How Are French Fries Made in a Factory? Equipments List, Processes, Quality Control & Global Shipping

French fries are a global favorite. How are French Fries Made on an Industrial Scale? In this article, we take you behind the scenes of how frozen French fries—especially those made from premium McCain potatoes—are manufactured in a factory, stored, frozen, and shipped around the world. We’ll also explore variations such as VF (Vacuum Frying) fries and how each process contributes to quality and flavor.

1. Raw Material: The Potatoes Behind Perfect French Fries

a. Potato Variety – McCain Potatoes

Most factory-made French fries use specific cultivars optimized for frying, such as Russet Burbank or proprietary varieties developed by McCain Foods. These potatoes are known for:

• High dry matter content (20–24%), which reduces oil absorption

• Long, uniform shape for consistent cutting

• Pale color that minimizes browning when fried

“The suitability of a potato cultivar for French fry production is largely determined by its starch content and reducing sugars” (Smith, 2017).

b. Cultivation and Procurement

Leading manufacturers like McCain grow their potatoes through contract farming, ensuring:

• Consistent quality from seed to harvest

• Control over pesticide and fertilizer use

• Optimization for machine processing

Some factories also purchase from third-party certified growers, but with strict quality control standards.

c. Storage and Preprocessing

After harvest, potatoes are stored in temperature-controlled facilities:

• Temperature: 7–10°C to prevent sprouting

• Ventilation: Maintains air quality and reduces rot

• Sorting: Removes green or damaged tubers

2. Detailed Production Process of Frozen French Fries

The manufacturing of French fries involves a multi-step, high-speed process designed to preserve texture, taste, and safety. Let’s break it down:

a. Receiving and Washing

• Potatoes are washed thoroughly in rotating drum washers to remove dirt and stones.

• Sorting machines remove undersized or damaged tubers.

b. Peeling

• Steam peelers or abrasive rollers remove the skin.

• Excessive peeling is avoided to reduce waste.

c. Cutting

• High-speed water or mechanical knives cut potatoes into sticks (e.g., 7mm, 10mm, crinkle cut).

• Water flumes transport cut fries quickly to prevent browning.

d. Blanching

• Fries are blanched in hot water (70–90°C) for 2–3 minutes.

• Purpose:

  • Deactivate enzymes

  • Reduce sugar content (preventing excessive browning)

  • Pre-cook to reduce final frying time

“Blanching improves fry texture and color by leaching out reducing sugars and activating pectin methylesterase” (Gould, 2018).

e. Drying

• Surface moisture is reduced in hot air dryers.

• Proper drying ensures better oil uptake control and prevents sogginess.

f. Pre-frying

• Fries are quickly fried for 30–60 seconds in vegetable oil (usually sunflower or canola).

• Temperature: 175–185°C.

• This step forms the outer crust while keeping the inside moist.

g. Freezing

• Fries pass through a cryogenic tunnel or spiral freezer.

• Temperature: -18°C or lower.

• Individually Quick Frozen (IQF) process prevents clumping and ensures convenience.

h. Packaging

• Frozen fries are packed in moisture- and oxygen-resistant bags.

• Nitrogen flushing is sometimes used to prevent oxidation.

• No preservatives are added; freezing preserves freshness naturally.

“IQF is the industry standard for preserving texture and preventing freezer burn” (IFPA, 2020).

3. Cold Chain Logistics & International Transport

To maintain quality from factory to fork, an unbroken cold chain is essential:

a. Factory Cold Storage

• Packed fries are stored in -20°C warehouses with real-time temperature monitoring.

b. Container Loading

• Export containers are pre-cooled and equipped with temperature recorders.

• Pallets are arranged for proper air circulation.

c. Global Shipping

• Transportation by reefer containers via sea or truck.

• Common destinations: USA, EU, Middle East, Asia.

• Transit time is optimized to ensure fries remain frozen throughout the journey.

4. Alternative Frying Technology: VF (Vacuum Fried) French Fries

Vacuum frying is a healthier alternative, especially for snack-type fries:

a. VF Process Overview

• Fries are fried under reduced pressure (typically 60–70 kPa) at lower temperatures (~120°C).

