warranty than mild steel fryers. Some commercial fryers have a "cold zone" at the bottom of the fry pot. This is where food particles, such as breading, batter or broken off pieces of food, sink to, while the lower temperature keeps them from burning and tainting the oil. A tube-style fry pot has a large cold zone because the tubes are slightly above the bottom of the vat, leaving generous space for cooler oil and crumbs. This is particularly useful for cooking heavily breaded foods (such as a blooming onion). A tube-style fry pot is more difficult to clean than an open fry pot, but the tubes allow easy access to the heat source. Tube fryers are often less expensive than their open fry pot counterparts. Open fry pots have an external heat source, which makes them easier to clean and affords better access to the oil, but they generally offer a smaller cold zone, so food particles could pollute the flavor of the oil. However, these fryers work very well for lightly breaded foods. Flat-bottomed restaurant fryers (another type of open fry pot fryer) can also be difficult to clean and have no cold zone, but they are highly effective for frying dough. Flat-bottom fryer pots may also be used with a batter trapping insert that keeps loose batter from quickly scorching on the bottom where the heat is applied normally. A batter trap can also help keep loose batter from being stirred up in the oil and adhering to subsequent batches of food in order to make foods taste better and extend the cooking oil's usability. Some domestic fryers incorporate an angled motorized rotary basket that circulates its contents through the hot oil. This design reduces the amount of oil required to roughly half compared to a more traditionally designed fryer. Domestic fryers are generally much smaller than their commercial counterparts and typically have a capacity of two to four liters. Temperature controls Temperature controls for deep fryers can be implemented, but are uncommon. Without them the deep fryer needs to be watched consistently to ensure safety. There sometimes are "computerized temperature controls" in fryers on the market today, especially in commercial fryers. In fact, some modern fryers have an automatic shutoff control, just in case the temperature gets too high, which adds another level of sophistication and safety. It is a good idea to use a separate