In common cases, the frying of French fries is carried out in two steps, par-frying and finish-frying, with a cooling step in between. Par-frying is usually handled in factory, and finish-frying is done in a fast-food restaurant or at home shortly before consumption.
The first fry takes about 5 to 6 minutes with a relatively low temperature at 325°F. The product will not take on much color at this stage. During par-frying, heat is transferred from the hot oil to the product, and part of water evaporates from the product surface in the form of steam bubbles, so that oil enters and occupies their place, contacting directly with the cells of the potato. With the help of energy provided by hot oil, larger starch granules break into individual molecules, which contact with the water that is still present in the potatoes, hydrating and forming a gel, reinforcing the surrounding cells structures. With the entering of the oil, a thick layer of such cells build up in the surface area, and thus a crust is formed.
After par-frying, the surface oil is removed by a de-oiling machine to minimize oil uptake, and then the product is cooled and frozen quickly, packaged and distributed. The freezing process extends the time between the two frying process, making storage and distribution possible. Packaged par-fried potato strips are easily stored in the frozen state without the need of the labor or equipment in the restaurant to peel or cut potatoes prehand. They can be fetched out from frozen storage quickly upon serving. With the frying machine, which occupies small kitchen floor space, a finish-frying is just ready to go. Not only time and labor are saved, but also the investment is lowered.
Finish-frying is the final fry just before serving, which crisping up the exterior to a beautiful golden brown. This fry is performed for about 1 to 2 minutes at a relatively high temperature of 375°F to expel the water residues, making the structure crisp and desiccated. Just with five-minute preparation, you will enjoy the delicious french fries. The finish-frying can either use the same type of oil as par frying, or a different type.
Semi-automatic frozen french fries production line is ideal for your business choice. It is special for small-scale production. The frying machine adopts advanced oil and water mixing technology, and the oil is in upper for frying French fries and water is at the bottom for absorbing the residues. This can prolong the service cycle of the oil and reduce the cost.