• Lower temperature reduces:

  • Acrylamide formation

  • Nutrient loss

• Often used for producing non-traditional fries (e.g., sweet potato, purple potato)

“Vacuum frying preserves the natural color and flavor better than atmospheric frying” (Shyu & Hwang, 2001).

b. Use Case

• Premium snacks

• Health-conscious markets

• Often paired with baked or air-dried alternatives

5. Ensuring Quality & Preventing Degradation

Quality assurance is embedded in every stage:

Common Factors That Affect Quality:

• High sugar potatoes → Browning

• Improper drying → Oil-soaked fries

• Oil re-use → Off flavors or trans fats

• Freezer delays → Product clumping

How are French Fries Made (with Equipment List)

The manufacturing of frozen French fries follows a highly automated, hygienic, and standardized process. Below is the updated step-by-step guide, including the main equipment used at each stage.

a. Receiving and Washing

Purpose: Remove soil, stones, and foreign objects from freshly harvested potatoes.

Main Equipment:

• Infeed conveyor

• Dry dirt remover

• Drum washer or brush washer

• Destoner

• Optical sorter or roller sorter (for defective tubers)

b. Peeling

Purpose: Remove the outer skin for a smooth surface and flavor consistency.

Main Equipment:

• Steam peeler (high-pressure steam loosens the skin)

• Abrasive peeler (rotating rollers strip the skin)

• Peel waste conveyor

Steam peeling is faster and reduces yield loss compared to mechanical peeling (Gould, 2018).

c. Cutting

Purpose: Uniform cutting into French fry shapes (e.g., 7×7 mm, 10×10 mm).

Main Equipment:

• Centrifugal cutter or water-knife system

• Cutting grid assemblies

• Water flume conveyor (for rapid transport and anti-browning)

d. Blanching

Purpose: Inactivate enzymes, reduce sugars, improve texture and color.

Main Equipment:

• Continuous blancher with hot water or steam

• Temperature and time control systems

• Heat exchanger (for water reuse and energy saving)

e. Drying

Purpose: Remove surface moisture before frying to reduce oil absorption.

Main Equipment:

• Multi-zone air dryer or belt dryer

• Air flow and humidity control unit

• Infrared moisture sensors

f. Pre-frying

Purpose: Partially cook the fries and develop a crust.

Main Equipment:

• Continuous fryer (stainless steel belt conveyor type)

• Oil circulation and filtration system

• Oil level and temperature control system

• Oil degassing & replenishment unit

High-efficiency fryers ensure consistent crust formation while controlling acrylamide levels (IFPA, 2020).

g. Freezing (IQF)

Purpose: Individually quick-freeze fries to -18°C or lower.

Main Equipment:

• IQF freezer tunnel (cryogenic or mechanical)

• Spiral freezer or fluidized bed freezer

• Conveyor with anti-clump agitators

• Core temperature monitoring system

h. Packaging

Purpose: Pack the product in a way that prevents moisture ingress and oxidation.

Main Equipment:

• Weighing and portioning machines

• Form-Fill-Seal (FFS) machine

• Gas flushing (optional nitrogen injection)

• Metal detector and X-ray inspection unit

• Labeling and coding system

Additional Equipment Used Across the Plant:

4. Alternative Frying Technology: VF (Vacuum Fryer) – Equipment

a. VF Equipment Line

• Vacuum fryer chamber with oil heating system

• Vacuum pump unit (maintains low pressure during frying)

• De-oiling centrifuge

• Condensation and deodorization system

• Oil filtration and reuse unit

VF equipment typically operates at 90–120°C under ~60 kPa, ensuring less oxidation and crispier, low-oil-content fries.

References (APA Style)

• Gould, G. W. (2018). Industrial Processing of Potato Products. Springer.

• IFPA. (2020). Cold Chain Best Practices for Frozen Foods. International Food Packaging Association.

• Shyu, S. L., & Hwang, L. S. (2001). Effects of processing conditions on the quality of vacuum-fried apple chips. Food Research International, 34(2–3), 133–142.

• Smith, D. (2017). Potato Biology and Biotechnology: Advances and Perspectives. Elsevier.

Conclusion

From carefully selected McCain potatoes to advanced freezing and global shipping logistics, French fry manufacturing is a blend of agriculture, engineering, and food science. By optimizing every step—from peeling to packaging—manufacturers ensure that consumers around the world can enjoy crispy, golden fries with every bite.