Small biscuit production line

Introduction to Small Biscuit Production Line:

The DTS225 roller-cutting automatic biscuit production line is developed by our company based on the absorption of Japanese technology. The equipment features innovative design, compact structure, and high automation. It completes the entire process automatically from feeding, rolling, forming, waste recycling, drying, oil spraying, to cooling. Our company provides users with hundreds of molds and dozens of process recipes. By changing molds and process recipes, various high-end biscuits popular in the market can be produced, such as cream biscuits, sandwich biscuits, ultra-thin biscuits, soda biscuits, animal-shaped biscuits, multivitamin biscuits, vegetable biscuits, etc.

1. The machine consists of:

Dough mixer — Forming main unit — Oven — Oil sprayer — Cooling conveyor.

2. The machine's process flow:

Raw material pretreatment — Dough mixing — Rolling dough sheet — Pressing into dough pieces — Baking — Oil spraying — Cooling — Packaging.

3. Related knowledge:

The main ingredient of biscuits is flour, along with sugar, starch, oil, dairy products, eggs, flavorings, leavening agents, and other additives. These raw materials and additives are mixed into dough using a dough mixer, then rolled into sheets by a rolling machine, pressed into biscuit blanks by a molding machine, baked in an oven, and after cooling, become crispy and delicious biscuits. Sweet biscuits can be divided into two major categories: hard biscuits and short biscuits. Whether hard or short, although their formulas, ingredient addition sequences, and operating methods differ, the basic process flow is similar.

(1) Pretreatment of raw materials

1. Pretreatment of flour:

For producing hard biscuits, it is advisable to use flour with a wet gluten content of 24-36%; for producing short biscuits, flour with a wet gluten content of 24-30% is suitable.

Currently, it must be sifted before use. The purpose of sifting is not only to break the flour into fine particles and remove impurities but also to incorporate a certain amount of air into the flour, which facilitates yeast proliferation during dough fermentation and results in crisper biscuits. A magnet should be added to the sifting device to remove magnetic impurities. The humidity of the flour should be adjusted according to the season.

2. Pretreatment of sugars:

Granulated sugar is generally ground into powdered sugar or dissolved into syrup for use.

To remove impurities and ensure fineness, the ground powdered sugar should be sifted, typically using a 100-mesh/25.4mm sieve. If the powdered sugar is ground in the workshop, it will have a higher temperature after grinding and should be cooled before use to avoid affecting the dough temperature.

To dissolve granulated sugar into syrup, the amount of water added is generally 30-40% of the sugar weight. During heating and dissolving, control the temperature and stir frequently to prevent burning and ensure the sugar is fully dissolved. After boiling and dissolving, filter it, then cool before use.

3. Pretreatment of fats and oils:

Common liquid vegetable oils, lard, etc., can be used directly. Fats such as butter, margarine, hydrogenated oil, and coconut oil have higher hardness at low temperatures and can be softened by heating over low heat or stirring with a mixer before use. This speeds up dough mixing and makes the dough more uniform.

When heating fats to soften them, control the heat carefully and avoid complete melting, as this would destroy their emulsion structure, reduce product quality, and cause biscuits to 'leak oil.' Whether cooling is needed after heating and softening depends on the dough temperature.

4. Pretreatment of dairy and egg products:

When using fresh eggs, they are inspected, washed, sanitized, and dried. When breaking eggs, care must be taken to remove bad eggs and eggshells. When using frozen eggs, the frozen egg container should be placed on a water tank to thaw the eggs before use. Milk should be filtered. Milk powder and egg powder should be stirred evenly in oil or water before use.

5. Pretreatment of leavening agents and salt:

Leavening agents and salt must be evenly mixed with flour. In biscuit production, water-soluble raw materials and auxiliary materials such as baking soda, ammonium bicarbonate, and salt should be sieved first before dissolving in water. If there are hard lumps, they should be crushed and sieved to form small particles, then dissolved in cold water. Do not dissolve them in hot water, as the chemical leavening agents may decompose partially or mostly under heat, releasing carbon dioxide gas and reducing the leavening effect.

(2) Dough preparation:

The preparation of dough is a critical process in biscuit production. Whether the dough is properly mixed not only affects the normal operation of machinery but also serves as the dividing line between the quality of hard and soft biscuits. The production processes for soft and hard biscuits differ, and the methods of dough preparation also vary significantly. The short dough for soft biscuits is prepared using the cold dough method, while the hard dough for hard biscuits is prepared using the hot dough method.

