The first and primary consideration in the evaluation of a yeast-raised donut is customer acceptance, which is seen by repurchases. A yeast-raised product should have, apart from being a wholesome product, a number of characteristics :

Let's first have a look at the different kind of donuts using the following overview:

1. Recipe and raw materials

Our topic will be the yeast raised table-cut donut. This area covers rings, which are conventional donuts with a hole in the middle, shells, which are round and usually filled, long johns, also normally filled but cylindrical in shape, and twists, made by braiding or twisting together one or two pieces of dough. When considering what we want in a finished product, we must look at the basic formulation and the ingredients. First we must consider the flour. Too often this ingredient is not taken into consideration, in spite of the importance that it commands, since at times, one flour might not be correct for a specific formulation. I will briefly set a few basic guidelines for the flours.

Good quality wheat flour is most essential for yeast raised table cut donuts. It should have a protein content of 11.5 to 13.5 percent. Soft wheat flours (cake or pastry types) can be used for pressure cut cake donuts. Secondary flour materials that influence formulations include soy flour, corn flour and potato flour.

bakers percentage
ingredient
100 %
flour
5 - 14 %
sugar
8 - 10 %
shortening
9 - 15 %
skimmed milk powder
0 - 3 %
soy flour
1 - 2 %
salt
2 - 5 %
liquid whole egg
0 - 1,5 %
baking powder
4 - 7 %
yeast
0,5 - 1 %
emulsifier type ssl
55 - 60 %
water

Sugars are generally a combination of sucrose and dextrose. Sucrose contributes sweetness, tenderness, crust colour and food for the yeast. Dextrose caramelises at a lower temperature (155C, compared to 160C for sucrose), which makes it particularly suitable for controlling crust colour. Excessive use of sugar yields greater caramelisation in the frying kettle and can cause excessive shortening absorption and below average volume.

The function of shortening and emulsifiers is tenderness, eating quality and shelf life. They are also used to lubricate the dough system during fermentation. Emulsifiers vary in use level depending on the type. Excessive shortening absorption and gumminess may result from the use of too much of these ingredients.

Non-fat dry milk buffers fermentation, contributes to keeping quality because of its moisture-retaining abilities, improves crust colour due to the lactose and contributes to flavour. Soy flour improves water absorption and keeping quality. Excessive amounts of soy flour can have a weakening effect on the gluten, causing open grain and a dark crust colour. High fat soy flour contains lecithin, which has the unique property of attaching itself to both oil and water and which, therefore, is an excellent emulsifying agent.

Salt is used for flavour and acts as a "policeman" in the dough fermentation. Salt also affects mixing development and contributes to gluten strength during the proofing period. Insufficient salt produces doughs of low tolerance and poor flavour.

Whole eggs and egg yolks tenderise, yet reduce the tendency toward collapse of the white ring at the fryer turner. Eggs also improve eating quality, crust colour and shelf life.

You might be surprised by the presence of leavening agents but they tenderise and benefit fermentation and the handling of the dough at make-up. I prefer to keep the yeast on the lower side for the better sheeting and handling of doughs. Excessive uses of yeast to hurry the doughs along only causes gassiness, less tolerance to proofing and sometimes collapse when the donuts are removed from the fryer. It is not uncommon to use for donuts a combination of baking powder and yeast.

Don't use too much water in the dough. Doughs should be firm out of the mixer. Insufficient water makes for poor expansion and shelf life, but worse, too much, yields slack doughs, which cause too much spread, gassy doughs, blisters, and a lack of uniformity in size and shapes of the finished products. Over-proofing can also be the fault of slack dough.

One ingredient, which is not mentioned in the recipe is sourdough. Sourdough gives extra strength to the dough. The donut will have an excellent flavour and a nice white ring. I have done experiments myself with sourdough and I can guarantee that the resulting product is of a superior quality. On top of that one can easily make some kind of sourdough from the left over cuttings especially in the case of table cut donuts where the scrap can be more than 50 %. I strongly suggest, for uniform production, the scraps be weighed, so that equal amounts go into each dough and an equal fermentation cycle can be established otherwise, doughs and products will vary in their fermentation and proofing times. Doughs containing in excess of 20 percent scrap should also be kept somewhat cooler (25C). Scrap-sourdough should be added during the last seven or eight minutes of mixing to prevent over-development of the scrap gluten - which really has been mixed once already.

