In the deep-fryer
Here we find our French fries again. Whether refrigerated or deep‑frozen, they are prepared in the deep‑fryer, in exactly the same way as fried potatoes cut in rounds, parisiennes or in quarters, pommes noisettes or croquettes, and pommes dauphines.
As a general rule, these products are all precooked. Therefore, they have to be plunged only once into the frying fat.
If they are deep‑frozen, there is no need to thaw them out.
If they have just been defrosted, they can perfectly well be eaten. However, they must never be deepfrozen a second time. The structure of the potato does not endure recongealing, anymore man other food products do. Deep‑frozen products can be preserved for several months at temperatures minus 64°F and for 24 hours in the refrigerator. The chilled french fries can be preserved from 4 to 21 days in the refrigerator.
What type of frying fat should be used?
The Dutch products are always prefried in vegetable oil, an unsaturated fat which therefore is easier to digest. For final frying it's also preferable to use vegetable oil; the products will keep all of their flavour.
How high should the temperature be?
When the products are dipped into the deepfryer, the temperature of the frying oil should be at least 356°F, so that, directly after the thermal shock, the oil can quickly regain a high temperature. In this way firm, crisp and slightly oily products are obtained.
How should the product be portioned in relation to the amount of oil?
If the product is still frozen, it is preferable to plunge in small quantities at a time. The fries must be well‑covered by the oil. The temperature will rise faster. Because the products don't overlap, they will cook uniformly. It is advisable not to take the products out of the oil at the beginning of the cooking process.
Observations
Because evaporation of the water has taken place during industrial precooking, the potato products do not make the oil bubble. They do not lose any weight during final cooking. During first cooking, the products absorb a small amount of oil (about five to seven centilitres per kilogramme of the end product). That much will not be absorbed again during final cooking.