Wires from an oven profiler are inserted into Kaiser rolls, which are located on the left and right sides of the conveyor. The oven profiler monitors temperatures on both sides of the oven.
Oven profilers go by many names in the baking industry, including thermal profilers and data loggers. Despite the name, they all perform similar functions: traversing the lengths and widths of ovens taking constant measurements of temperature and humidity, in addition to internal temperatures of bakery foods.
Oven profilers are designed to take the guesswork out of oven control and provide bakers with added quality control measures. There are several suppliers of these systems in the industry, and they say payback for the tools is less than a year. What follows are examples of how profilers have improved operations at several bakeries.
Example No.1 In Mexico City, about 35 bakers from a large bakery took a daylong class in profiling. The day was split in two: classroom in the morning and baking applications in the afternoon. The instructor, a representative of an American bakery equipment manufacturer, required a translator to communicate his message in Spanish.
In one day, not only were the bakers sold on the benefits of oven profiling, but so was upper management. “The bakery immediately decided from a corporate standpoint that they were going to roll out oven profile training in 10 bakeries,” the equipment manufacturer says. “They now have 20 bakeries between Mexico and South America using oven profilers.”
In addition to using oven profilers to monitor oven efficiency, the baking company also has established a weekly reporting system that forces its bakeries to submit reports on oven performance. Detailed oven performance specifications also were created for each bakery, due to the varying environments where the plants are located. Such environments made it impossible to establish a consistent model throughout the bakery’s entire plant network.
By using profilers in this serpentine oven, a Midwest bakery has reduced its baking time for Kaiser rolls and significantly increased capacity.
Example No. 2 A Kaiser roll bakery was running products through its tunnel oven for 16 minutes. After running an oven profiler through the oven and checking internal product temperatures, the bakery discovered that at 10 minutes, its products already had an internal temperature of 200°F. The bakery reduced its baking time for these products to 12 minutes and also significantly increased capacity.
In addition, product quality and shelf life were improved because the oven was no longer over-baking or drying out the products. “This was a brand new oven, too,” the equipment manufacturer said. “[The bakery] had the best technology in the world, it just didn’t have the operational understanding.”
Example No. 3 A large national bakery was running bread through a tunnel oven for 22 minutes. After running an oven profiler through the oven and collecting data, the company realized that it could decrease its bake time to 19 minutes. The bakery calculated the cost savings in natural gas alone and was shocked at the savings: $4,000 per month per oven.
Example No. 4 A large cracker manufacturer was having staling problems with its products that ran through a 300-ft. tunnel oven. The 3-minute bake cycle sent products through the oven at 100 ft. per minute. After running an oven profiler through the oven, the cracker manufacturer realized it was baking the crackers too long, which took all the moisture out of the products. The cracker manufacturer increased the speed of the oven and boosted throughput by 20%, allowing the company to cut back from two 8-hour shifts to one 10-hour shift.
By using profilers, one large west coast bakery that produces pumpkin pies has reduced cycle times, improved output and cut its natural gas usage.
Example No. 5 A large bread manufacturer was averaging between 500 and 600 complaints per million loaves. The main problem was varying loaf sizes due to oven efficiencies and oven adjustments that actually made things worse. The company purchased an oven profiler, and within 90 days, the complaints fell to three per million.
Example No. 6 A large sandwich-roll bakery was having a problem meeting customer requirements for a brown crust. The bake cycle was nearly 21 minutes, but initial profile runs indicated dough
temperatures were reaching 200°F 11 minutes into the baking cycle due to excess steam and lack of venting. It was determined that all dampers were closed and steam was exiting the end of the oven. By opening dampers, the bakery darkened roll color to a satisfactory level, and the internal temperature was lowered at exit, reducing the staling effect caused by excess heat.
Example No. 7 A large bakery needed to determine proper baking time for a wheat sandwich line baked in an 84-ft. continuous impingement tunnel oven featuring eight zones. By using profilers, the bakery determined internal dough temperatures were reaching 200°F at 74% of the 19:30 baking cycle rather than at the target rate of 85%. To slow internal baking, overall oven temperatures were reduced an average of 15°F. This change has resulted in the bakery saving more than $3,000 per month on natural gas.
Several bakers from Grupo Bimbo learn about the benefits of using oven profilers during a daylong class held in Mexico City.
Example No. 8 A bakery was concerned that the actual relative humidity throughout the proofing cycle was different than what the static measurement system was reporting. The static system reported relative humidity in the 90% range, but the product consistently looked underdeveloped and the dough skins appeared too dry. An oven profiler confirmed the relative humidity was only 63% and that a better static system should be installed or existing equipment calibrated. The bakery improved product quality, volume and appearance.
Example No. 9 A cookie manufacturer noticed an excessive amount of cookie tops with cracks. Profiler data indicated oven temperature was too high and dough temperature reaching 200°F too quickly. The manufacturer lowered the oven temperature, lessening cracking significantly and improving product color uniformity and desirability.
Convinced that oven profilers are a viable option for your bakery?
The use of oven profilers in the baking industry is growing as skyrocketing operational costs threaten to further reduce already shrinking margins. Oven profiles offer an affordable tool that improves efficiencies and eliminates human error.
More than 200 employees of Grupo Bimbo who work throughout South America have been trained on oven profilers. Shown is the company’s first class to graduate from a daylong thermal profiling class in Mexico City.
“The main problem is that a lot of the bakers on the floor don’t have an understanding of how the oven works,” one manufacturer of profilers says. “We call them tweakers because they’re constantly playing with knobs on the oven.”
“With all of the consulting and training I have done, at least 70% of bakeries are baking their breads much longer than they need to,” another manufacturer of oven profilers says. “A lot of bakers stick a thermometer in the bread and get an idea of what the core temperature is, but they don’t know what it really means.”
Using thermal oil to save energy For years, oven manufacturers who relied on thermal oil as a heating source touted the oil’s ability to reduce energy costs. However, where was the proof to validate this claim? One manufacturer of these systems sought to prove this theory by installing gas meters at a large bakery that operated a 15-ft., 6-in. wide tunnel oven and a 55-in. wide vertical oven that was heated with thermal oil. The lines ran similar products: full sheet white and yellow cakes.
The results were black and white, the manufacturer of the thermal oil oven says. “The tunnel oven was averaging 40 cubic ft. of gas per hour and the thermal oil oven was averaging 29.2 cubic ft. per hour,” the manufacturer says.
Industrial thermal oil ovens require a remote equipment system that heats and circulates oil throughout the system. Many bakers place this equipment in a separate room away from the production floor. One manufacturer says the equipment takes up about 10-sq.-ft.
Although proven data exists about the energy savings of thermal oil, the initial costs of these ovens run significantly higher than traditional ovens. One thermal oil oven manufacturer estimates that the systems cost about $400,000 more than traditional ovens.