The best yeast-raised fried bakery foods are produced from firm, well-developed doughs. Properly developed doughs make for uniform, smooth and elastic sheeting on make-up tables and also, like bread, improve grain and texture along with eating quality and shelf life of the fried products.

2. Technology

"Well developed" generally means mixing to clean-up plus two to four minutes, depending on the strength of the flour used in the formula. Properly mixed doughs cause less sticking and hang-up on donut cutters, help the donuts retain the proper shape when being transferred to cloths, screens or directly onto proofer trays, and require less dusting flour. Under-development of these same doughs causes buckiness and the tendency to tear on sheeting rollers.

Mixing times may vary because of the protein strength of the flour used, speed of the mixer and the batch size. The same principles apply as for bread (see the chapter on mixing Bakery technology - Mixing).

Dough temperatures should be 25 to 28F. This depends on the temperature in the bakery and the percentage of scrap being added back (if you transformed the scrap into sourdough it can mature at low temperature). When generous amounts of scrap are added, doughs should be kept on the cooler side. Doughs that are mixed too cold, ferment too slowly and will produce young products. Such dough will have a coarse, open grain and texture, and donuts will tend to blister on frying. The opposite effect is seen with warm doughs, which ferment too rapidly and tend to become gassy. As all of you bakers know, this causes nothing but problems, such as difficulty in proper sheeting, a lack of tolerance in proof box and crippled donuts which absorb too much frying oil.

Make-up speed is naturally governed by fryer capacity. For a uniform flow of product, whether producing 1500 pieces or 15.000 pieces per hour, the make-up station should not exceed the fryer's capacity, or over-proofed donuts will result.

Careful sheeting is a must for the best possible uniformity of product size and weights. Modern equipment will sheet the dough in 2 or 3 steps with a pre-sheeting station before the dough goes into the first set of head rolls. Too many bakers attempt to sheet dough on head rolls that are just too small - only to suffer variations in size and weight. This lack of pre-sheeting also contributes to excessive scrap because the too large and too small units are allowed to go over the end of the table only to be reprocessed again.

Dough sheeting

Dough sheeting

Particular attention should be paid to the tension of the dough out of the head rolls and onto the moving belt. When tension here is too tight or some stretch is noticed, donuts draw up and are misshapen before transferring onto the proofing screens. When the dough is too thick going into the cutters, it will hang up, with cripples and more scrap resulting. Attention should be paid to the use of proper sized cutters for the specific weight of donuts desired.

Cutting

There has been much talk on the pros and cons of round versus hexagonal cutters. Depending on surface area, both are used successfully. A round cutter averages about 60 percent donut and 40 percent scrap. By comparison a hexagonal cutter produces approximately 80 percent donut and 20 percent scrap. The exact ratio is controlled by the amount of side trim and the size of the cutter used. The most popular sizes of cutters are the 7 cm and 7,5 cm sizes. It is not recommended that a 7,5 cm hexagonal and a 7,5 cm round cutter be used for the same size donut. In other words, the hexagonal and round cutters of equal measurement are not interchangeable.

Although you can get cutters with centre holes of various sizes, both the 7 and 7,5 cm cutters, have a standard 2,85 cm hole. The hole alone produces 16.7 percent scrap for a 7 cm cutter. On a 7,5 cm cutter, the hole alone produces 12.75 percent scrap. Therefore, erratic control of the side trim is where most scrap occurs over these figures. The scrap produced by the holes is inherent to the process and as a consequence the scrap cannot be reduced.

Yeast-raised fried products are most often proofed at 32°C to 35°C - with a wet bulb temperature of 30 to 35°C. Proof times are usually 30 to 35 minutes, but can be up to 40 to 45 minutes. Under no conditions should the donuts be allowed to become wet in the proof box. A wet box causes blisters, high shortening absorption and excessive spread during proofing. The newer, automatic proofers with zone controls permit adjustment of proofing conditions in different sections or zones of the box. Automatic proofers employ a moist zone at the beginning of proofing to improve the spread of the donuts and a drying zone toward the end for rise and volume, plus release characteristics off the trays into the fryer. Whatever the case, good maintenance of proof boxes is essential for day-in, day-out uniformity.

After proofing

Under-proofed donuts most often blister, and will have a much tighter grain and texture. When this blistering problem is observed, a few additional minutes of proofing time will correct the problem. It has been my experience that low yeast levels, with a longer, more gradual proofing time (of up to 40 minutes or so) and a full proof, help to eliminate blistering problems. Over-proofing of donuts, on the other hand, can also cause blisters, as well as a coarse, open grain, poor shape, excessive frying shortening absorption and collapse at the glazer.

