An efficient fryer keeps color and texture consistent on both sides of the donut.
Keeping cake donut lines humming with fresh, symmetrically-formed products rests with smooth operating production lines. Key systems such as the mixer, depositor/cutter and fryer influence how cake donuts look and taste.
To maximize favorable production quality for cake donuts, one donut industry source says that bakers should properly setup and consistently monitor their production lines. And this starts with mixing.
" The most important concept with cake donuts is consistency," one donut industry source says. "Mixing times are absolutely critical, and they have to be timed to the second. That is the nature of the beast."
Mixing donut batter
As with other bakery foods, precise ingredient measurement, carefully controlled mixing time and speeds, and control of batter temperature are essential. Cake donut batters are almost universally mixed with vertical mixers that use a paddle beater. This prevents dough from becoming deformed later in the manufacturing process. Bubbles that occur in cake donut batter are caused when the batter increases in temperature, which activates the leavening system. To prevent bubbles from forming in the batter, bakers can pour water into the mixing bowl before adding donut mix, one donut equipment manufacturer says. By adding water into the mixing bowl first, bakes also can prevent dry pockets in cake donut batter.
Improper mixing also affects cake donut dough's ability to rise at the desired time during production. Cake donuts use chemical leavening systems, which are affected by time and temperature. When batter temperature increases or decreases by less than five degrees, cake donut appearances are affected, one donut industry source says. When mixing speeds change and the cake donut formulation has not been modified, the cake donut dough will toughen, which leads to difficulties with cutter/depositor and frying systems.
Once mixing is complete, cake donut dough needs to rest before production can continue. This floor time affects cake donut dough performance further down the production line. Precise floor times allow dough to fully hydrate. If cake donut dough rests longer than intended, gas enters the dough, which changes its viscosity.
Cake donuts use chemical leavening systems, which are affected by time and temperature. When batter temperature increases or decreases by less than five degrees, cake donut appearances are affected.
"There is a window of opportunity where you can get a good, quality product," one donut industry source says. "If the line shuts down or another other delay, dough that has not been placed in the depositor should be dumped rather than ran through the system."
Changes in dough viscosity also affect cutter/depositor operation. Dough viscosity rapidly changes when cutter/depositor heads are too close to the frying fats. When cutter depositing heads are too close to frying fats, the high fat temperatures heat the depositing heads. This causes the dough's leavening system to accelerate, and the dough will start forming a thin crust within the depositing head.
Problems also arise when depositing heads are too far from the fryer's oil. Oil splashes occur when cake donuts have a greater distance to drop.
Once submerged into the frying oil, cake donuts crash into the drop plate, which can cause donuts to stick, which prevents them from rising in the desired time. As a result, the donuts remain submerged for too long, and donut's surface skin seals with a thin crust. The leavening then causes the donut dough to expand, causing an eruption that leads to deformities.
Bakers can adjust the cutter height from the frying oil to alleviate this problem. The cutter's depositing heads should be between 1 to 1.5 ins. from the surface of the frying oil. The drop plate should equal the same measurement below the frying oil. After dropping from cutting systems into the frying oil, standard cake donuts should not stay submerged longer than about seven seconds, one donut equipment manufacturer says.
Cake donut frying
After dropping from cutting systems, cake donuts flow through fryers, which add the final touches to a cake donut's appearance. Problems arise when inconsistent frying temperatures and lackadaisical cleaning practices occur.
Oil temperatures affect taste and texture. For a consistent, high-quality cake donut, fryers should keep oil temperature between 360°F and 385°F, one donut industry source says. Keeping color and texture consistent on both sides of the cake donut also rests with the fryer. Typically, the first fried side of the cake donut has a more uniformed color, and the opposing side usually has more fat absorption. To improve color and absorption on both sides, bakers can move the flipping unit to increase or decrease frying times. This change gives bakers flexibility in modifying frying times on both sides of the donut.
During frying, 85% of the total oil in the fryer is absorbed by the cake donuts. If some of the oil transforms into free fatty acids, the cake donut's leavening system can prematurely activate. Free fatty acids are formed when fat break down occurs. These fatty acids separate from the glycerol portion of fat molecules. Free fatty acids are indicators of proper refining techniques and frying processes, one donut industry source says.
An accumulation of free fatty acids during frying can impact how cake donuts look after frying. These fatty acids occur when excess dry ingredients or dough particulates enter the fryer and mix with frying oil. Any material that has the ability to burn can cause free fatty acids to occur. Preventing these particulates from entering the fryer extends the life of the oil by reducing fatty-acid formations.
High oil temperatures can cause fat break down. In between donut frying runs, it is a good practice to lower oil temperatures to 250°F, one donut industry source says.
Frying oil also should be filtered once a week. The shallower the kettle, the more frequent oil should be filtered, one donut fryer manufacturer says.
Fryers also should be cleaned regularly. Strict cleaning standards prevent fryer accidents. According to one donut industry source, if water enters the fryer, oil turns vaporous and a "grease bubble" can erupt and burn employees. After cleaning, water can hide in small crevices within the fryer, and drying techniques may not mop up all the water. To prevent any dangerous situations, the fryer should be turned on at a low temperature to eliminate any left over moisture.
By implementing these cake donut production methods, bakers can create a consistent donut. From the mixer to the fryer, cake donuts require accuracy in time and temperature throughout the production process.