A tomato machine is a device used to process tomatoes, turning them into juice, paste or pulp. There are a variety of designs, some made for use on a countertop in the home and others specifically built for use in a commercial or industrial environment. Features can vary from one tomato machine to the next, but they generally include the ability to remove the skin and seeds from tomatoes while they are being mashed or pressed. Both electric and manual models exist, with electric versions being able to process several bushels of tomatoes in an hour. The concept of a tomato machine is fairly simple, so some devices actually have a collection of modular attachments that can allow the machine to be quickly converted into anything from a meat grinder to a juicer.
The basic components of a tomato machine include a large hopper on the top that tapers down into a thinner channel leading to the area where the tomatoes are pressed. This area usually contains a set of paddles that might be spring loaded, as well as some type of sharp metal device that performs the actual processing of the tomatoes. A chute leads from this area under the hopper, allowing the juice that comes out of the tomatoes to be directed into a specific container or area, although some models have more than one exit chute to allow the different parts of the separated tomato to be divided. The machine also can have a clamp or suction cup that can stabilize it on a countertop, although large commercial machines and some electric models rely more on their weight for stability.
Inside a tomato machine, processing can be performed by an auger, a screen or a cylindrical grater. An auger looks like an exaggerated screw with deep grooves. The tomatoes are pushed into the auger and the skin, which is thick and waxy, gets separated from the flesh and juice through pressure. A metal screen separates skins and seeds from the juice by acting like a strainer as the tomatoes are pressed against the screen by strong paddles. A cylindrical grater often has sharp, small holes punctured around the exterior that shred tomatoes as they are pressed into it, allowing the juice and pulp to exit the machine down the center of the cylinder.
Plastic, stainless steel and cast iron can all be used to make the various parts of a tomato machine. Stainless steel is seen most often because of its resistance to staining, which can be caused by tomatoes. Cast iron can be used to make the base for the machine, the handle or other elements that need to be heavy and durable.