To ensure product consistency, the name of the game in producing cakes is accuracy — accurate ingredient mixing, accurate aeration, accurate transferring, accurate depositing. Without accuracy and control, batters can have too much or too little air coming out of the mixer, lose volume in the transfer to the depositor and end up on the edges of pans, the conveyor belt or, worse, on the floor.
Mixing a batter well at the beginning of the production line can set up the pumps and depositors for success in getting a consistent product to the oven, said Steve Crocker, product sales manager, The Peerless Group, Sidney, OH. Consistency in the mixer will ensure consistency in the depositor and beyond in the cakemaking process.
Eliminating the opportunity for human error has a major impact on making sure the batters coming out of the slurry and continuous mixers are the same every batch of every shift of every day.
“The baker must precisely control all of the variables that affect the batter during the mixing process such as time, temperature, pressure, aeration and ingredient batching,” said Kevin Wilkinson, president, Tonelli Group, Woodside, CA. “Tonelli mixers are specifically designed to control these variables and reduce the chance for operator or machine errors, which could affect the final outcome of the batter.” Tonelli’s PLCs control the mixing rpm, process time, temperature and mixing under air pressure or under a vacuum. Companies can choose automatic or manual ingredient batching with operator prompts and checks.
“By controlling the variables such as the pressure, temperature and rpm of the agitator in each of the many modular mixing units, we can deliver very consistent, high-quality and high-capacity cake batter, icings and whipped toppings,” Mr. Wilkinson said.
Robert Peck, vice-president of engineering at E.T. Oakes Corp., Hauppauge, NY, said the company has simplified its PLCs with a touch screen that enables operators to choose recipes with preprogrammed variables. Line supervisors can lock certain parameters to prevent second- and third-shift operators from straying from the original recipe used during the first shift, which helps the bakery’s product remain consistent.
Along with a simplified PLC, E.T. Oakes automated density control of the batters with mass flow meters and mass gas meters to control the fall of specific gravity precisely. The company’s slurry mixers combine dry ingredients without incorporating any air before pumping the slurry into a holding tank and then to the continuous mixer where the batter is aerated.
“Typically, customers want to aerate the batter to a certain density, and when you do it in an open-top mixer where the air is being incorporated from the atmosphere, you can’t control it very well,” Mr. Peck said. “Our mixers don’t incorporate any air until we get to our continuous mixer — which is a closed, pressurized environment where we inject the air by the flow meter, so we know exactly how much air is going into the product — and that’s how we control the density very precisely.”
After mixing, the cake batter moves to the depositor, but getting there can cause problems with batter consistency. Bakers can use either automatic pumps or manually transfer batter.
To increase production speed and eliminate the opportunity for human error and sanitation problems, many bakeries rely on pumps to send the batter directly from mixer to depositor in a
However, some pumps force the batter through small apertures, which stretch and break down the batter. The batter loses some of the air that the mixer precisely incorporated, resulting in lost product volume. This becomes especially critical when dealing with delicate cake batters that incorporate a lot of air such as angel food cake.
“Historically, moving batter mechanically has been quite a challenge for bakers,” said Stewart MacPherson, vice-president, sales and marketing, Unifiller Systems, Inc., Delta, BC. To address this challenge, Unifiller offers the Hopper Topper Max, which pulls batter from the bottom of the bowl up through the center of the pipe. “In effect, it’s scooping the product up from the bottom of the bowl — almost like a hand scooping.”
To prevent batter stretching, this transfer system doesn’t use gears or rollers. The Hopper Topper Max also ensures accuracy by using an infrared sensor in the hopper to alert the suction pump when the hopper above the depositor is full. That sensor helps retain the level in the hopper to maintain the batter’s specific gravity.
To meet customers’ product transfer needs, Hinds-Bock Corp., Bothell, WA, not only has gentle pumps to move batter without injury but also tailors the transfer path to minimize opportunities for the batter to change.
“If batters are very light in specific gravity, then we take care to make certain that the flow path is very short,” said Lance Aasness, vice-president, sales and marketing.
Hitting the mark
Bakers can take specific steps to ensure that accuracy and product consistency extends to depositing as well.
“If batter consistency is very light in viscosity, [the depositor] uses positive shutoff spouts so [it] doesn’t drip or trail the batter from deposit to deposit,” Mr. Aasness said. “If the batter is quite viscous, then we will use diving spouts that deposit from the bottom up to help spread the product and prevent it from mounding up.”
With high ingredient costs, bakeries can’t afford to lose product to equipment errors as simple as a
depositor dripping, trailing or missing the pan all together.
“If it’s not accurate, then they’re basically giving away money and uptime or yield,” Mr. Aasness said, adding that Hinds-Bock’s positive shutoff valve makes a clean deposit without trailing batter from row to row or dripping.
Unifiller offers servo-driven pistons as an option on its depositors, which means the volumetric system that measures out cake batter for the pan below is controlled by the accuracy of a computer instead of relying on mechanics.
“We’re able to preselect by menu the weights, deposit speed and even the motion of the piston pushing the product out,” Mr. MacPherson said. This works in conjunction with Unifiller’s automatic checkweigher, which detects when a change in weight has occurred and tells the servo-driven piston to adjust accordingly. After two or three trays, the computer recognizes the declining weights as a trend and increases the deposit volume until it reaches the target weight again, he explained.
Instead of using pistons to deposit cake batter into pans, E.T. Oakes’ depositors rely on a pressurized manifold to accurately fill the pans. According to Mr. Peck, the amount of batter that goes into the depositor is exactly the amount that comes out.
“A new pump will be very accurate for a while but will become less so with wear, and you won’t always know what you’re getting when it’s pumping,” he said. By adding a mass flow meter, E.T. Oakes’ depositor will speed up the rate of the pump to compensate for any pump wear or changes in the batter.
Starting with a precisely mixed batter and using computers and automation to adjust the process for any changes along the way will assist bakers in knowing that the pans going into the oven carry the product they meant to bake.