I am translating some suggestions on frying posted by Iginio Massari, the great Italian pastry chef, that he posted on his Instagram account. To his technical considerations, I add a little historical introduction.
Still in Renaissance age, we cannot speak of a process toward the creation of regional dishes, the cuisine still maintain an international print; the great differences are related to the social and economic status between the ones who can afford certain foods and luxuries, and the ones who are totally excluded because of economic and social reasons.
Even in the so-called “fasting days”, the tables of the rich were extremely luxurious and varied and, quite differently from current (or modern) Western logics, that see our meals organized in sequences going from savory dishes to sweet ones, our ancestors did not hesitate to mix savories, sour and sweet dishes.
An innovation of this period is the introduction of fried foods to the sequence of courses based on fish, vegetables and fruits that were considered less nourishing.
In many regional recipes we can see the dishes called “the great fried mix”, which join in an unique majestic course fried meats, vegetables, flowers and desserts, and vary according to the seasonality.
A necessary premise to an Italian article about frying is that the most common technique is shallow frying: most Italian fried dishes are in small pieces, whereas deep frying is used mainly in certain specific dishes like “arancini siciliani” and the famous “carciofi alla giudia”. However, these are somewhat exceptions.
The first common rule of frying is to bear the oil’s temperature in mind, as it must vary according to the type and size of the food we want to fry.
from 130° to 145° C (from 270° to 300° F): for vegetables, portioned fish, meats, and sweets. This not excessive temperature cooks foods thoroughly, while keeping them crisp and golden on the outside.
from 155° to 170° C (from 310° to 340° F): to fry foods which have already been partially cooked like potato croquettes, or foods coated with batter, dredged with flour, whisked egg or breaded. Upon contact with the oil, the coating will become hard and browned, preventing the inner part to seep out. Like fried custard or cutlets à la Milanese.
from 175° to 190° C (from 350° to 375° F): for very thin sweets that only require a few minutes of cooking, like cenci (link), for example.
Nevertheless, oil temperatures can experience some slight variations due to the frying method and the size of food pieces. Cenci, for example, can tolerate higher temperatures than tortelli (sweet ravioli); smaller pieces can be fried at 180° C (350° F), while larger pieces should be fried at 170°-175° C in order to ensure that the food is cooked thoroughly without overcooking the coating. In fact, the oil’s proper temperature creates a light crust that prevents the oils from seeping into the food while favouring even and complete cooking.
In general, the best advice is to have the foods ready to be cooked and the oil at the right temperature to prevent the foods from being exposed to air. In fact, contact with air creates a surface skin, which prevents the food from reaching the correct temperature and the subsequent partial or complete lack of leavening, typical of sweets prepared too soon. There must be enough oil in the frying pan to enable the foods to float without coming in contact with the bottom, which would cause imperfect cooking.