Kettle chips occupy a special place in the snacking world. Their distinctive extra-crunchy texture, visible bubbles, and robust potato flavour set them apart from conventional chips. But what exactly makes a kettle chip different from its mass-produced cousins? The answer lies in a production process that, while modernised, remains fundamentally different from continuous production methods.
In this behind-the-scenes look, we'll follow the journey of a potato from farm to finished packet, exploring the unique steps that give kettle chips their characteristic qualities.
The Right Potato Makes All the Difference
Chipping Varieties
Not all potatoes are suitable for making chips. Kettle chip manufacturers use specific chipping varieties selected for their low sugar content and high starch levels. High sugar content causes chips to brown too quickly during cooking, while inadequate starch results in a softer, less crispy finished product.
In Australia, popular chipping varieties include Snowden, Atlantic, and Kennebec. These potatoes are specifically cultivated for chip production, often under contract with farmers who must meet strict quality specifications.
Quality Testing
When potatoes arrive at the processing facility, they undergo rigorous testing. Samples are checked for sugar content, specific gravity (a measure of starch content), and overall quality. Potatoes with sugar levels above acceptable thresholds are rejected, as they would produce dark, bitter-tasting chips.
Potato sugar content varies with storage conditions. Potatoes stored at cold temperatures convert starch to sugar, which is why chip manufacturers carefully control storage conditions and often "recondition" potatoes at warmer temperatures before processing.
Preparation: From Whole Potato to Slices
Washing and Peeling
The production process begins with thorough washing to remove soil and debris. Potatoes are then peeled using either steam peeling or abrasive peeling methods. Some premium kettle chip brands opt to leave skins on certain varieties for added texture and nutrition.
Slicing
Clean potatoes move to slicing machines that cut them to the desired thickness. Kettle chips are typically sliced thicker than conventional chips, usually around 1.5 to 2 millimetres compared to 1.2 millimetres or less for traditional chips. This extra thickness is crucial to achieving the robust texture that defines kettle chips.
Rinsing
After slicing, potato slices are rinsed in cold water to remove surface starch. This step is important for achieving consistent cooking results and preventing slices from sticking together during frying. The starch-laden rinse water is often recovered and processed for other uses.
The Kettle Cooking Process
Here's where kettle chips truly diverge from conventional production. The name "kettle chips" refers to the batch cooking method that defines this style.
Batch vs. Continuous Cooking
Conventional chips are cooked in continuous fryers, where slices enter at one end and exit as finished chips at the other. This efficient process cooks chips quickly at consistent temperatures.
Kettle chips, by contrast, are cooked in batches within large kettles or vats. Potato slices are lowered into hot oil all at once, causing the oil temperature to drop significantly. The chips then cook gradually as the oil temperature recovers.
Why Batch Cooking Matters
The variable temperature cooking creates several distinctive characteristics:
- Natural bubbles: The slower initial cooking allows steam to form bubbles that become trapped in the chip's structure
- Folded shapes: Chips curl and fold as they cook, creating their irregular, artisan appearance
- Extra crunch: The longer cooking time removes more moisture, resulting in a harder, crunchier chip
- Deeper flavour: Extended cooking develops more complex, roasted potato flavours
Stirring and Monitoring
During cooking, chips are stirred periodically to ensure even cooking. In traditional operations, this was done by hand using large paddles. Modern facilities often use automated stirring systems, though some premium brands still employ manual stirring for certain products.
Operators monitor the cooking process closely, watching for colour development and listening for the change in sound that indicates chips are approaching doneness. When the bubbling subsides and chips reach the desired golden colour, they're removed from the oil.
Seasoning and Flavouring
Oil Drainage
After cooking, chips are drained of excess oil. This typically occurs on vibrating conveyor belts or in spinning drums that use centrifugal force to remove surface oil. Proper oil drainage affects both the chip's texture and its fat content.
Seasoning Application
For flavoured varieties, seasoning is applied while chips are still slightly warm, which helps the flavouring adhere better. Seasoning tumbles or drums coat chips evenly with powdered flavourings.
Many kettle chip manufacturers pride themselves on using natural seasonings and avoiding artificial flavours. Simple varieties like sea salt may use nothing more than high-quality salt, while complex flavours combine herbs, spices, and natural flavour extracts.
Look at the seasoning distribution on kettle chips. Quality products should have relatively even coverage. Clumping or bare patches may indicate production issues or storage problems.
Quality Control
Inspection and Sorting
Before packaging, chips pass through inspection processes. Optical sorters use cameras and computers to identify and remove defective chips, including those that are too dark, too light, or damaged. Some facilities also employ human inspectors who sample products for taste and texture.
Moisture Testing
Final moisture content is tested to ensure chips meet specifications. Properly cooked kettle chips typically contain less than 2% moisture, significantly lower than the raw potato's 80% moisture content.
Packaging for Freshness
Nitrogen Flushing
Chip bags aren't filled with regular air. Instead, they're flushed with nitrogen, an inert gas that doesn't react with the chips. This nitrogen cushion serves two purposes: protecting chips from crushing during transport and preventing oxidation that would cause the oils to go rancid.
Barrier Packaging
Modern chip bags are engineered with multiple layers of materials designed to block light, moisture, and oxygen. This sophisticated packaging helps maintain freshness from the factory to your pantry.
The Craft Behind the Crunch
Understanding how kettle chips are made reveals why they command premium prices. The batch cooking process is inherently less efficient than continuous production. It requires more energy, more labour, and more careful monitoring. Each batch is subject to slight variations that give kettle chips their artisan character but require skilled operators to maintain consistency.
Modern kettle chip facilities blend traditional batch cooking principles with contemporary food technology. While the fundamental process remains true to its origins, improvements in automation, quality control, and food safety have made production more reliable and hygienic than ever before.
Next time you enjoy a kettle chip, take a moment to appreciate the journey it's taken. From carefully cultivated potatoes to the unique temperature dance of batch cooking, every step contributes to that satisfying crunch that makes kettle chips a cut above the ordinary.