Pizza crust can generally be divided into thick slices and thin slices. Thick crust such as bread and thin crust such as soda crackers have different tastes and formula requirements. No matter how thick the crust is, the crust of frozen pizza is formed by machinery. Mechanical forming can also be divided into methods of stretching and cutting into blocks and methods of pressing dough into flat disks or other shapes.

1. Pressing and cutting

First, roll out the dough. After several stretches, the thin crust is pressed into thin slices of about 0.32 cm to 0.64 cm, while the thick crust is stretched to 0.64 cm or more to 0.95 cm, and then cut into circles or other shapes. The remaining dough can be recycled.

2. Molding

In the traditional molding method, the stirred dough needs to be slightly proofed and divided, then proofed for 5 to 10 minutes, and then pressed 1 2 times to make the cake crust and baking tray have the same diameter. The dough will not shrink after two presses, and it is best to relax for 2 to 3 minutes. Before baking, punch holes in the crust with a blunt needle to avoid foaming on the surface during baking. This step is also required for housings made by pressing and dicing. In addition, the dough formed by compression needs to be softer than the dough cut by extrusion, so it is easy to form during compression molding.

The temperature of the mold is also a manufacturing condition that must be paid attention to. The dough of frozen pizza baked by consumers is usually made by (hot pressing) or (delayed cutting). However, when consumers buy baked products, it is more appropriate to use cold pressing molding. When hot pressing is used, the temperature and time of the mold should be reduced to avoid overheating to complete the reaction of swelling agent. Generally, the mold temperature is set to 190℃ to 2 18℃, and the bottom baking tray temperature is set to 177℃ to 204℃ for 4-6 seconds, which can be changed according to the dough composition and cake crust thickness. If the shell of the cake (such as handmade pizza) needs to have a protruding edge, it can be made by using a special hot-pressing mold; As for bulging the edge of the cake crust by extending the cutting, it is more labor-intensive and the bulging effect is poor.

Many frozen pizza manufacturers will add 10% polyester corn cob to the thin pizza crust, or add 20% corn cob to the bottom of the thick pizza crust, so that when the conveyor belt is removed, the crust is simple and non-sticky, and the crust feels more brittle. The most important thing is to create the texture of handmade pizza, which is more popular with consumers.

Emphasize the use of raw materials

Flour: Generally, the whole flour or refined flour mixed with hard red winter wheat and hard red spring wheat is used, with protein content of11.7-12.8% and ash content of 0.45-0.475%. You can use cooked flour with barley malt or nutrients added.

Thin-crust pizza usually uses flour with high protein content (1 1.5% to 14%), because high protein content can make gluten complete, the sauce will continue to wet the crust, and the crust will become brittle. Although flour with high protein content can also be used to make thick skin, dough made with flour with low protein content will not shrink, and the skin is chewy but not too tough.

Adding active gluten can make up for the difference of flour specifications, so that thin-crust pizza and thick-crust pizza can use the same raw materials, prevent the transfer of sauce moisture, and maintain a certain taste of thin-crust pizza. Usually, 1% to 2% of active gluten is added to low protein powder to make thin-skinned pizza. Every addition of 1% can increase the protein content of flour by about 0.6%.

Salt: Traditional thin-skinned pizza usually only adds 1.0% to 1.5% of salt, while thick-skinned pizza may add 1.5% to 2.0% of salt to enhance flavor. Because chemical expansion method will produce salt, the dosage will be less than that of traditional yeast expansion method.

Sugar: Sugar can be used as a nutrient for yeast fermentation, and it can also deepen the color of baked cake crust. If your spontaneous frozen pizza does not contain yeast (or a small amount), you can use reducing sugar, such as glucose or high fructose corn syrup and honey, and you can get a good color of scones.

Oil: Because the chemically expanded pizza crust lacks fermented flavor, it is very important to choose the type of oil for the flavor of the final crust. Olive oil is usually the most commonly used. Because of its good flavor but high price, in order to reduce the cost, only 10% to 20% olive oil is usually used, and other oils are mixed. Pizza crust made of thin crust or compression mold usually contains more oil than thick crust and extrusion cut dough. Insufficient oil consumption will make dough sticky, poor fluidity and uneven molding, and the moisture of sauce will easily spread to the crust and make it wet. The amount of oil added is generally 3% to 15% of flour. If pizza needs to be frozen for a long time, we should consider using corn oil, soybean oil or olive oil which is not easy to oxidize and has high stability.

Expansive acid: sodium aluminum phosphate and gluconic acid? The swelling effect of lactone is similar, but the final product has different flavor, neutralization value and price. The shell of sodium aluminum phosphate smells like biscuits, but gluconic acid? Lactones are sweet, so it is necessary to understand the differences when developing new products. If you want to develop frozen pizza for breakfast food, it is more suitable to use the swelling acid of sodium aluminum phosphate to produce biscuit flavor, and if you want to develop frozen pizza with dim sum flavor, it is better to use gluconic acid. Lactones are more suitable. Generally speaking, sodium aluminum phosphate is still the most commonly used swelling acid.

Sodium aluminum phosphate and gluconic acid? The neutralization values of lactone are 100 and 45, respectively. This means that 1 pound of baking soda requires 1 pound of sodium aluminum phosphate and gluconic acid. Lactone needs to use 2.2 pounds. Is sodium aluminum phosphate more than gluconic acid? Lactone is cheap, the dosage is small, and it is more economical to use sodium aluminum phosphate. However, the amount of puffed acid only accounts for 0.5% to 2% of flour, which accounts for a small proportion in the cost. Therefore, we should still compare the product quality after the actual trial, and then choose the appropriate puffed acid.

