Although devices to deep fry foods are very common, they have few basic design changes since their inception. Generally these machines in simplest terms have a pot containing enough oil to fully immerse foods to be fried, along with a heat source to bring the oil to frying temperature.
What is known today in the art of home use deep fat fryers are small countertop devices. Such home use countertop devices have a very limited capacity, such as the ability to cook only a few ounces of French fries or the like in up to about 8 quarts of cooking oil. Besides lacking capacity, such conventional devices are inconvenient to use. Typically, a user must first pour cooking oil into the device and preheat the cooking oil before cooking can commence. Preheating the oil can take from a few minutes to more than half-an-hour, after which time the user must then return to immerse the food into the hot oil. If the user returns too soon, the oil is not fully heated, resulting further waiting by the user before using the device.
After oil preheating, the food must be immersed into the oil. Immersing food into the extremely hot cooking oil can be a dangerous process. For example, a user might be holding onto a short handle just a few inches away from the exposed surface of the hot cooking oil while trying to gently lower a basket full of food at the end of the handle. Upon placing the basket and the food contents into the hot oil, the oil can erupt with boiling, and/or sputtering that could burn the user, and that could possibly result in the basket being dropped and splashing into the hot oil should the user become burned during the process and let go of the basket to avoid further harm. Dropping the basket into the hot oil, however, could result in a more violet result that could cause further harm to the user. In many devices, the surface of the hot cooking oil may be fully exposed when the food is being lowered into the oil, thus presenting other safety hazards of accidental contact with the extremely hot oil.
Once the desired food content is immersed in the hot oil, the cooking process can take anywhere from a few minutes to more than an hour. At the end of the cooking process, the user must be present at a precise time to remove the food from the hot cooking oil. If the user arrives too late, the food may be overcooked. If the user arrived too soon, they may have to wait until the food is fully cooked, or have undercooked food.
Next, drainage of the oil from the food is required. This again can take anywhere from a few minutes to over half-an-hour. After the food has been drained, the user must again return to serve the food.
Deep frying in these devices whole pieces of food which cannot be subdivided has several disadvantages. First, there must be sufficient oil heated in the oil containing cooking pot to fully immerse and fry the non-dividable food to be cooked. Cooking oil can be expensive and difficult to dispose of. Common deep fryers, by fully immersing the food they fry, generally use substantial quantities of cooking oil.
Hot cooking oil can also present substantial safety hazards, both from the dangers of the hot oil being spilled, and from the danger of sputtering and splattering of hot oil. There is also the danger of food being accidentally lowered too quickly or dropped into the hot oil causing splashing and spraying of hot oil. Generally, the more oil there is, the more danger.
The cooking oil that is used in such conventional countertop devices may only last for one to about four uses, after which the oil must be changed. Filtering the cooking oil between uses generally helps to increase its useful life. While some commercial units have pumps and filters to periodically cleanse their cooking oil during and/or between uses, such countertop home units generally have no means for such oil filtration. Thus, the cooking oil in these devices must either be changed as noted above, or filtered by a manual method that involves a multi-step task of physically removing the oil from the device, filtering it outside of the device, and then reintroducing the oil into the device.
The oil from such countertop device is removed by pouring the oil from the device into a disposal container, and then discarding the oil by pouring it down the kitchen drain. The practice of discarding used oil down the drain may clog the drain pipes. Disposing of used oil is generally also a cumbersome process, as the heavy, greasy, oil must be carefully poured directly from its cooking pot, which generally has no pour spout, into the narrow neck of a containment bottle or the like for further handling.
Besides imparting a bad taste to foods being cooked, using the cooking oil too many times may result in the oil foaming like a bubble bath either when food is lowered into it, or spontaneously upon the oil being heated, with or without food. Such foaming vastly increases the amount of space required to contain the oil and food, and may result in the fryer being overflowed and hot oil potentially destructively dripping down to the countertop or other surface upon which the device is resting.
These small, countertop home use deep frying device also generally have no easy way of being cleaned. While the internal portion of the cook pots are typically cleaned by soap and water like any other cooking pan, because these devices also include electrical components for heating the device, it is important that such electrical components does not get wet or be exposed to water during the cleaning process. Thus, when cleaning such devices, it is important to avoid having water overflow into the electrical components particularly when the water is dumped out of the pans.
Large cooking pots required to fully immerse unitary pieces of food also means the devices may occupy substantial amount of valuable counter or floor space.
In recent years, large deep fryers, referred to as turkey fryers, have been successfully introduced into the United States market. Commonly these have very large cooking pots which are able to contain between 4 and 8 gallons of heated cooking oil while fully immersing and frying a medium to large sized turkey. These units have the capacity to hold from 2½ gallons to over 10 gallons of cooking oil, and the capacity to cook foods ranging from a few pounds, to well over a 20 pound turkey. Typically, such turkey fryers comprise a large metal bucket about a foot in diameter and a-foot-and-a-half high, which sits atop an open-frame support that contains a bottle gas fired burner. Some turkey fryers have metal lids similar to those found on saucepans, which are held in place only by gravity. These have gained a reputation of being unsafe.
