Every step in the production process plays a vital role in determining the quality of the final baked goods. To achieve exceptional mixing results, it is essential to maintain consistency in the process, ensuring that each batch meets the same high standards.
Batch mixing goes hand-in-hand with product diversity and varying quantities. It ensures the uniform distribution of the ingredients in the mix, with strict recipe control, yet great flexibility for diversity in formulations. The result is consistent product quality, for each batch. When versatility is a top priority for mixing different kinds of dough, a mixer that supports interchangeable tools is the answer, with a quick changeover system.
For mixing tools, there is no ‘one type fits all’ solution. Choosing the suitable mixing tools depends largely on the types of dough to be processed. However, some tools can be used for several jobs. For example, spiral mixing tools are ideal for stretching dough and handling both low- and high-hydration doughs, meaning that they can be used for products such as baguettes, bagels, and various types of bread. A whisk is the go-to tool for aeration, creaming, and creating light, airy textures, making it perfect for preparing whipped cream, mousses, or creams. Meanwhile, a beater is designed for compressing dough while preserving inclusions, making it particularly useful for working with doughs that lack structure. For rich, low-hydration doughs such as tart doughs, rolled doughs, or frozen doughs, a double-tool is the optimum choice for best mixing results.
For industrial-scale operations, VMI, a technology brand of Coperion, developed SPI spiral mixers. These mixers can process batch sizes ranging from 220 liters (120 kg of dough) to 700 liters (550 kg of dough) as standalone equipment and up to 1,000 liters when integrated into an automated system. SPI spiral mixers can use a comprehensive array of tools, including spirals, paddles, whisks and cutters, making them suitable for all types of dough. In addition, the SPI DAVI model comes with a double-tool design.
Different modes, consistent results
The choice of mixing tool and technology is primarily driven by the recipe and the final product. The mixer’s design ensures that the bowl/tool ratio, among other features, is adapted to meet volume requirements while ensuring consistent mixing results.
Different products have their own recipe-specific mixing requirements, at any volume. SPI mixers work with user-friendly SCADA systems: “Our intuitive operator interfaces enable the control of operations and parameters on the production line, including recipe programming, and data analysis,” explains Melanie Gay, Marketing Manager, VMI.
SPI mixers offer customizable settings for various parameters, including the number of phases, mixing time, mixing speed, duration of each phase, bowl rotation direction, and temperature control. When saving a new recipe, you can also preset how the ingredients will be added. They can be brought out of the mixer through the hatch on the cover or by raising the mixer’s head. The level of automation can be chosen as needed: “Manual mode can be used for some productions, while pre-created recipes can be used for others. Operators can easily select and launch recipes, and receive visual or sound alerts for actions, such as cycle completion or ingredient addition,” she explains. For pre-configured recipes, while on automatic mode, the operator simply selects the recipe and starts the process.
SPI mixers
There are three ranges of mixers in this family: SPI AV, SPI AVI and SPI DAVI – each designed for specific needs. All SPI mixers can be equipped with HMI or digital timers and offer a wide range of tools.
+ The SPI AV uses a collar system for bowl locking and comes in two versions:
• Access Version, featuring two digital timers for manual operation
• Touch Version, with an intuitive HMI for process control and recipe storage
+ The SPI AVI uses a clamp-locking system that lifts the bowl off the floor, for more consistent kneading and improved dough quality, especially for bigger batches, above 630 l/400 kg.
+ The SPI DAVI features a clamp locking system and a double-tool design, making it ideal for working with rich, stiff, or low-hydration doughs such as pie dough, quiches, and frozen doughs.
In manual mode, settings should be adjusted before each mixing phase to configure the desired parameters such as mixing time, speed, and bowl rotation direction. For example, “When preparing baguettes, the pre-mixing phase might require 105 rpm for 3 minutes, followed by 120 rpm for 1 minute. Without a recipe mode, you must return to the mixer after 3 minutes to adjust the speed and restart the process,” Gay illustrates. In automated mode, these adjustments occur automatically with pre-saved recipes.
For temperature control, SPI mixers use a sensor to monitor the temperature of the dough, which can be tracked on the HMI. There are several options available related to the measurements monitored: a target temperature can be set for each phase, with a choice to stop mixing when it is reached, for instance.
Different bowls, different process steps
Mixers also offer choices related to the bowls they use, whether fixed or removable. This primarily depends on the batch size and production scale, VMI observes: fixed bowls must be emptied manually, a method that works well for craft bakeries where smaller batches are manageable. Removable bowls are preferred in industrial settings, for efficiency and scalability: “These bowls simplify ingredient introduction and, more importantly, make it easier to empty large quantities of dough,” Gay highlights. They can be combined with elevators to transfer the dough directly into hoppers or onto conveyors, to streamline the production process.
Each type comes with its cleaning needs and methods, which are also influenced by the type of dough processed (the higher the water content, the stickier the dough, the more challenging the cleaning process). In general, the presence of a drain plug makes cleaning easier, for both fixed and removable bowls. The latter can also be moved to be cleaned away from the production area. VMI notes: “For industrial setups, we even provide Clean-In-Place (CIP) stations, which are typically integrated into automated batch mixing systems. These stations lift the removable bowl and clean it using high-pressure water, offering a highly efficient and hygienic solution that requires no human intervention.”
Instead of a ‘one type fits most’ approach, the strategy for selecting batch mixing technology for each operation is tailored to create ‘a custom solution that fits all’ product and production requirements. The resulting dough, and final product will be consistent with every batch, shift, or season.
The second part of this article will delve into spiral mixing technology from Diosna. Read it in the upcoming issue of Baking+Biscuit International.
