Regulating dough temperatures is key to producing bakery products that are top quality. The longer the mix time, the more energy that goes into the dough, which raises the temperature.

“Effective temperature control in dough preparation involves several factors,” explained Mélanie Gay, marketing manager, VMI. “One of them is the temperature of raw materials. Managing the temperature of water or flour for instance can help maintain a lower dough temperature. The mixing operation inevitably generates heat, but by optimizing the design of your mixing tools and their ratio to the bowl, you can minimize heat buildup during the process. To ensure precision, mixers can be equipped with temperature probes to ensure that you consistently meet your temperature targets.”

Equipment manufacturers offer various sensors that can monitor temperatures in the bowl as ingredients are mixed.

“All of our Diosna mixers have the option to add a temperature probe integrated in the bowl scraper,” said Ronald Falkenberg, regional sales manager, Diosna. “We also offer the option to mix according to temperature instead of time.”

Zeppelin’s Codos Continuous Mixer/Kneader measures dough temperature at the outlet of the dough.

“This feature enables operators to be alerted immediately to any temperature changes and react accordingly to keep the dough within desired parameters,” said Shawn Hasley, director of food system sales and services, Zeppelin Systems. “Additionally, this machine is equipped with a double-jacketed mixer trough that provides effective dough cooling capabilities.”

And PLC-based control systems with recipe software can also monitor doughs for a variety of variables.

“Receiving signals from transmitters installed in the mixer, PLC-based control systems display process variables in real time and reduce the need for manual adjustments, such as temperature regulation, vacuum control, cycle time and agitator speed manipulation, valve operations, etc.,” said Erin Dillon, media and marketing coordinator, Charles Ross & Son Co. “PLC recipe controls eliminate human variability by automating these tasks, ensuring that the same processing steps are followed precisely each time and seamlessly documented as well.”

Bakers have a variety of options at their disposal to control temperatures in the mixing bowl, some that have been around for a while and others that are newer.

“The mixing element used in horizontal batch mixers have been the same for a very long time,” said Terry Bartsch, executive product manager, AMF Fusion, an AMF Bakery Systems brand. “The starting temperatures of the ingredients going into the mixer can vary from season to season, particularly because, where is the flour stored? Typically, in silos outside the bakery. If it’s 100°F outside, your flour’s going to be 100°F inside the mixing bowl. There are only a few things that can counteract the warm flour temperatures. The most effective way is to use chilled water.”

One of the newer technologies on the market is stream ice, which is basically water mixed with tiny ice pellets that can help counteract heat and keep dough temperatures within limits.

“There are companies now that will literally take the water going into the mixer and make it a slush so you can mix the dough at a much cooler temperature,” said Jim Warren, vice president, Exact Mixing, a Reading Bakery Systems company. “This is a recent development over the past two or three years. It works in a batch or continuous mixer, but it’s particularly well suited for continuous mixing because you are literally metering the same way, but you’re converting to a slush as it goes into the mixer.”

Mr. Bartsch said that stream ice can significantly lower the temperature of the dough. It’s not commonly being used in bakeries at this time, but he expects it to gain traction soon.

“Like with every technology, the baking industry is conservative, and it could take some time for a good idea to take off,” he said. “I think you will see it; it’s just a little too new.”

Other ways to cool doughs include using jacketed mixing bowls that have glycol running through them.

“At VMI, we use double-jacketed bowls with glycol circulation, and the key is to ensure that we maximize contact zone between the bowl and the dough to have even cooling and limit dough heating,” Ms. Gay said.

AMF takes a multi-pronged approach, which includes improved cooling to the mixing bowls through bowl design.

“We’ve designed a refrigeration jacket that maintains the strength of the bowl sheet itself while using a thinner bowl sheet than what is normally used in the industry to increase that heat transfer coefficient,” Mr. Bartsch said. “We also offer a Refrigerated Agitator Cooling System, Bowl End Cooling and a Refrigerated Breaker Bar to increase the overall surface cooling area so we can provide our customers with the final dough temperature they require.”

One solution bakers can turn to is chilling the flour, although it’s not commonly used, Mr. Warren explained. The good news for those chilling flour is it likely will only be needed for a month or two during the hottest part of the summer and not year-round.

“Another idea for customers is to put their silos indoors because if you think about it, the flour is two-thirds of the ingredients in your product, so it’s the biggest driver of temperatures,” he said.

Jerry Murphy, vice president of sales, Gemini Bakery Equipment, said Wendel-style mixers mix more by compression than friction, which reduces temperature increases and allows for better consistency.

This article is an excerpt from the November 2023 issue of Baking & Snack. To read the entire feature on Mixing, click here.