This process can either be done by hand or through the use of machinery such as high-pressure sprayers. With the use of a conveyor belt, the food is moved along under a high-pressure sprayer to remove the debris listed above. Another method that may be used by companies is the use of a hollow drum which circulates the food while water is sprayed onto it to remove the debris. Next, a steam-heated mixer is used to cook the grain and remove any extra debris and excess water. The mixer typically has oils within it (such as safflower oil). As the oil simmers, the grains are gradually added in and the blades are used to mix the grains around. The steam created in the mixer allows the grains to cook resulting in a puree. Next the vegetables are cut up into smaller pieces to allow more surface area for cooking purposes. This can be done by hand or through the use of machines in factories. The vegetables are then added to the grain mixture in the steam-heated mixture. The exact ratio of grains to vegetables is unique to each company, resulting in different textures and tastes that are produced. As the vegetables are being cooked in the mixer, their natural sugars release, resulting in caramelization. The sweet flavors thus created from this caramelization are mixed uniformly in the mixer. The technique used for the creation of this caramelization mixture is called mirepoix. This technique is very important to the production of veggie burgers, as it adds both texture and flavor to the patty. The mirepoix mixture is then placed into another mixing tub, where dry ingredients such as oats, walnuts, potato flakes, and more are added. The mixture is then folded together to make a uniform mix. The moisture from the vegetables causes the mixture to become sticky, thus clumping together like cookie dough. This is important, as it allows the veggie burger to stick together to form the patty. The mixture is now put into an automatic patty-making machine or press. The press then punches out the patties into a disc shape onto a conveyor belt underneath. A constant spray of water may also be used to prevent any of the mixture from sticking to machinery parts. Once on the conveyor tray, the patties move along to be put onto baking trays. Patties are first inspected to make sure they are the correct shape, size, and texture to ensure a high-quality product. The trays are then put into a heated convection oven at a designated temperature and time.