A vacuum baking revolution

To optimize in-store baking efficiency, the UDO baking technology is one to watch. It stands for Univac Double-bake Oven and is powered by Cetravac AG’s patented innovation. Developed under the bakeXperts brand, the UDO opens the door to a new world of baking in-store.

+The UDO can bake frozen, ambient-stored raw dough, or parbaked products such as rolls, baguettes and even larger loaves and cool them to perfect-to-eat level in less than 5-10 minutes. It does so while achieving perfectly even heating and retaining all product characteristics, consistently. How is such a process, which is nothing short of revolutionary, even possible? The answers are in vacuum conditioning. The process steps are straightforward: the frozen product goes into the preheated oven. In a matter of seconds, a vacuum is created, removing all air from the product’s pores and clearing the way for steam. The steam is then used to heat the product, a highly-effective process that only takes seconds and boosts crumb and crust qualities. Simultaneously, infrared radiation heating is deployed. With starch gelatinization comes heightened freshness, as this process delivers moisture to the crumb. The final step is vacuum cooling, again a seconds-long phase, which further stabilizes the structure of the baked product. The speed of the baking-off process makes it possible to react to fluctuations in demand at very short notice, thus minimizing unsold residual stocks at the end of the day.

Baking efficiency, comprehensively covered

The control system is designed so that the operators only need to place the goods on a tray, assign them to a product image and press the start button. The control system can also be integrated into other management systems such as Semco One or Shop IQ. In this way, new products can be added centrally into the interface, while also enabling comprehensive control of the oven.

There is an entire array of adjustments that can be combined to improve baking quality and efficiency. To embark on an optimization process, the goals should clearly be defined at first, before building a path to them: “What is meant by optimization, process organization, the time and effort required, the energy costs, the availability of products, or their quality? Which sub-goals are in the foreground at the same time, which can definitely vary from one company to another? When developing the UDO vacuum baking oven, we focused on a holistic approach because it is important to us that economy and product quality are not seen as conflicting opposites,” explains Adolf Cermak, founder and President of Cetravac AG and bakeXperts.

The economic perspective

Looking at the entire process, from start of production to sales, the UDO can shorten the processing time by 40-70% compared to conventional in-store baking, depending on the product, and save considerable energy and labor force requirements, respectively. In addition, it also supports raw materials savings, because baking losses are reduced to a minimum, thanks to the accurate control of the water balance in the baked goods. With this method, there is no volume or weight loss even if, initially, up to 10% less dough was used. Moreover, the stability of the process means that larger batches can be produced efficiently and quickly, with lower manufacturing costs, whereas certain products are only made in small quantities with traditional ovens to ensure their quality.

Yet another advantage of this process is that products do not usually require cold storage between initial baking, in the production facility, and final baking, in the store (depending on the duration of storage before the final preparation). “This saves refrigeration and/or freezing and the corresponding transport costs and contributes to saving energy overall,” the specialist highlights.

It is a sustainable process not only from a savings standpoint: “Since the ‘refrigerant’ in vacuum cooling is water and nothing else, it is the most ecological cooling process available today,” Cermak points out. Moreover, only products containing water can be vacuum cooled, meaning the baked goods themselves. Carrier materials (baking trays, rack trolleys, pans, etc.), which are unavoidably cooled in the conventional cooling process, are left out with vacuum cooling, which lowers the total weight of the mass that is to be cooled by approximately two-thirds. Along with this reduction, the corresponding cooling capacity or energy consumption also goes down.

Product quality considerations

Controlling water balance greatly contributes to product quality. “A 1-kg parbaked bread, for example, can be baked to completion (with a core temperature higher than 75°C) and cooled to slicing temperature within 6 to 10 minutes. It is clear that this promotes moistness and freshness for hours. Even products, in which starch retrogradation has already begun, can thereby be restored to their former freshness. The stabilization of moistness, shape and crispness immediately after baking opens up new opportunities in

Product group

Advantages

Small pastries, e.g. rolls, baguettes and ciabatta Shorter process time, less baking loss, volume stability, longer crispness than with a conventional baking method, process reliability and certainty

Fine pastries such as croissants and Danish Shorter process time, halved baking loss, more aroma and significantly improved and longer-lasting volume

Large bread loaves including double-bake

Filled products such as tarts, strudels, etc.

Snacks such as pizzas, muffins/crumpets, pretzels

Packaged goods

Fresh large loaves from an in-store vacuum oven in a cycle lasting a matter of minutes, no loss of moisture and therefore of weight, long-lasting freshness

Volume without E-numbers, filling remains airy, fills the product even after baking and does not become greasy

Very short process time, juicy, crisp bottoms and attractive-looking outer surface, at eating temperature immediately

Baking-off pre-packaged breads/toast breads in-store according to demand the highly topical market of delivery services that rely on quick availability,” Cermak adds.

Another relevant case is that of filled products such as snacks or sweet Danish pastries. When baked in conventional in-store ovens, the end product features a compacted filling, lying in a cavity. With vacuum baking, the product’s structure is preserved, hardly any cavities occur, and the product comes out of the oven with a stable volume and warm to the touch. “The visual appearance of such a pastry is completely new,” adds the company’s founder, a result that also applies to pizzas.

How efficient is vacuum baking?

When using vacuum conditioning, savings already start with the pre-baking stage, which is usually 20-25% faster than with traditional technology, for any type of product –be it a baguette, a ciabatta, or a pan bread. Vacuum technology also makes the second baking phase, which is done in-store, significantly shorter. Cermak explains: “In the UDO vacuum oven, the applied vacuum is only enough to just exceed the gelatinization temperature of the starch. Steam is then added to the baking chamber. Because the heat in the hot oven goes to the coldest point, which is inside the bread, the steam releases its heat to the crumb by condensing into water. The crumb is heated over the gelatinization temperature by absorbing the hot water. This process freshens up the crumb. In the next step, the bread is cooled by applying vacuum again and by evaporating water from the crumb down to a temperature at which it can be sliced.”

The adjoining table highlights the characteristics of different types of processes. The products pictured clearly show the positive influence that baking in a UDO has on the shape and stability of the products. With frozen dough pieces, which usually have to go into a proofer or at least be partially or fully thawed out before conventional baking, the total processing time is reduced by up to 70%. Just as importantly, the demand for the expertise of responsible employees is also minimized. The products can go from the freezer directly into the oven, without having to worry whether the proofing is perfect or not.

A patented innovation

Prof. Dr. Friedrich Meuser is an internationally renowned authority in the field of cereal and bakery technology. He commented about the process and technology developed by BakeXperts: “The oven is sensational. Cermak has approached the whole thing with an engineer’s eye, and you may ask yourself why no one has done that before him.” Meuser explains the theory and the core of the patented innovation behind the UDO: “Harry Levine and