PRODUCTION
Consistent quality of liquid metering Storing and supplying viscous and liquid dough ingredients for bakeries is a complex subject.
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++ Pipework for liquids
“Ordinary” bread contains numerous constituents, some added as raw materials (flour, water, yeast etc.) and others as intermediate products (brine, bread slurry, cold- or hot-soaked grain). Correct handling and accurate metering of all these liquids according to the recipe are decisive requirements for consistent dough quality. Liquid metering technology Medium-sized industrial operations and large-scale bakeries use partly or fully automated processes to produce bread. These processes can take place continuously or batch-wise. Depending on the level of automation, a variety of production, processing and storage plants are used to implement the various baking recipes to yield a clean, hygienically faultless product and a reproducible process. The focus is always on a flawless, consumer-oriented end product. Liquid raw materials are often delivered to the bakery in ready-to-use form. Depending on the quantity required, transport takes place in road tankers, IBC containers, drums or canisters. Suitable acceptance, conveying, storage and metering systems are available for each of these delivery units. The configuration of liquid systems in the areas of temperature adjustment, product activation, cleaning etc. is implemented in a customer-specific way. The emphasis is on handling raw materials hygienically and in accurate compliance with the recipe. A few of the raw materials are used as intermediate products. Liquid yeast, for example, is prepared by dissolving block yeast in process water directly at the customer’s premises, after which it is stored, then added to the downstream process.
Sugar dissolver plants are used to produce various sugar syrups or invert sugar on the spot. Production of salt brine by the factory itself avoids transporting water, since only the crystalline component is delivered. These intermediate products, which can also include sourdough production, are then correctly stored and fed into the manufacturing process in the correct amount required in a given time. Process water In addition to flour, the second main constituent of bread dough is water. Water is used in a variety of forms. As well as direct addition as cold water, warm water or temperaturecontrolled water, a non-negligible proportion of water is also contained in liquid yeast or brine. Further amounts of water occur when processing cold-soaked grain or in residual bread recycling, and these must be balanced with the recipe. The simplest implementation of water metering is directly from a ring main. This necessarily involves monitoring the throughput flowrate and temperature and adjusting these in accordance with the recipe. For accurate, reproducible metering, the water should be provided at a consistent pressure and constant temperature, and in the amount needed per unit time. If the water temperature is optimum, the dough can be processed as required in the following process steps. The WinCos recipe control system calculates the correct water temperature by evaluating the various raw materials temperatures relative to the recipe-based dough setpoint temperature specifications. The energy input in the mixer and the subsequent dough resting time must also be taken into account as influencing factors. The result: a consistent quality of dough that accurately reflects the recipe and has optimum characteristics for further processing. www.bakingbiscuit.com 03/2018
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