Smart Recipe Creation for Biscuit Baking Automation

In modern baking lines, consistent quality depends on precise recipe creation and well-controlled process parameters. By defining clear setpoints for temperature, speed, and timing, bakeries can ensure uniform texture, color, and taste across every batch. Below are three optimized biscuit recipes, each designed to highlight how small parameter changes create distinct products.

Recipe 1 – Butter Cookies Butter cookies require gentle baking to preserve their rich flavor and crumbly texture. This recipe uses an oven temperature of 180°C, a conveyor speed of 0.8, and a bake time of 900 seconds to achieve even browning. A fan speed of 1200 RPM ensures uniform heat distribution, while a mixer speed of 70 RPM maintains the ideal dough consistency.

Recipe 2 – Cream Biscuits Cream biscuits need slightly higher heat for a light, crisp finish. The oven is set to 200°C with a faster conveyor speed of 1.0 and a reduced bake time of 840 seconds. Increased airflow at 1400 RPM fan speed supports quick, even baking, and a mixer speed of 75 RPM helps blend cream smoothly into the dough.

Recipe 3 – Digestive Biscuits Digestive biscuits demand longer baking for a firm, wholesome texture. This recipe runs at 190°C, with a conveyor speed of 0.9 and an extended bake time of 960 seconds. A fan speed of 1300 RPM balances heat penetration, while a slightly lower mixer speed of 65 RPM preserves the coarse dough structure.

1. The operator selects a recipe from the HMI (Recipe Selection Screen).

2. The PLC uses a BLKMOV (Block Move) or Multi-MOVE instruction to copy all preset parameters for the selected recipe into active control registers.

Example: If "Butter Cookies" is selected, BLKMOV copies the set of temperature = 180°C, baking time = 15 min, conveyor speed = 0.8 m/s, etc.

3. These active variables are then sent to respective actuators and controllers.

• The oven controller receives the new temperature.

• VFD controlling the conveyor receives the speed.

• Timer logic sets baking duration.

• Cooling fans are set to required RPM.

Recipe Parameters Stored in PLC (Array / Data Block)

In an automated baking system, each biscuit recipe is stored in the PLC as a structured array or data block. This allows quick recipe selection, consistent production, and easy scalability. Each recipe contains the following key parameters, defined in engineering units for clarity and safety:

• Oven Temperature (°C): Controls the baking heat profile to achieve the desired color, texture, and moisture level of the biscuit.

• Conveyor Speed (m/min): Determines the residence time of biscuits inside the oven and directly influences baking uniformity.

• Baking Time (min): Ensures the product remains in the oven for the correct duration to reach proper doneness.

• Cooling Fan Speed (m/min): Regulates post-baking cooling to stabilize biscuit structure and prevent overbaking or cracking.

• Dough Mixer Speed (m/min): Controls dough consistency and ingredient distribution before baking.

Storing these parameters in a PLC data block enables operators to load recipes with a single command, reduces manual errors, and ensures repeatable, high-quality biscuit production across different product variants.

Program language: ST

// Define recipe structure

// Define data blocks

VAR

Active_Recipe : Recipe_Type;    //Active recipe parameters

 Recipe_Select : INT ;      //Recipe number selected from HMI

END_VAR

 //When the operator selects a recipe number between 1 and 3, the system considers the index valid.

IF (Recipe_Select >= 1) AND(Recipe_Select <= 3) THEN

// The selected recipe data structure is copied into the Active_Recipe buffer.This is equivalent to a multi-move or block move (BLKMOV) operation.

COP(RECIPE[Recipe_Select],Active_Recipe,1);

END_IF;

//After loading, individual parameters from Active_Recipe are applied to the machine. This allows the machine to quickly configure itself for different products or batches.

Oven_Setpoint := Active_Recipe.OvenTemp;

Conveyor_SpeedCmd  := Active_Recipe.ConveyorSpeed;

Baking_TimerPreset := Active_Recipe.BakeTime;

Fan_SpeedCmd       := Active_Recipe.FanSpeed;

Mixer_SpeedCmd   := Active_Recipe.MixerSpeed;

List of software used for testing

1. Studio 5000 logix designer V36

2. Factorytalk view Studio

3. Emulator V36

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