The most important part of deep frying is the type and amount of oil you use. This varies greatly when it comes to the amount of time needed to cook different dishes. The type of food you deep fry also matters, as certain foods may have less of a solid consistency (pickles, ice cream), which you don't want to overcook, in comparison to other foods like chicken or artichokes.
Oils have different "smoke points," which is the highest temperature for deep frying before food starts to smoke and develops a terrible, smoky flavour. If you're using a specific oil to deep fry a specific food, the temperature and time needed to cook in that deep fryer will vary, both due to the food itself and the brand of the oil (as smoke points can sometimes vary per brand). This is important to know when you're cooking at both high and low temperatures.
Foods to Fry
Different foods need to fry for varying amounts of time. Deep fried baby artichokes should fry at 176 degrees Cor about 2 minutes per batch because you want to just barely fry them. Pickles should fry at 176 degrees Cor about 3 to 5 minutes per batch, allowing them to be fried all the way through. Deep fried chicken can go as long as 10 to 12 minutes in the oil, while deep fried ice cream should only be dropped into the deep fryer for 5 to 8 seconds, as it will obviously melt. To give you a general idea of the speed at which certain foods brown, a cube of white bread dropped into a deep fryer at the standard 365 degrees browns in about 1 minute.
Types of oil
Oil also has different flavours to consider, which will affect frying times. Canola/vegetable oil is most widely used but sunflower and corn oils, which also have high "smoke points," should be considered. Each will deep fry the food in a slightly different way and time plays a factor in this, along with temperature.