Let cool. These two words are found in most household baking recipes, and they’re very important. For good reason. Bakers know not to handle bars and cookies too soon or they will crumble to pieces. Chocolate that is melted for molding, drizzling, or enrobing must cool and harden before it can be served. In the trending bar manufacturing category, however, the need for cooling isn’t quite as well understood. We field a lot of questions about cooling from new processors who are starting to automate the bar manufacturing process. We’ll try to answer them here.
Why do granola, protein, cereal or other types of bars need to cool?
Whether as children or adults, most people have made a batch of Rice Krispie Treats in their own kitchen. The process involves melting butter and marshmallows, and then combining the mixture with rice cereal. The gooey warmth of a fresh batch of Rice Krispie Treats is very similar to the consistency of most commercially-made bars right after they’ve been pressed. Have you ever tried cutting a pan of just-blended Rice Krispie Treats? The mixture likely stuck to your knife or fingers, and then melted right back together. For the treats to be cut into squares, they first must cool. Granola, protein and other types of bars also need to cool before cutting.
Product temperature affects more than just cutting, however. Covering or packaging a product that is too warm can also lead to condensation as they continue to cool. In a commercial setting, condensation buildup inside the packaging can lead to mold and other bacterial issues. In addition, cooling will create a firmer product which is necessary for downstream packaging to work properly.
Unlike baking in your own kitchen, however, commercial food processors can’t stop production for hours while their products cool at room temperature. “Let cool” is a step that simply takes too long. Smart manufacturers draw the heat out of their bars as quickly as possible. They use specially-designed equipment to speed up the process.
What equipment do I need to quick-cool bars?
For processors forming small batches or cutting bars by hand, freshly pressed slabs are often placed into baking trays. Those trays are then placed in racks, which can be left to cool at room temperature or rolled into a walk-in cooler. Egan Food Technologies offers an optional retractable conveyor on our slab forming and extruding lines for bars being cooled by this method.
Cooling tunnels, sometimes called cooling conveyors, are popular among manufacturers who desire a more automated solution without the starts and stops in production caused by the racking method. A machine called a slab line provides this automated solution. After the dough is formed and pressed by compression rolls, the slab moves along a conveyor through a tunnel where it is blasted with the cool air of the tunnel’s chamber. From below, the bottom of the slab is cooled by chilled deck plates, quickly reducing the slabs internal temperature.
Upon leaving the tunnel, the cooled slab can continue along the conveyor to a slitter wheel and guillotine cutter, which will create bars with crisp-cut edges for consistent production quality. From forming to slicing, the bars never have to leave the production line.
Egan Food Technologies is the only US manufacturer that offers a full slab forming line that presses, cools and cuts bars. In addition, our equipment is modular and expandable, so entry level manufacturers can both affordably automate and plan to scale up in the future.
How do I know which equipment will work with my process or recipe?
While Egan Food Technologies’ cooling tunnel can achieve temperatures as low as 45 degrees Fahrenheit, the internal target temperature of the bar is typically 62 to 65 degrees. At this temperature, the reduced tackiness of the product minimizes the residue that will be left on the bar cutter or guillotine, and cuts will be uniform across products.
Your product may vary slightly from this target temperature, and the size of the cooling tunnel your process requires also depends on the starting temperature and the speed at which your production line runs. For instance, slabs that are 95 degrees after pressing will require more time inside of a cooling tunnel than slabs that begin at 85 degrees. All of these factors make up your product’s cooling profile.
Manufacturers who are unsure of their cooling profile can take advantage of Egan Food Technologies’ cooling test unit. We can recreate your manufacturing process in our test lab or bring our unit to your facility for on-site data collection. Our engineers will design a custom solution specific to your product, whether it’s a bar or food that benefits from cooling, such as cookies, granola, popcorn, gummies, or even fresh cut vegetables.
If you have a question on cooling or bar forming that we haven’t answered, contact us today.