Protecting quality while dividing
July 25, 2016
by Charlotte Atchley
The divider offers bakers control over their raw material costs. Through accurate portioning, bakers can cut down on waste and improve yield.
Dough can take a beating when it goes under the knife, and product quality becomes a concern for bakers, particularly those who make open-cell bread and rolls. “In artisan-style products, the dough is alive,” said John Giacoio, national sales director, Rheon USA. “It’s ever-changing. From the beginning of a batch to its end, that dough is beginning to gas out, and the specific gravity of the dough does not remain constant.”
From a mechanical standpoint, it’s important that the divider treat the dough in a gentle fashion to maintain the structure created in the mixer and during fermentation.
Tolerances between ram, knife and pistons must be very tight, according to Rob Francis, chief bakery engineer, Baker Perkins. This is necessary to maintain the dough’s volume while pushing it through the divider and to minimize any losses of air or dough via clearances in the ram-and-knife assembly.
The trick is to choose the right construction materials to maintain those tight tolerances throughout the life of the divider. “Your main chamber should be made from a hard, durable material, and the ram, knife and pistons you ought to make from materials that are softer. That way, you avoid aggressive friction action from the different components,” Mr. Francis said.
Balancing machining stress with gentle handling of doughs yet maintaining portion accuracy is tricky. To achieve that balance, Baker Perkins applies the correct amount of pressure on the ram as it fills the divider pockets with dough. Simple things like changing the sequence of knife, ram and pocket to improve the efficiency of dough movement as well as implementing electronic servo technology help dough move through the divider without shearing. “The dough shouldn’t go around sharp corners that cause high levels of shear in the divider,” Mr. Francis said. “You want to shear the dough in the mixer, not in the divider.” With these advances, Baker Perkins has seen 15 to 20% reduced cell losses in doughs portioned by its ram-and-knife dividers.
Consistent dough handling helps maintain dough rheology, which in turn helps maintain accuracy through the batch. If the rheology remains the same, so will the weights. “The most consistent dough handling occurs when it is moved gently with reduced stress and minimal temperature rise within a batch and from dough batch to batch,” said Cesar Zelaya, Handtmann. Hantmann’s VF 600 B divider maintains the dough’s characteristics with its gentle handling. The company’s vane-cell technology reduces product stress and brings dough along a shorter travel path, minimizing the opportunities for stress.
Rheon’s V4 stress-free dividers are gentle enough to be used on high-absorption artisan breads and laminated doughs. The company’s gravimetric method for weighing and cutting divides gassy doughs accurately without exerting any mechanical force on the dough. At this year’s International Baking Industry Expo, Rheon plans to show its Flex Width Divider, which allows bakers to change the width of the dough being put on the conveyor, thus cutting the amount of trim.
“Reduced trim improves your quality because you’re not feeding excess trim back to the mixer or back to the machine,” Mr. Giacoio said. By reducing trim dough, bakers enhance dough quality.
Servo technology also helps maintain dough consistency by limiting the amount that needs to be reworked, according to Roger Romsom, sales director, Kaak Group, thus preserving product quality.
Pocket configuration also plays a part, he said. The same is true of the hopper, a component of dividing most don’t consider, Mr. Romsom said. Dough can get stuck on hopper sidewalls, and the design of the hopper can needlessly push dough through a funnel, damaging its cell structure.
Dividers are indeed the cash register in the bakery. It’s where the baker’s margin can be gained or lost. “Accurate scaling is critical to the profitability of any baking operation,” said John McIsaac, vice-president, strategic business development, Reiser. “The closer our customers can maintain their scaling to label weight, the more money they can make.” The further scaling gets from label weight, the more money bakers could lose. By portioning precisely and gently, bakers can deliver to customers — and consumers — exactly what they are promised on the package: quality bread at a very precise weight.