How French Fries are Made
How do McCAIN potato fries get from the farmer’s field to your business? This is a question that many have asked, so here it is – the process of making French fries.
After harvesting, the potatoes are brought to McCAIN in trucks equipped with conveyor belts for easy unloading. In the winter, the trucks are closed-in to protect the potatoes from freezing.
When entering the McCAIN plant, each truck crosses a scale which weighs the amount of potatoes. A record of this is kept and the grower is paid for the number of tonnes brought in. A sample is taken from every load to grade the potatoes for quality and colour.
Each load must meet stringent quality standards, otherwise McCAIN has the right to refuse the load altogether. This ensures that only the highest quality spuds make it from the farm to your foodservice business.
The potatoes then go into storage sheds until ready to be used, when they are flumed in a water rock remover to take out any stones that may have been mixed in during harvesting.
They then go through another rock remover, a washer, a length and size grader, and finally into high-pressure steam peelers. The next step is the brusher – a series of long round brushes which remove the loosened peel. This is collected and used in cattle feed.
Then comes trimming – which includes the removal of all black spots, bruises and unpeeled portions. Sun or wind-burned potatoes, or those with serious defects, are not allowed to go through the processing line.
The potatoes are next moved into large holding tanks filled with water before going to the strip cutter. There are two types – one for straight cut fries and one for crinkle cut. For the straight cuts, the potatoes are pumped through a “water gun” and cross hatch of knives to give the square shape.
After the potatoes are cut into strips, all the slivers (thin slices) and nubbins (short or broken pieces) which do not meet McCAIN’s specifications for length or size are separated out and used in one of several by-products (such as Hash Browns).
Once cut, the fries go to defect removal equipment to identify and remove any further defects, then to the blanchers. These are long cylindrical tanks holding water at 82°C.
The fries stay in the blancher for several minutes (depending on the time of the year). This destroys enzyme activity and removes excess sugars. The starch in potato slowly turns to sugar during storage, so the blancher helps maintain a constant sugar level at all times to ensure the fries have a consistent texture and colour.
After blanching and drying, the fries go into the fryer which has a temperature of 200°C. Each fry is par fried from ½ minute to 5 minutes depending on the type of potato.
The strips are then shaken on a vibrating conveyor to remove any excess cooking oil. Following this they are sent to the freezer, which has a temperature of -39°C, and kept for 20 minutes.
After this the fries are finally ready for packaging. The packaging machine weighs out fixed batches (1 kg, 1.5 kg, etc) and drops them into poly bags. The machine then folds, seals and cuts the bag from the roll.
The bags of fries are packed into cardboard boxes and stored in refrigerated rooms at -23°C.
The process of making French fries at McCAIN Foods is almost completely automatic. The only times they are touched by human hands are during the trim and inspection processes.
The efficiency of the French fry process line at McCAIN Foods allows thousands and thousands of tonnes of fries to be shipped out each day.