Following the division of the dough pieces and rounding, these dough balls must undergo a short resting period to allow them to be properly shaped before the final fermentation and baking.
Resting the dough after rounding, and before shaping, is a common practice in bakery operations. The goal of this step is to modify the rheology of the dough to facilitate shaping. After the processes of dividing and rounding, the dough has been subjected to stress, reducing its extensibility. During the resting period, the dough relaxes and increases extensibility, reducing its toughness. These changes are influenced not only by time but also by the fermentation that occurs, which helps increase the dough’s strength and reduce stickiness. These rests are crucial in processes where no oxidizing agents are incorporated. In such cases, as seen in older treatises, resting times of over 20-30 minutes are recommended. However, with the incorporation of oxidizing agents, resting times can be reduced to just a few minutes, as is the case in most modern processes.
The resting typically takes place in special equipment where each dough piece is placed in suitable compartments, usually made of fabric, and moves both horizontally and vertically. The size of the device and the speed at which the compartments or bags containing the dough pieces move determine the resting time. During this resting period, as in all fermentation processes, it is important to control the temperature and ambient humidity. Normally, resting chambers allow for temperature control, but not all of them allow humidity control. In such cases, it is advisable that the ambient humidity remains constant, and it is less problematic in short rests than in long ones. Higher temperature (and more yeast) leads to faster fermentation, allowing for shorter resting periods. However, there is also a higher risk of variations if the resting times change. Typically, these rests are carried out at a slightly lower temperature than the final fermentation temperature. The humidity should be around 75%, to maintain the moisture of the dough pieces. But this humidity can also be used to modify the texture of the dough’s surface. For instance, if you want to dry the dough slightly, you can opt for slightly lower humidity levels, and if you want it to be stickier, you can increase the humidity.
The resting times and temperatures can affect the final crumb structure or the presence of holes, and there are no fixed rules. They should be chosen based on experience and after conducting various tests. In general, longer rests can result in a coarser crumb structure, typical of baguettes but undesirable in sandwich loaves.
Due to the reduction in resting times allowed using dough improvers, some industrial facilities have opted to rest the dough directly on conveyor belts. Since this method is very fast, the temperature and humidity conditions have less influence, although efforts should be made to keep them constant. However, this approach saves time and machinery costs and possibly cleaning costs, but it increases the space requirements since some resting time (even just a few minutes) is still necessary and slowing down the conveyor belt speed (which would reduce space needs) can create a bottleneck in the production line.
After resting, the dough pieces need to take on their final shape. Once shaped, the pieces undergo minimal changes during the fermentation and baking processes, at least in terms of their form. However, their volume and internal structure will change as a result of baking. Shaping the dough pieces must occur before the final fermentation. In this process, the gluten network is reorganized, the dough degasses, and the final shape is achieved.
There are numerous bread shapes, and therefore, there are various shaping equipment. Some breads are round, like “hogazas” or hamburger buns, and in these cases, it may not be necessary to significantly modify the shape of the dough balls obtained after rounding, or simply flatten them slightly, either by hand or by passing them through rollers or a flattening plate. When softer and stickier dough, it is common to roll out the dough and cut it into squares, rectangles, or other shapes without significantly altering the dough. However, most commonly, the dough is given a cylindrical shape. This cylinder will be thicker for pan breads, thinner for baguettes, and somewhat thinner for other varieties. This shaping process consists of three phases: initial rolling of the dough, followed by rolling it into a cylinder, and then stretching the formed cylinder. The adjustments made in each of these phases determine not only the external appearance of the bread but also its crumb structure.
The key factor in shaping operations is the dough’s rheology and stickiness. The dough should not be excessively tough and should be extensible; otherwise, it can complicate the initial rolling, possibly causing it to tear. However, dough that is too soft can also be problematic, as it stretches more, affecting the uniformity of the pieces and, in extreme cases, may even tear. Dough stickiness is crucial because excessive stickiness promotes dough tearing and can soil the rollers and machinery, affecting subsequent operations. On the other hand, dough that is too dry on the surface may “slip” and not go through one of the shaping phases. To control the dough’s rheology, aside from the formulation and flour type, resting (fermentation) before shaping plays an essential role. To adjust stickiness, it’s important to regulate humidity during this phase. Humidity should not be too high (resulting in stickier dough) or too low (resulting in drier dough).
Dough pieces (usually in the form of balls) are rolled out by passing them between rollers (or between a roller and a conveyor tray). In industrial lines, progressive rolling is common, where the dough passes through multiple sets of rollers, each set progressively tighter, until the desired dough thickness is achieved. In more artisanal processes or smaller bakeries, it is more common to use a single set of rollers for rolling, taking place in a single phase. Progressive rolling allows for thinner dough because dough cannot withstand a drastic reduction in thickness without tearing. However, with the progressive system, the dough can relax between sets of rollers, enabling further thinning.
It is crucial to keep the rollers clean, free of dry dough residue, to ensure proper and consistent operation. To prevent excessive stickiness, metal rollers are typically coated with a layer of Teflon. Regular oiling is also common to improve dough flow through the rollers.
