In baking, there are certain operations between kneading and the final fermentation that are often overlooked and have been relatively underexplored by scientists. However, these operations can significantly impact the quality and consistency of the final product. We will address these operations in two separate entries. This first one is dedicated to division and rounding, while the subsequent entry will cover resting and shaping of the dough.

Division

After kneading, the dough can undergo a bulk fermentation or not. Typically, dough with higher hydration and softer consistency tends to undergo this type of fermentation more. In such cases, the goal is to modify the rheology of the dough and reduce its stickiness, while also achieving other effects associated with fermentation. These effects depend on factors such as yeast dosage, temperature, and time, as in all fermentation processes. Therefore, it is essential to regulate these parameters. A lower yeast content, longer time, and lower temperature will enhance the action of lactic acid bacteria, resulting in the production of lactic acid and, to a lesser extent, acetic acid. This reduces the pH of the dough, modifying the gluten network to make it slightly tougher and less extensible. Conversely, a higher yeast content and shorter fermentation times minimize the action of lactic acid bacteria but generate more gas. While this gas may not significantly impact the final product’s volume, it does affect the internal structure of the crumb. Doughs with higher hydration exhibit an alveolar structure that, when expanded by the gas, tends to form larger alveoli through the coalescence of some of the bubbles. This effect is less prominent in doughs with lower hydration since the alveoli have less mobility and face more difficulties merging. As a result, highly hydrated doughs, which undergo bulk fermentation, tend to produce bread with large, irregular alveoli compared to other types of dough.

After this resting period or immediately after kneading, the dough needs to be divided into pieces of uniform weight. Achieving the desired weight for these pieces is crucial because the final product’s weight depends on it. Providing pieces with less weight, and consequently a lower final weight, may disappoint consumers, while exceeding the defined weight could result in significant economic loss. In any case, the weight of the pieces should be consistent to ensure consumers receive a product with very similar final weights. Small bakeries can do this process manually, using visual estimation followed by weighing and adjusting the weight by adding or removing a portion of the dough. However, in large bakeries and industrial settings, this process needs to be mechanized for time and cost savings.

Regrettably, most dough dividers are volumetric dividers, meaning they do not work based on weight. They cut pieces of consistent volume. The dough falls by its weight or is pushed by the system into compartments with predetermined volumes, where it is cut. If the dough’s density remains constant, the weight of the pieces should be regular.

However, numerous factors can modify the weight of the pieces. For instance, if the dough ferments, generating gas and reducing its density, this will affect the weight of the pieces as the process progresses. Obviously, these changes are minimized if the yeast quantity or the dough temperature is lower and are accentuated under different conditions. In any case, reducing the rest time between kneading and division, and dividing the entire batch from the same kneading with a narrow time margin, is advisable.

Another factor that can affect the process is the rheology of the dough. If the dough must flow towards the lower part of the hopper, it will not flow the same way if it is sticky as compared to a more tenacious and drier dough. This difference can generate variations in the weight of the final pieces. The dough’s weight should also be considered. When the hopper is full, there is a significant force pushing the lower part into the division devices. But as the hopper empties, this force decreases, which can lead to variations in the weight of the pieces. Typically, different kneaded doughs are added to the hopper gradually to maintain a minimum weight.

Any dough remnants that couldn’t be divided and remain at the bottom of the hopper should not be divided using these machines afterward. These remnants will have changed their characteristics, such as density and rheology, and it’s better to reintroduce them into a new kneading cycle to minimize these differences among the rest of the dough.

To address the issues related to variations in dough density, some manufacturers have chosen to degas the dough before division to standardize its density to some extent. While this method can improve the consistency in the weight of the pieces, it can also affect the dough and its internal structure, potentially modifying the bread crumb structure. Therefore, it must be carefully studied and evaluated.

Since this method is not perfect, it is essential to check its reliability. It is advisable to have an operator randomly weigh pieces to ensure their weight is correct. Typically, these weighed pieces are slightly heavier than the target weight for the final pieces, accounting for potential weight loss due to evaporation. However, these differences can vary based on each production line and factory. If the pieces have significantly different weights, the divider’s settings need to be adjusted. Today, for large production lines, there are automated weighing systems that can monitor the weight of all pieces and even interact with the divider to correct errors or deviations.