1. Hot dough method:

The dough temperature is 38-40°C. Generally, first mix oil, sugar, milk, eggs, and other auxiliary ingredients with hot water or hot syrup in a mixer until evenly combined, then add flour to form the dough. If using a dough conditioner, it should be added when the dough is initially formed (about 10 minutes after mixing). Then, during the mixing process, add leavening agents and flavoring in sequence. Continue mixing for about 40 minutes or more to form a tough dough. After the tough dough is fully developed, to reduce the stickiness and elasticity of the bread and maintain dough stability, it must rest for at least 10 minutes before rolling and shaping.

2. Cold powder shortbread method:

First, pour sugar, oil, dairy products, eggs, leavening agents, and an appropriate amount of water into the dough mixer, stirring evenly to form an emulsion. Then, add flour and starch into the dough mixer and mix for about 6-12 minutes. Flavoring should be added in the later stage of emulsion preparation, or it can be added when adding the flour to avoid excessive evaporation of the aroma. In summer, due to higher temperatures, the mixing time can be shortened by 2-3 minutes.

The dough temperature should be controlled at around 22-28°C. For dough with high fat content, the temperature should be controlled at 20-25°C. In summer when temperatures are high, cold water can be used to mix the dough to lower its temperature. If the wet gluten content in the flour exceeds 40%, the fat and flour can be mixed into a shortcrust dough before adding other ingredients, or part of the flour can be replaced with an equal amount of starch in the recipe.

(3) Rolling

The prepared dough should be rolled into a sheet of uniform thickness, even shape, smooth surface, and fine texture to prepare for shaping.

1. Rolling of tough dough

The tough dough should be rested for a period of time before rolling to eliminate the internal tension caused by stretching during mixing, reduce the dough's viscosity and elasticity, and improve the processing properties of the gluten and the quality of the product. The length of the resting time depends on the dough temperature. Generally, if the dough temperature is high, the resting time is short; if the temperature is low, the resting time is long. When the dough temperature reaches 40°C, it should be rested for about 10-20 minutes.

The number of rolling passes for tough dough is generally 9-13 times, with multiple folds and a 90° rotation during rolling. After rolling, the dough is pressed into a sheet of a certain thickness.

2. Rolling of short dough:

Short dough contains a high amount of oil and sugar, making the rolled dough sheet relatively soft and prone to breakage. Therefore, it should not be rolled multiple times, and a 90° turn should be avoided. Generally, unidirectional reciprocating rolling 3-7 times is sufficient. Depending on the specific situation, a single unidirectional rolling may also be used.

Short dough does not need to be rested for a long time before rolling. The thickness of the rolled dough sheet is about 2 cm, which is thicker than that of tough dough. This is because short dough is prone to breakage and is relatively soft, and after passing through the rollers of the forming machine, it can reach the required thickness for forming.

(4) Forming

The dough sheet obtained from the rolling process is made into various shapes of biscuit blanks by the forming machine.

(5) Baking

Crisp biscuits should be baked at a lower temperature for a longer time. After the prepared biscuit dough enters the oven, under the action of high temperature, the moisture inside the biscuit evaporates, the starch is heated and gelatinized, and the leavening agent decomposes, causing the biscuit to expand in volume. The protein denatures and solidifies due to heat, forming a porous and crispy finished biscuit product.

The baking temperature and time vary depending on the type and shape of the biscuit. Generally, the baking temperature is maintained at around 230-270°C and should not exceed 290°C. If the oven temperature is higher, the baking time can be appropriately shortened. Too high or too low an oven temperature will affect the quality of the finished product; too high can easily burn the biscuits, while too low can result in undercooked biscuits with a pale color.

(6) Cooling

For freshly baked cookies, there is a significant temperature difference between the surface layer and the core, with high external temperature and low internal temperature, causing slow heat dissipation. To prevent the cookies from shrinking and cracking, they must be cooled before packaging. In spring, summer, and autumn, natural cooling can be used. To accelerate cooling, fans can be used, but the air velocity must not exceed 2.5 m/s. Excessively fast airflow will cause rapid moisture evaporation, making the cookies prone to cracking. The suitable cooling temperature is 30-40°C, with an indoor relative humidity of 70-80%.

(7) Packaging

Packaging materials: tinplate, cardboard, polyethylene plastic bags, wax paper, etc., 500g.

It should be noted that although biscuits are a shelf-stable food, storage conditions must also be considered. The suitable storage conditions for biscuits are low temperature, dryness, good air circulation, clean air, and a place away from direct sunlight. The warehouse temperature should be around 20°C, and the relative humidity should not exceed 70-75%.

(8) Biscuit images:

Uses and characteristics of the multifunctional biscuit production line

The biscuit production line features innovative design, compact structure, and high automation, enabling fully automatic one-time completion from feeding to rolling, forming, waste recycling, drying, oil spraying, and cooling. By changing molds and process formulas, it can produce various high-end biscuits popular in the market, such as cream biscuits, sandwich biscuits, soda crackers, animal-shaped biscuits, and vegetable biscuits.