Cake Donut Production Technical Help
 A cake donut is unique in that its is unlike that of most baked products. Cake donuts are deep fat fried, without a container or pan to control the shape of the product. The fry fat is not only the heat transfer medium but also becomes a major ingredient in the cake donut. A fried cake donut will typically contain 20-25% moisture and 20-25% fat of which 80-85% is absorbed fry fat.
A vertical cross section of a cake donut indicates it is made up of three zones:
(1) The crust or outer surface of the cake donut is usually a crisp, medium brown area. This area of the cake donut has been exposed directly to the hot fry fat, resulting in a loss of most of the moisture and it absorbed a relatively high amount of frying shortening. Moisture will eventually migrate to this area and the crispness will be lost over time.
(2) The next zone, which makes up the bulk of the cake donut, is called the baked zone. This area is very cake-like, has absorbed little fat, but has been exposed to sufficient heat for a normal leavening and the gelatinization of the starch to have taken place.
(3) The core of a cake donut, is a semi-firm, dense area which was exposed to insufficient heat with the result that incomplete leavening occurred, This unleavened dense region has a high moisture content, nearly that of the original batter. A small amount of Sodium Stearoyl Lactylate will reduce the core. Over time some of this excess moisture migrates to the surface of the cake donut, destroying the crisp nature of the crust and accelerating the breakdown of the donut coating sugar.
Trans Fat Free Cake Donuts Most donut mixes are trans fat free. The normal fat in a donut mix is straight soy bean oil. The trans fats come from the frying fat.
We can assist you with converting to trans fat free oils. Be aware that there are limitations. Generally speaking going trans fat free means converting to Palm oil based shortenings. These are not significantly healthier. The key word is significant.
Trans fatty acids occur naturally in beef, butter, milk and lamb fats and in commercially prepared, partially hydrogenated margarines and solid cooking fats. Partially hydrogenated vegetable oils were developed in part to help displace highly saturated animal and vegetable fats used in frying, baking and spreads. The main sources of trans fatty acids in the American diet today are stick margarine, shortening, commercial frying fats and high-fat baked goods.
With states now banning trans fat from restaurant use, it is only a matter of time before trans fats are an ingredient of the past. Unfortunately trans fats are being replaced with palm oil. The initial studies that compared trans fats to palm oils indicated that palm oil was slightly better. The current palm based fry fats ARE NOT native palm oil. These are fractionated oils with much higher saturated fat levels. I currently do not know of any study that has compared the nutritional value of the new palm based fry fats with the trans fat version. I expect that neither will be good for your health. Cake donuts fried in palm oil have a different flavor. I do not personally find the flavor of cake donuts fried in palm based oils to be pleasant. It is very important to evaluate the fry fat to be used After the fry fat is well broken in. Cake donuts fried in fresh fat always have a cleaner taste than cake donuts fried in older production fat.
The only choices for frying donuts at this point are:
Partially hydrogenated Vegetable oil ( contains trans fat)
Animal Fats (contain some trans fat)
Vegetable oils containing Palm oil, palm kernel oil and/or coconut oils.
As you can see, none of the choices are healthy. Many bakeries are dumping their fryers more frequently when using palm based fats. Palm based fats ARE NOT as stable.
Donuts can not be fried in canola oil, soy oil or any other liquid oils. Many articles are talking about replacing trans fats with canola oil. This can not be done. Oils that are liquid at room temperature will leach out of the donut and will make an oily mess. Solid fats are needed for sugar white and glaze stability. Cake donuts fried in liquid oils are VERY greasy and unsalable.
Esterified oils can be a good choice for cake donut frying. Be aware that some esterified oils result in cake donuts with off flavors. Test fry donuts in the esterified shortenings for several days to get some of the breakdown products and then evaluate your cake donuts over their shelf life.
Temperature Control of Cake Donuts Temperature of ingredients should be as close to 80F as Possible. Cold cake donut mix will not perform up to standards.
Temperature of water is the variable that enables the baker to reach a desired final dough temperature. Friction of Mixing is heat generated by the mixing action and must be taken into consideration when figuring final dough temperature.
It is not desirable to use water temperatures above 92F, because of the danger of leavening reaction during mixing. When such a water temperature is required, the situation can be corrected by storing the mix in a warmer environment.
Conversely, using water below 45F can cause problems as the solubility of certain ingredients is reduced, and the flour wetting for development may not take place. Water Temperature Calculation Water Temperature: 3 times the desired batter temperature minus the sum of room temperature, mix temperature, and friction input.
Example: Room Temperature = 85°F
Mix Temperature = 70°F
Desired Batter Temperature = 72°F
Friction Input Factor = 3
Water Temperature = 3 X 72 - ( 85 + 70 - 3) = 64°F Mixing of Cake Donuts Critical control points in mixing and scaling of cake donuts include:
Weight of the cake donut mix, the water and the sugar and any other ingredients. Never assume the bags are correctly weighed. Always double check as bags are often off.
Water Temperature will control the temperature of the cake donut batter.
Order of addition, water should be added to mixing bowl first, the cake donut mix should be second, and sugar should be last. This will prevent formation of dry pockets and lumping with old batter on sides and bottom of the bowl.
Degree of mixing, standard mixing times are only guidelines since the mixing time is dependent upon the configuration and RPM of the actual mixer and/or bowl used. Once optimum mixing conditions are established for each mixer, they should be posted at the mixer station. Typical mixing times are one minute at low RPM to incorporate the ingredients followed by 2-3 minutes at high speed to properly develop the batter.
Initiation of mixing, mixing should be started immediately after the addition of the mix to the bowl. Allowing mix to stand in contact with the water can result in water-leavening reactions or lumping.
