fermentation →  Dough Standing →  Forming →  Baking →  Cooling →  Packing.

Among these, mixing is the cornerstone. It controls the rheological properties of the dough, which is the prerequisite for proper shaping and baking.

The Science of Dough Mixing

Mixing is more than simple blending; it is a complex physicochemical process. During this stage, three critical changes occur:

1. Homogenization: All raw materials are integrated into a consistent mass.

2. Emulsification: Fat and water within the dough are emulsified to ensure texture stability.

3. Gluten Development: Proteins in the flour hydrate to form gluten networks (crucial for hard dough) or are coated with fat to inhibit gluten (crucial for soft dough).

Dough Classifications and Mixing Techniques

Different biscuit textures require distinct mixing strategies.

1. Hard Doughs (Crackers & Semi-Sweet Biscuits)

Hard doughs generally contain higher water content with lower fat and sugar ratios. The primary goal during mixing is the development of a strong gluten network, which provides the open, flaky texture required during baking. As mixing imparts mechanical work, the dough temperature naturally rises.

• Process: For most hard doughs, all ingredients are fed into the mixer simultaneously. After mixing, the dough—particularly for crackers—is transferred to a proofing room for fermentation.

• Soda Crackers: These often require a two-step mixing process where ingredients are added in stages to control fermentation and texture.

2. Soft Doughs (Short Doughs)

Unlike hard doughs, gluten development must be minimized in soft doughs to ensure a tender, crumbly texture.

• Process: This typically utilizes a "Creaming Method."

  • Stage 1: "Cream up" by mixing all ingredients (fat, sugar, liquids) except flour into a soft, aerated mass.

  • Stage 2: Add the flour and mix briefly. It is critical to mix for the shortest time possible to prevent the proteins from forming a tough gluten network.

3. Cookie Doughs

Cookie dough is a variation of soft dough, characterized by high fat and sugar content.

• Process: Similar to soft doughs, a two-stage mixing process is used to incorporate flour last.

• Temperature Control: To prevent the fat from melting prematurely and altering the dough structure, mixing temperatures are typically maintained below 20°C.

Selecting the Right Mixer

Golden Bake offers specialized mixing solutions tailored to specific dough characteristics.

Vertical Mixers

Vertical mixers are the industry standard for fermented doughs. Because fermentation requires the dough to rest in tubs rather than moving immediately to the forming line, vertical mixers are designed for logistical efficiency.

• Mechanism: The mixer spindles are positioned vertically. These units utilize movable dough tubs, allowing ingredients to be fed manually or via overhead hoppers. Once mixed, the tub can be easily transported to the fermentation room.

• Golden Bake 1100 Vertical Dough Mixer: This model is engineered for versatility. It features three stirring paddles and offers two adjustable speeds to optimize dough quality:

  • High Speed (~23 RPM): Ideal for developing gluten in hard biscuit dough.

  • Low Speed (~16 RPM): Optimized for gentle mixing of soft biscuit dough.

Horizontal Mixers

Horizontal mixers are highly versatile and suitable for snack crackers, semi-sweet doughs, and soft (cookie) doughs. They are designed for high-capacity, automated lines.

• Mechanism: Ingredients are weighed by the raw material system and fed directly into the bowl. The mixing bowls are stainless steel and equipped with a water jacket, allowing for the circulation of hot or cold water to precisely control dough temperature.

• Golden Bake 850 Two-Arm Horizontal Mixer: This machine features two agitator arms that rotate towards each other.

  • Efficiency: The dual-arm action causes materials to intermingle and overlap, offering faster and more uniform mixing compared to single-arm models.

  • Gluten Management: The rotating arms efficiently stretch and tear the gluten network. This mechanical efficiency is so effective that it can significantly reduce, or even eliminate, the need for chemical dough improvers, resulting in a cleaner label and lower production costs.