For some reason, the link to the Sarah Colombo article that I referenced in the last post does not always work. I tried to insert the link into my post as suggested by Steve (I tried a couple of ways), and had success doing so, but later it did not open up to the correct article. So I believe that the problem is at the Wayback Machine rather than on the forum. Consequently, I have decided to excerpt the part of the article that relates to dough presses. Here it is:
Hot presses work by using a manual or motor-operated heated platen to press a dough ball into a die cavity. They can create different shapes, including traditional round and rectangle crusts. Hot presses are ideal for forming oven-rising pizzas with a raised edge. Some of these presses even offer optional mold inserts that recreate the shape of hand-formed pizzas. Hot presses also have thickness adjustments so you can predetermine the exact diameter of the skin. Dan Rio, president of Dough XPress, a division of Hix Corporation in Pittsburg, Kansas, says that makes hot presses ideal for pizzerias that use conveyor ovens. "With a certain thickness setting, a 16-ounce dough ball will come out to be 14" every time," he says.
Hot presses usually require the aid of relaxing ingredients, such as oil, to help the dough stretch and to reduce shrinkage while it bakes. And because the heated platen activates the dough yeast to some degree, the dough needs to be baked immediately after it's pressed. However, most manufacturers agree that this heat exposure doesn't critically affect the structure of the dough. "People are under the assumption that the heated platen cooks the dough, but it doesn't," explains Dale LaRose, sales manager of Cuppone America, a division of Global Industries in Manteca, California. "When you press dough, it brings the gluten gel to the surface, seals that formed pizza base, and holds the steam center inside when it bakes." Like sheeters, hot presses come in different sizes to accommodate various production levels at pizzerias. Although most presses can't accommodate the volume typically produced by sheeters, they're generally less labor-intensive to operate. "There is very little employee training involved with a press, because all they need to know how to do is press a button," says Larry Serafin, marketing manager for the Dolton, Illinois-based AM Manufacturing Company.
Cold presses, which are popular in high-production markets, perform a similar function to hot presses, except they don't rely on heat activation. Instead, they form using a high water-absorption process and dough set to a high temperature (generally around 100°F). Cold presses require that the dough is very soft to form, which can make it difficult to create a welldefined, raised-edge crust. However, they also afford a unique opportunity by allowing you to finish forming the dough by hand. Like hot presses, cold presses rely on oil or similar activating ingredients. Cold presses are also ideal for making focaccia bread, and can produce unique, fried-bottom crust pizzas.