Oct. 1, 2011
by Charlotte Atchley
Freezing can be a dessert manufacturer’s best tool when it comes to product handling. Cheesecakes slice best when frozen, said Mike Lawler, president, Lawler’s Cheesecakes, Humble, TX. And most bakers would much rather ice a cake that’s been frozen compared with one that’s at room temperature, explained Kirk O’Donnell, vice-president, education, AIB International School of Baking, Manhattan, KS.
Freezing systems help set icings, creme centers, frostings and sticky glazes on baked foods to save all the things that make dessert delicious for the consumer and not smeared on a belt.
Freezing desserts makes them easier to slice, handle, package and ship. Freezing also helps maintain moisture, flavor and texture. However, freezing can be a tricky production process. If done incorrectly, freezing can poorly affect the quality of a dessert. Freezing desserts takes time and can slow the production process, which costs the manufacturer money. With the right system setup and equipment, automated freezing can get the right freeze for the right product and keep the production line moving.
Freezing desserts requires a precise process. Cakes shouldn’t go straight from oven to freezer. They need some time to cool first. Mr. Lawler noted that if a cheesecake is frozen too fast, the top can crack or the cheesecake itself could change shape. To maintain a product’s quality, I.J. White Systems, Farmingdale, NY, offers a system that allows time for tempering before freezing.
Some desserts don’t fully set during baking, and the fillings of some hot-filled styles can still be quite liquid. “They need tempering to set the cake or filling,” said Peter White, president, I.J. White Systems. “We’ll do that with controlled refrigerated air, and then the desserts enter our Ultraseries 2 blast freezing system. This improves the aesthetic quality and keeps a smooth surface, potentially eliminating fracturing of the surface of certain dessert cakes.”
Despite freezing’s benefits for dessert manufacturers, freezing product can take time, money and, without an automated system, labor. Batch freezing methods can bring a production line to a standstill at the freezer. With automated continuous freezers, the baker streamlines production and saves money on labor and time.
“It always costs dollars when you go from continuous to batch to continuous to batch,” Mr. Lawler said. “If you go continuous, you want to stay continuous.”
To automate freezing, most bakeries choose linear tunnel or spiral freezers based on floorspace available and the product to be frozen.
Spiral freezers fit more belt into a smaller footprint. In the case of JBT Corp., Chicago, IL, the company’s self-stacking spiral freezer not only takes up less floor space than a linear freezer, but it also requires less height than other spiral systems. A side link welded to the inside and outside of the spiral conveyor belt eliminates the need for a track or cage in the freezer, and the belt stacks upon itself. “This allows 150 to 200% more belt compared with alternative suppliers, which is very useful in a plant with a low ceiling height situation,” said Andrew
Knowles, freezer sales support manager, JBT. Because a spiral freezer has more belting, products that need longer dwell times such as layer cakes get the time they need to cool off, which increases throughput.
Linear tunnel freezers don’t have as much room for flexibility because of their limited belt lengths. However, cryogenic freezing eliminates the time problem with low temperatures, freezing some products in just 15 minutes as opposed to 45 minutes to several hours, according to Ron Idol, business development manager, Air Liquide, Houston, TX.
JBT’s linear impingement freezers use centrifugal fans and impingement plates to create high-velocity air in the tunnel to cool and freeze product from the top and bottom. According to Mr. Knowles, this simulates a cryogenic freezer without the need to purchase nonrenewable cryogen gases.
Bakeries constantly fight the battle against coil ice buildup, which slows production. Generally, when ice forms on the coil of a freezer, the system must be shut down for defrosting. G&F Systems, JBT and I.J. White Systems have found ways to minimize the need for defrost cycles. According to Anthony Salsone, senior associate, G&F Systems, the company designed a coil that attracts ice to its nonmechanical surfaces, allowing much longer production runs without defrosting because the ice doesn’t interfere with the coil’s function.
JBT’s new sequential defrost methods manage frost buildup during production to maximize run times. I.J. White’s continuous production systems come with advanced defrost control, which uses auto-pressurization to dramatically eliminate frost and ice buildup on the coils. This extends the time between sequential defrosting, which saves on energy costs and lost production time, according to Mr. White.
CLEAN AS A WHISTLE.
With public scrutiny zeroing in on hygiene and sanitation in the food industry, food manufacturers look for ways to make plant sanitation easier, and automated freezing equipment is no exception.
Linde North America, Murray Hill, NJ, and JBT both have designed new freezers with sanitation being the guiding factor. After asking its customers what they wanted in spiral freezers, Linde found that cleanability was one of the biggest concerns and designed the Cryoline XF Cross Flow spiral freezer with a sloping belt and welds inside and out.
To reduce sanitation issues, JBT’s contact freezers use an inexpensive disposable film between the plate and product that acts as the conveyor belt, thus baked foods never touch the plate.
Air Liquide is also redesigning its food processing equipment with concern for cleanability and sanitation. “The old cryogenic equipment had a lot of nooks and crannies,” said Mr. Idol. “You’ve got belts that have interlocking mesh, all of which gives bacteria a thousand places to hide. Now we have freezers where you can reach everything in there and visually inspect it.”
To prevent food entrapment on a freezer’s conveyor belt, Ashworth Bros., Inc., Winchester, VA, made its Omni-Pro stainless steel freezer belts with a smooth 360° weld.
I.J. White offers a belt washer as part of its automated total cleaning package. The total cleaning package is an automated, clean-in-place system that washes down the product zone as well as enclosed areas. The system reduces man-hours needed for cleaning and keeps production efficient, according to Mr. White.
For large dessert manufacturers, freezing protects their products’ looks and tastes by helping retain moisture and shape. But freezing doesn’t come without its challenges — improving efficiency, reducing cost and easing sanitation. With the latest equipment developments, however, those challenges can be addressed.