The thinner the rolling, the more degassing occurs, resulting in a finer and more uniform crumb structure. This is crucial in bread such as sandwich loaves, where a fine crumb structure is highly valued. In baguettes and other types of bread, this factor may not be as critical. However, it should be noted that the final gas distribution will not be uniform. The dough retains more gas in the central part and less at the ends, as well as more gas internally than externally. These differences can translate into variations in the crumb structure in different areas of the final pieces, especially in sandwich loaves. To minimize these differences, it is recommended to roll the dough as thinly as possible, along with other practices we will address later.
The rolled-out dough sheet must be rolled up into a cylinder. In this operation, the goal is to form a cylinder from the dough without applying excessive pressure. For this purpose, devices are used, typically consisting of metal rods on fabrics or a metal lattice, which fold the leading edge of the dough sheet when it reaches the device, rolling up the entire dough as it advances, forming a cylinder.
Once the cylinder is formed, it is compressed by passing it between two bands of fabric or rubber. This operation expels the trapped air between the folds, achieves the final length of the piece, and closes the folds of the previously formed cylinder. The devices for performing this operation typically exert more pressure in the central part of the cylinder so that the gas is gradually pushed toward the ends, like the hand shaping technique. In the production of sandwich loaves, excessive or insufficient compression can result in issues with the crumb, such as a coarser and irregular crumb structure or the presence of holes. While these defects are less noticeable or less critical in the production of baguettes and other bread types, proper compression remains essential, and equipment and dough rheology must be adjusted to ensure uniform results.
Some equipment allows for stronger compression at the ends, creating a tapered shape. In special cases where stronger than usual compression is required, such as with baguettes to achieve thinner and elongated products, a two-step compression process may be used. After the initial compression, the formed pieces relax to relieve tension before the final compression is applied.
In some bread preparations, alternative shaping processes are used. One common approach involves changing the direction of stretching. The dough pieces can be rotated 90 or 180 degrees between passes through the rollers, equalizing distortions within the dough, resulting in a more consistent final product. Alternatively, the laminated dough can enter the rolling equipment at a 90-degree angle. All these methods aim to achieve greater regularity throughout the final piece.
With the same goal, some manufacturers divide the dough cylinder into four equal pieces and place them in the mold transversely, filling the mold but in the opposite direction compared to when the cylinder is placed longitudinally.
Another variant is creating a braided shape. To achieve this, two dough cylinders are obtained through the previously described operations. These cylinders are usually thinner than those obtained through traditional shaping. The two cylinders are intertwined to form a braid, which is typically placed inside a mold, but it can also go through the process without a mold. This shaping results in a finer and more uniform crumb structure and a smoother texture, but it is more complex and requires special equipment or a significant amount of manual labour.
In the operations of dividing, rounding, and shaping, it is possible to encounter dough that is excessively sticky. While there are some “tricks” to reduce stickiness, they should be minimized as they can negatively impact the final product’s quality. Therefore, it is preferable to control parameters such as flour quality, dough hydration, or temperatures and humidity during fermentation processes, and avoid the practices we will discuss.
One of the most common practices to reduce dough stickiness is dusting with flour. This is common not only in industrial settings but also at home. By incorporating flour onto the dough’s surface, it is absorbed, temporarily drying the surface. This effect is short-lived, and once the flour is absorbed, stickiness may return. Excessive use of flour can result in spots or an unusual color in the final product’s crumb. It can also alter the final product’s hydration and create slight variations in bread characteristics. Therefore, this practice should be minimized and never exceed 1% of flour in the dough. To ensure effective drying, it is advisable to use flour with the lowest possible moisture content. In some cases, such as pizza making, semolina is commonly used instead of flour. Semolina works well to prevent dough from sticking to surfaces and is absorbed more slowly, but it can impart a slightly sandy texture to the final product. This texture is acceptable and even desirable in products like pizza but may appear strange to consumers in other products.
Another technique is air drying. This involves passing a stream of air over the dough, causing it to dry slightly. In some industrial lines, fans are commonly used for this purpose. Surface drying can be achieved at room temperature, but in conditions of high humidity, it may be necessary to heat the air with some form of heating element.
It is also essential to reduce the stickiness of the dough inside molds or on surfaces. To do this, anti-adhesive coatings such as silicone resins that can withstand high baking temperatures are typically used. This coating may wear off over time and with repeated washings and should be checked regularly. To enhance the anti-adhesive effect, it is also common to spray a release oil inside the molds. If these oils are used, care should be taken with cleaning and the potential risk of rancidity over time.
Another critical factor in using molds is the temperature of the mold when the dough is deposited into it. In industrial lines, it is common for molds to reach the area where the dough is placed inside after discharging one loaf, following baking, and thus at high temperatures. This should be avoided as it accelerates the fermentation of the external areas, causing differences in products based on mold temperature and potentially increasing dough stickiness. For this reason, molds are typically cooled before being loaded with dough. Cooling methods vary, similar to bread cooling methods, ranging from rapid cooling with forced air to simply removing the molds after baking and allowing them to cool in storage. However, the temperature of the molds at the time of dough deposition must be controlled to achieve consistent and uniform production. Ideally, the temperature should be similar to the fermentation temperature to be used.
This text has been translated into English with the help of Artificial Intelligence. Any errors are my responsibility.