Cooking turkeys or other large integral pieces of food, such as large cuts of meat, or large fish, vegetables, pastries, or fowl presents some significant problems.
Except for typically having no electronics to complicate cleanup, such conventional turkey fryers have most or all of the same problems described above, except on a larger scale due to their increased size. For example, instead of, in a small home countertop deep fat fryer, lowering a few ounces of French fries contained in a small basket into a few quarts of cooking oil, such turkey fryers may present their users with the task of with slowly lowering a 15 pound or larger turkey into over 5 gallons of hot, sputtering cooking oil. The cooking oil in such turkey fryers are contained in a tall, top-heavy, open bucket that rests precariously on an unstable platform which houses an open flame for heating the bucket contents. Thus, the act of accidentally dropping the food into the hot oil of such turkey fryer can have a result of a larger magnitude than splashes causes from dropping French fries into a few quarts of hot oil. Accidentally dropping a 15 pound turkey into the turkey fryer can cause the displacement of 5 gallons of hot oil, which could contact the user and/or which could come into contact the open flame burner and ignite, potentially resulting in further injury and/or property damage.
Safety issues may also arise from where and when turkey fryers are used. Generally, they must be used outdoors due to the open flame cooking element. The two most common times during the year that such turkey fryers are used in the United States are during Thanksgiving and Christmas. Cold and/or inclement weather are generally the rule in many parts of the United States during these times. A user may typically be in his or her driveway, under these weather conditions while trying to cook a large turkey. Additionally, there may be ice and/or snow on the ground. The task of slowly lowering a heavy turkey away from the user's body into a large, top-heavy, bucket containing hot oil precariously resting atop an unstable platform with an open flame may be dangerous under the best of circumstances, but being outdoors with cold and inclement weather, possibly combined with slippery footing, may make it especially hazardous.
Cleanliness may also be a problem with deep fat frying. During the deep fat frying cooking process, fats and oils may vaporize, and be disbursed into the air. Filtering air before it leaves a deep fat fryer may help to reduce contaminants in room air including cooking odors.
Viewing items being cooked may be a problem for both countertop home deep fat fryers as well as turkey fryers. Many home deep fat fryers have small horizontal windows in their lids to view the cooking progress. These windows, however, are virtually useless as steam condenses on their horizontal window surfaces and obfuscates the view. Also, construction of these small viewing windows includes many pieces, which are both expensive and time consuming to fabricate and assemble. In contrast, the food being cooked in a turkey fryers may be viewed by either looking into directly into the cooking bucket, in devices that are constructed without having a lid, or by removing any such lid that the turkey fryer may have. Both these situations present a hazard of directly exposing the user to the cooking oil with no intervening safety barrier.
Turkey fryers have at least one other typical hazard, that of overheating the oil due to lack of thermostatic control. Such fryers are typically heated by bottled gas-fired burners that generally have no thermostats or temperature control to shut the flame down when the oil has reached cooking temperature. By simply failing to turn down or off the flame at the appropriate time, cooking oils can be accidentally overheated to a point where they may produce smoke and possibly spontaneously combust into flame.
Recently, indoor use electric turkey fryers have made it into the marketplace. These units are primarily used on a kitchen countertop. The food to be cooked is hand lowered into the hot cooking oil at the end of a coat hanger like handle hooked onto a bucket-like bail handle, which is attached to a perforated pot which holds the food. Adding even a minimal 36 inch countertop height, and the 14 inch turkey fryer height, and the 8 inch high perforated bucket, and the 14 inches of handle above it, this may require the user to lift a 14 pound or larger turkey, away from their body, a distance of about 72 inches into the air just to load it. As noted above, the task of lowering the turkey into the hot cooking oil must slowly avoid splashing the hot oil. This is difficult for a six foot tall man, but may be nearly impossible for those of smaller stature.
In addition, the presence of an electrical cord introduces the opportunity for these new units to be accidentally pulled off the countertop by their cords, thus presenting new potential safety hazards associated with spilled hot cooking oil.
In addition, where wall powered electric heat is used to heat the oil, there may not be adequate power from residential wall plugs to heat large amounts of oil and food and keep them at desired frying temperatures.
Another issue in deep frying large foods is the cost of oil used in the cooking process. Cooking oils may be very expensive, particularly for higher quality oils. Large amounts of oil may also be difficult to store, and may be hard to dispose of once they are no longer of use.
In addition, large oil pots are needed in the frying process to fully immerse the large foods. This translates to expensive manufacturing costs, as well as costly shipping and large amounts of storage both before and after sale. It also means requirements for large amounts of valuable either countertop or floor space in order to use each of the full immersion devices.