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 frozen pizza crust is mechanically formed. 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, and after several stretches, the thin skin is pressed into thin slices of about 0.32 cm to 0.64 cm, and the thick skin is stretched to 0.64 cm or more to 0.95 cm, and then cut into circles or other shapes, and 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 for 1 2 times to make the cake crust and baking tray have the same diameter. The dough will not shrink after being pressed twice, 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 needed to press and cut the shell. In addition, the dough formed by compression needs to be softer than the dough cut by extrusion, so it is easy to be formed by 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 will be 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, so as 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 the thickness of the crust. If the crust of the cake, such as handmade pizza, requires a protruding edge, it can be made with a special hot-pressing mold; As for expanding the edge of cake crust by extending cutting, it is labor-consuming and the expanding effect is poor.
Many frozen pizza manufacturers will add 10% polyester corn grits to the thin pizza crust, or add 20% corn grits to the bottom of the thick pizza crust, so that when the conveyor belt is removed, the crust is simple and non-sticky and 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 generally uses flour with high protein content (1 1.5% to 14%), because high protein content can make gluten complete, and the sauce will continue to wet the crust and the crust will become brittle. Although flour with high content in protein can also be used to make thick skin, the dough made from flour with low content in protein will not shrink, and the skin will be 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 bite force of thin-crust pizza. Usually, low-protein flour is added with 1% to 2% of active gluten 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% salt, while thick-skinned pizza may add 1.5 to 2.0% 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 you don't add yeast (or a small amount) to make spontaneous frozen pizza, you can use glucose, high fructose corn syrup, honey and other reducing sugars to get a good baked skin color.
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 die usually contains more oil than thick crust and extruded dough. Insufficient oil consumption will make the dough sticky, poor fluidity and uneven molding, and the moisture in the sauce will easily spread to the dough and make it moist. The amount of oil added is generally 3% ~ 15% of flour. If pizza needs to be frozen for a long time, 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 the frozen pizza of breakfast food is to be developed, it is more appropriate to use the swelling acid of sodium aluminum phosphate to produce biscuit flavor, and if the frozen pizza with dim sum flavor is to be developed, 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. It means that 1 pound of baking soda needs 1 pound of sodium aluminum phosphate and gluconic acid. Lactone needs 2.2 pounds. Is sodium aluminum phosphate more than gluconic acid? Lactone is cheap, the dosage is small, and sodium aluminum phosphate is more economical. However, the amount of swelling acid only accounts for 0.5% to 2% of the flour, which accounts for very little cost. Therefore, it is necessary to compare the product quality after actual trial and then choose the appropriate swelling acid.
Expansion alkali: both sodium bicarbonate (baking soda) and potassium bicarbonate can be used as expansion alkali for dough. Potassium bicarbonate can be used to reduce the content of sodium ions in dough, 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 cold storage, which will cause 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, before adding the dough, it is best to keep the temperature in the range of 3℃ to 7℃. Too high or too low temperature will reduce the activity of yeast.
Water: The amount of water added is very important to the characteristics of dough. Too much moisture will make the dough too soft and sticky, and the mechanical operability is poor, and it may flow through the grill when baking; However, when the water absorption is insufficient, the dough has poor fluidity, but it can't make the crust expand to the required height and volume, resulting in the crust taste as tough as leather shoes. The best way is to add 50% water first, and then make a small adjustment. Most of the water added is between 48% and 54%, depending on the water absorption rate 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, which is the weight of flour, while it is 45-60ppm when it is molded with a mold. Excessive reducing agent will soften the dough during baking and flow through the grill, resulting in 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. Stearic acid tablets can remain intact after being mixed with dough, and only melt and flow out when baking, resulting in cracks in the skin.
Frozen storage and packaging of pizza
Usually, the dough is frozen immediately after crust formation 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, and then frozen 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 generally completed within 15 minutes 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). If the dough is not completely stirred, the mechanical operability is better, and the crust will not be too strong after baking. If it is stirred too much, the dough will become soft and poorly formed, and the baked pizza will be small, too tough and have a bad taste.
If the skin is molded by a mold and the dough is soft, 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. Generally, the 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 bubbly, resulting in poor forming.
Usually, dough that is swollen by chemical methods does not need any steps. The traditional preparation method is to mix all the dry materials while stirring, then add water containing yeast into the dry materials and stir for 2 minutes at low speed, add oil and continue stirring for 4 minutes, and then stir for 2 minutes at medium speed until the dough is unified into dough. After being divided into small dough, if yeast is added, it can be fermented for 10 to 20 minutes, and then shaped manually or mechanically. In automatic production, dough is extruded into dough, and then cut or hot pressed. The molded skin can be slightly proofed for 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 with sauce and stuffing, and then returned to the freezer for frozen packaging.
Generally speaking, tunnel ovens are used to bake pizza. The inlet temperature was 204℃, the outlet temperature was 3 15℃, and the baking time was about 3 to 5 minutes. Generally, frozen pizza is baked directly from the freezer. Pizza can be placed on the top of the 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 baked directly at a temperature of 204℃ to 232℃, depending on the product design.
The chemical expansion festival of pizza saves fermentation time and allows busy people to taste delicious food quickly, which is also 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, which changed with the change of chemical leavening agent. Many advantages make the prospect of chemical expansion of pizza crust promising.