A temperature range of 190 to 200C is used for frying. Personally, I like the higher temperatures and find that they seem to result in better jump or expansion in the kettle. The average frying time for 18 to 19 ounces per dozen, unfried weight is 110 to 120 seconds or approximately one minute on each side. Often, settling or collapsing of the white ring is due to a frying time, which is too short. Frying times can vary due to the weight of the products; naturally larger or jumbo sizes should take longer to fry. Frying times should be checked often, and kept to an exacting period. The longer the donuts are unnecessarily kept in the fryer, the more it costs' in extra shortening absorption. Some shops use checklists prior to production, involving stopwatches and thermometers, to be sure of turner speeds and proper frying temperatures.

Frying at too low a temperature invites a slower colouring or browning of the crust and allows excessive shortening to penetrate the skin before the donut is finished frying. Frying at too high a temperature has the opposite effect, browning the crust too rapidly and not allowing the product to expand sufficiently in the allotted time sequence thereby cutting down on the over-all volume. Frying time also affects crust colour, volume and shortening absorption and, together with frying temperature, plays a big part in the formation of the finished donuts.

Production schedules should be arranged so that the frying kettle does not stand empty for extended periods of time. Allowing the shortening to stand idle at high, frying temperatures will cause rapid deterioration of the frying shortening and development of a high free-fatty-acid content, causing the shortening to break down.

Shortening absorption for a 50 g donut (unfried weight) is between 8 and 10 g a piece. This varies somewhat due to the richness of the formula being used. A richer formula generally absorbs more shortening.

Glazing is another aspect of donut production that is not without its problems. On top of that some of these problems seem to appear unexpected with no reason at all only to disappear again without any explanation. Perhaps the following considerations will help to explain the unexplainable.

To begin with, properly glazed donuts are cooled for one to 1.5 minutes out of the fryer before glazing. This time allows the excess frying shortening to run off the crust and allows the product to cool or "set" slightly before the glaze is applied. The temperature of the glaze should be 43 to 48C, at the time of application. The reason for this is that the crust temperature and glaze temperature are compatible for best coverage and adhesion. You can in no way get good glaze results with cold donuts and hot glaze, or hot donuts and cold glaze.

The glaze should be cooked and should contain some granulated sugar-especially for those of you who wrap your products. The granulated sugar level can range from 10 to 35 percent of the total amount of sugar used in the formula. The moisture content of the glaze should be kept as low as possible, usually 22 to 24 percent based on total sugar.

The glaze should not be thinned with anything but simple syrup. Simple syrup is two parts sugar and one part water, brought to a boil! Too many bakers thin glaze with water alone. This causes rapid deterioration of glaze stability and results in weeping or sweating. The use of one to two percent hard fat flakes with a melting point of 55 to 60C, based on sugar weight, will help prevent weeping and sweating of glazed donuts.

Adding about 3 % of trealose to the icing, will increase the stability of the icing.

Often in winter months, when the humidity is low, glaze-chipping problems are experienced. The addition of invert or corn syrup to the formula at as high as eight percent based on sugar, will often correct this problem. Excessive amounts of these hygroscopic syrups can interfere with sucrose crystallization, which is the reason glaze sets up in the first place. When used, the invert or corn syrup should be boiled in the first stage, along with the granulated sugar.

cooling of donuts

Last but not least, proper cooling after glazing is important and is shown in the above picture. Donuts should not be packaged or boxed before they have reached room temperature.

Sugaring donuts with granulated or a powdered sugar preparation is very common and also fraught with many problems. Dextrose is used primarily because it lends itself to longer stability as a donut coating than does sucrose. Certain sugar preparations are specifically formulated by the manufacturers for long shelf life on donuts. It must be understood, however, that this is basically an unstable system. Sugar, even dextrose, is soluble. donuts contain moisture and it will migrate from the donuts to the coating and dissolve the coating if it contains soluble materials. The disappearing act of the sugar depends also on the temperature of the crumb and the crust. If the crumb is still warm, moisture will migrate to the crust and will dissolve the sugar. It is better to cool down the donuts completely and then slightly heat the surface up again by means of infra-red radiation for instance. This will result in a lower moisture transfer rate from the crumb to surface and, therefore, a lower rate of solubility of the coating material



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