Another aspect to consider during the division process is its impact on the rheology of the dough. Mechanical work is always applied to the dough during this process, and this affects its characteristics. For instance, dividers that force the dough’s passage through mechanisms like augers may alter the dough’s rheology more than those where the dough flows naturally due to gravity. In the former case, if the flour quality is not ideal, problems similar to over-kneading (excessive work on the gluten network) may occur. These issues can be minimized with flours that are more tolerant to excessive kneading. You can analyse these characteristics through farinographic analysis.

There are other types of dividers known as hydraulic dividers, which are quite common in small bakeries. These dividers are based on a system of blades that cut the dough into equal parts. For example, in such a system, if a 2000 g piece of dough is divided into 20 equal parts, the final pieces will weigh 100 g each. To achieve this, the dough is pressed in advance to distribute it evenly across the surface. After this operation, blades are raised or lowered, cutting the entire surface into pieces of equal area. If the height and area of the dough are the same, its volume will also be similar, and its weight can be predicted.

Rounding

After division, the pieces are typically rounded. There are several theories to justify rounding, but the most significant aspect, in my opinion, is to ensure consistency in the pieces and the baking process. After division, the pieces have an irregular shape, with some areas stickier than others, and without rounding, this irregularity could lead to variations in the final product. Rounding also smoothes the surface, reduces stickiness, and somewhat closes any pores that may exist. Some experts claim that this improves gas retention and modifies gluten alignment. I can’t confirm this as further modifications in dough structure occur during subsequent resting and shaping. Nevertheless, rounding is a practice conducted worldwide.

There are various types of rounding machines, but the primary objective is to quickly give the dough a regular ball shape and adapt to the production line. The most common rounding machines include cone-shaped, inverted cone-shaped, double-belt, and belt and tile rounders. In cone and inverted cone rounders, the pieces are placed between a rough surface (which retains the dough) and a mobile one. In cone rounders, they move within a sort of chute around a central cone that rotates. In inverted cone rounders, the chute is located inside a rotating cone. This chute can also be positioned around a cylinder. The dough moves faster through the narrower parts in conical rounders, while there are fewer differences in cylindrical rounders.

Cone and cylindrical rounders

Another option is to use a mechanism with indentations placed over the pieces of dough so that each indentation contains a piece of dough. Once lowered, this mechanism starts rotating, causing the pieces to rotate and round as they hit the walls of each indentation. This device is more challenging to adjust for different-sized pieces as the head needs to be replaced and is often used in small bakeries, mainly for pastry products.

The dough can also be rounded as it moves between two conveyor belts or bands arranged in a V or U shape. While one belt moves at a faster speed, the other moves more slowly, creating friction that slows down the dough and forces it to rotate and round. The friction between the dough and the belt is crucial for achieving this rounding effect.

One final option is to round the dough as it moves horizontally on a conveyor belt. For this, a piece like an elongated tile is positioned at an angle to the direction of belt movement. When the piece comes into contact with the tile’s concave surface, it is forced to rotate and round.

Double-belt and belt and tile rounders

When selecting a rounding system, you need to consider various factors such as available space, the speed of each system to ensure it does not become a bottleneck, integration into automated processing systems, cleanliness and hygiene aspects, and more.

Exceptions

Lastly, it is important to note that some doughs do not undergo division and rounding in the manner explained. These are high-hydration, very sticky, and excessively soft doughs that cannot be processed through these machines. Instead, these doughs are typically laminated to ensure they are uniformly distributed on a conveyor belt. Subsequently, the dough is cut into strips using blades or specialized devices. These strips are then cut into square or rectangular shapes, although inclined cuts are also possible. This is the typical method used to create ciabatta bread, for example. This technology can also be applied to the production of high-hydration baguettes. The pieces formed in this way are not rounded and go directly to the final fermentation and subsequent baking. Like other dividers, this process involves volumetric division, so it is essential to control the dough’s density and the weight of the pieces to address any irregularities.