Expansion alkali: Both sodium bicarbonate (baking soda) and potassium bicarbonate can be used as expansion alkali for dough. When the content of sodium ion in dough is to be reduced, potassium bicarbonate can be used, but sodium bicarbonate is still the most commonly used swelling alkali.

Yeast: Fresh concentrated yeast is usually used, because the gluten produced by the death of dry yeast will weaken during refrigeration, and there are many problems in use. Generally, the dosage of yeast is 0.25-2%, and most formulas use 0.25-0.75% concentrated yeast. Fresh yeast has a short shelf life, so it is recommended to buy it in small quantities for many times. It is also necessary to pay attention to the conditions of yeast transportation and storage. For example, it is best to keep the temperature in the range of 3℃ to 7℃ until it is added to the dough. Too high or too low temperature will reduce yeast activity.

Water: the amount of water added is very important to the characteristics of dough. Too much water will make the dough too soft and sticky, and the mechanical operability is poor, which may flow through the grill during baking; However, when the water absorption rate is insufficient, the fluidity of the dough is poor, but it can't make the cake crust expand to the required height and volume, resulting in the tough taste of the cake crust like leather shoes. The best way is to add 50% water first, and then make a small adjustment. The amount of most water added is between 48% and 54%, which depends on the water absorption and formula of flour.

Reducing agent: L- cysteine or glutathione produced by dead yeast is most commonly used as reducing agent for pizza crust. They can reduce the tension of dough, shorten the stirring time, and prevent the formed skin from foaming or peeling. The addition amount of reducing agent is 10-25ppm based on the weight of flour, while it is 45-60ppm when it is molded by mold. Excessive reducing agent will soften the dough and flow through the grill during baking, which will lead to poor pizza quality.

Stearic acid tablets: Stearic acid tablets are not often used, but sometimes adding 8% to 12% stearic acid tablets to the dough can make the pores inside the pizza crust more uniform. When the dough is added and stirred, the stearic acid tablets can still remain intact, and only when baked will they melt and flow out, resulting in gaps in the shell.

Frozen storage and packaging of pizza

Usually, the dough is frozen immediately after the dough is formed to make it hard, then the sauce and stuffing are added, then the dough is frozen for the second time, taken out and padded, then heat-shrinkable packaged with polyethylene or polyvinyl chloride, then frozen and stored for at least 48 hours before distribution and transportation. The frozen state stored at 23℃ can last for 4 to 6 months, and only the frozen pizza crust can be stored at 2 1℃. If there are vegetables in the stuffing, it is necessary to freeze the pizza with cold air at 29℃ to 32℃ or with refrigerant at 40℃ to 62℃ to avoid the separation of sauce and vegetable stuffing during thawing or baking.

Homemade pizza crust

The mixing step of raw materials is usually completed within 15 minutes, so as to avoid the dough temperature rising, stickiness and uneven bubbles caused by long mixing time. If it is extrusion molding, it is usually stirred for 3 to 5 minutes to form a block (it can be stirred for a while). The dough that is not completely stirred has better mechanical operability, and the crust will not be too strong after baking. If you stir too much, the dough will become soft and poorly formed, and the baked pizza will be small, too hard and have a bad taste.

If the crust is molded by a mold, the dough should be soft, and a small amount of oil can be added 5 to 10 seconds before the mixing is completed, so that the dough can be easily taken out of the mixing tank. Usually, spontaneous pizza dough using chemical leavening agent does not undergo fermentation or proofing, but sometimes it can be proofed for 10 to 15 minutes after stirring, but if the proofing time is too long, the dough will become sticky and foaming, resulting in poor molding.

Usually, dough that is chemically expanded does not require any steps. The traditional preparation method is to mix all the dry materials while stirring, then add water containing yeast to the dry materials and stir at low speed for 2 minutes, add oil and continue stirring for 4 minutes, and then stir at medium speed for 2 minutes until the dough is combined into dough. After being divided into small dough, if yeast is added, it can be fermented for 20 minutes, and then shaped by hand or machinery. In automatic production, dough is extruded into dough and then cut, or formed by hot pressing. The formed crust can be slightly proofed 15 minutes to make its structure more complete and have the special flavor of fermentation, and then frozen to make it hard and easy to handle.

The frozen cake shoes are sent to the final processing area to add sauces and fillings, and then returned to the freezer for frozen packaging.

Generally speaking, tunnel ovens are used to bake pizza. The inlet temperature is 204℃, the outlet temperature is 3 15℃, and the baking time is about 3 to 5 minutes. Generally speaking, frozen pizza is baked directly from the refrigerator. Pizza can be placed on top of an oven without a baking tray, or it must be placed on a baking tray. Some even need to preheat the baking tray, but some ovens can be placed directly in a cold place and set the temperature to 204℃ to 232℃ for direct baking, depending on the product design.

The chemical expansion festival of pizza saves fermentation time and enables busy people to taste delicious food quickly, which is the main reason for its popularity. However, in the past, yeast dough had to be fermented at 20 or 30 degrees, and producers had to work in a hot environment. This situation changed with the switch to chemical leavening agents. Many advantages make the chemical expansion of pizza crust promising.