How are French fries made commercially?

Commercial French fries are made through an 8-step industrial process using 163 million cwt of raw potatoes annually in the USA alone.

Preparation Phase:

The process begins with receiving and grading potatoes by size (minimum 50mm length for standard fries), specific gravity (minimum 1.080 for adequate dry matter), and defect tolerance (≤5% greening, ≤3% hollow heart) according to USDA Grade Standards. Potatoes are then washed and cleaned to remove stones and debris. Steam peeling at 15-20 bar pressure for 15-30 seconds removes 3-5% of potato weight, with water usage of 2-4 liters per kg of raw potato (FAO Post-Harvest Compendium).

Processing Steps:

High-pressure water cutters (30-40 bar) or mechanical blade systems cut potatoes into standardized strips — typically 7mm, 9mm, 11mm, or 13mm cross-sections, with the classic McDonald's size being 9×9mm (USDA ARS Processing Laboratory). Two-stage blanching follows: first at 70°C to activate pectin methylesterase for firming texture, then at 85°C for 10-20 minutes to gelatinize surface starch and reduce reducing sugars for color control.

Final Production:

Par-frying occurs in oil at 170-180°C, followed by rapid freezing at -30°C to -40°C before packaging. At restaurants or home, these frozen fries are finish-fried at 175-190°C. Russet Burbank potatoes dominate this process — their long, uniform shape, high specific gravity, and white flesh became the global standard after J.R. Simplot's 1965 deal with McDonald's established this variety as the benchmark for the entire industry.