Mixer and bowl conditions, minimum clearances between the paddle and bowl are necessary to minimize formations of dry pockets or lumps. Many mixers will have scrapers on the paddles. Dented bowls or dropping paddles can damage the scrapers or change the clearances. The ratio of mix size to bowl size is an important factor. In order to obtain the same degree of development when making a reduced or increased batch size, the mixing time will have to be adjusted.
The two key factors of cake donut mixing are gluten development and aeration of the dough. It is very difficult to judge the development of a cake donut as compared to yeast doughs. However, the effects of under mixing and over mixing can be seen in the finished cake donut. Under mixing cake donuts causes: Low Volume
No Star Formation
Excess cracks on crust
Poor star formation
Balling
Doughy core
Excessive spread
High fat absorption
Breakage in sugar machines Over mixing cake donuts causes Low volume
Crust cracking
Skin like crust
Peeling of crust from center
Exaggerated star formation
Uneven bloom
Hard core
Balling
Low fat absorption
Excessive dough toughness
Poor keeping qualities Floor Time of Cake Donuts This is a critical point since this allows the balance of the hydration to take place and the cake donut batter to stiffen. Normal floor times for cake donuts range from 10 to 20 minutes depending on the type of mix. This floor time is critical for consistent uniformity during the cutting of the cake donuts. Floor time will cause the cake donut batter to stiffen and the fat absorption will decrease slightly. Proper floor time will produce cake donuts that are more uniform and will have more consistent weights. However, since the cake donut batter will be stiffer, more water is required and this could affect the stability of donut sugar coatings. Old fashion cake donuts with a cracked crust should have minimal floor time.
Floor time tolerance is an important aspect to consider when selecting a cake donut mix in a commercial plant. Cake Donut Cutters Cutter overlap regulates size or weight. The overlap determines the size of the orifice through which the dough flows. The size of the opening and the pressure behind it controls the size of the donut.
Inches Pressure Cut | Inches Gravity Cut | Fried Ounces per dozen | | 1 1/4 | 1 | 4 1/2 to 6 oz | | 1 3/8 | 1 1/8 | 6 to 7 1/2 oz | | 1 1/2 | 1 1/4 | 7 1/2 to 11 OZ | | 1 3/4 | 1 1/2 | 10 to 16 oz | | 1 7/8 | 1 5/8 | 14 to 19 oz | | 2 | 1 3/4 | 19 to 22 oz | | 2 3/16 | 1 7/8 | 17 to 20 oz |
In gravity fed cake donut machines, the flow is not identical to all cutters. Weight is regulated from cutter to cutter to maintain uniformity. The cutters towards the outer ends have less overlap than the center.
The shaping of the cake donuts is controlled slightly by the overlap. Cracked topped old fashion donuts have little to no overlap. Cake Donut Frying The cake donut fryer must be set at the proper temperature, speed and fat depth.
The following changes occur during the frying of cake donuts
A. A sudden release of leavening gas as soon as the cake donut hits the fat
B. When enough gas is released, the cake donut rises to the surface of the fat. (the time from the drop to the rise is call rise time)
C. There is a rapid thickening of the cake donut batter from the setting of starch, flour and other protein coagulates providing the structure of the donut.
D. As the cake donut rises through the fat, a break appears in the surface of the dough, either at the fat level or just above it. (the time from drop to this break appearance is call break time)
E. There are projections that appear from the break in the cake donut surface reaching inward toward the center of the hole. When these projections are even (star formation), the donut is said to break evenly.
F. As the cake donut reaches the turner, the bottom crust is formed and colored. The cake donut batter is substantially coagulated except for a area of about 60 percent extending over the center of the cake donut. This is the wet bloom.
G. A cake donut should be turned just when the bubbling gases from the wet area begin to occur. after turning the wet surface, the dough undergoes the same process except no break and star from.
With varieties other than the blooming cake donut, the progression might vary slightly. Sugar Adhesion on Cake Donuts
The amount of sugar adhesion depends on the formulation of the donut sugar, the ratio of sugar to cake donuts in the sugar machine, the frying fat used, the roughness of the crust, the cake donut surface temperature, the sugar temperature, the contact time of the donut to the sugar, and the purity of the sugar.
To make the product more stable: increase cooling time, reduce water in donut, increase fry time and temperature (all of these reduces the water in the donut). In addition increase the amount of sugar adhesion so that there is more sugar (if a little melts away, there is still plenty there).
Discoloration of the sugar is caused by low fat solids. The fat melts out and discolors the sugar.
Cake Donut Trouble Shooting | Problem | Possible cause | | Low Volume cake donuts | Too little water
Over mixing
Low batter temperature
Wrong cutter size | | Cake Donuts with High fat absorption | Under mixing
Bad fat (foaming or high ffa)
Low cutter speed
Low dough temperature
Too little water |
Cake Donuts with Low fat absorption | Over mixing
Fat too fresh (low ffa)
Too much water
High dough temperature
Excessive floor time | | Cake Donuts Balling | Too little water
Too little cutter overlap
Fry temperature too low
Excessive floor time
Over mixing | | Cake Donuts with Excessive spread | Too low fry temperature
Too much cutter overlap
Too much water
Under mixing
Low fat level in fryer | | Cake Donuts with Uneven bloom | Too short cutter stroke
Over mixing
Damaged cutters | | Cake Donuts too tender | Under mixing
Fat broken down
Not enough floor time | | Cake Donuts too tough | High dough temperature
Fat too fresh
Too much water
Excessive floor time
Too fast cutter speed | | Dry Cake Donuts | Too much cooling
Too much frying
High dough temperature
Excessive floor time
Defective packaging | | Sugar white melting off cake donuts | Packed too hot
Too much water
Donuts not cooled enough | | Low sugar white pick up on cake donuts | Donuts over cooled
Need IR lights to heat donut skin before tumblers |
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