Deep-Fat Fryers Explained
Despite the name, food in a deep-fat fryer typically cooks in the top two inches of oil rather than being fully submerged. That makes it important to choose a fryer that matches your actual kitchen needs, rather than one that heats far more oil than you'll ever use.
A common mistake is buying a fryer based on peak demand days, such as a Friday fish and chips rush, rather than average daily throughput, or misreading chips-per-hour ratings without accounting for different chip types (frozen, chilled, blanched, or different sizes). Ask manufacturers to calculate capacity based on weekly throughput so the fryer genuinely suits your operation.
Gas vs electric fryers
Both have their advantages, and the right choice depends on your kitchen's volume and energy costs. Electric fryers have a lower upfront cost, suit low to medium volumes, and have become increasingly efficient as the technology has advanced. Gas fryers suit high-volume operations, particularly chips, are potentially cheaper to run over time, but carry slightly higher servicing costs due to gas system checks.
Gas heating systems vary: tube burners use gas jets inside wide tubes to transfer heat to the oil, a bank of gas jets concentrates heat outside the fry tank, and infra-red heaters give high-output heat for rapid cooking.
Fryer capacity and cooling zones
Cool zones prevent oil burn by collecting food debris below the level of the heat source, keeping it up to 30°C cooler than the cooking oil, which reduces oil breakdown and extends its lifespan. Busy kitchens should have at least two fryers, one for chips and one for other fried foods. Some modern electric fryers, especially smaller models, may not need a cool zone at all.
Oil filtration systems
Proper oil management matters for both food quality and fryer longevity. The traditional method, a bucket, sieve and tea-towel, is less safe and inefficient. A freestanding or built-in oil filtration system filters oil while it's hot and returns it to the tank in three to five minutes, with simple button operation that reduces safety risks and saves time. Daily filtration is essential for consistent food quality.
Good frying practice
Avoid overloading the fryer, as it reduces cooking efficiency. Remove food debris from the oil regularly, and keep a dedicated fryer for different food types to prevent flavour transfer between them.
Maintenance and care
Although fryers have few moving parts, proper care is still essential. Monitor oil temperature to prevent degradation, and filter oil daily to extend its life. Clean fry baskets regularly in a dishwasher to prevent oil build-up, and avoid letting baked-on oil taint new oil. Degrease the fry tank periodically with non-abrasive detergents, using plastic or soft scrubbers to avoid damaging the heating elements, and rinse thoroughly after cleaning. Clean around control dials to prevent grease build-up, and inspect and maintain auto-lift mechanisms as part of the service cycle, again avoiding harsh abrasives. During routine servicing, engineers will clean and inspect fryers, but pre-cleaning by kitchen staff reduces cost and service time; keep stainless steel casings and surrounding areas free from congealed oil.
Best practice summary
Do: remove food debris as directed, keep fry baskets and tanks clean, use oil filtration systems daily, and monitor grease build-up behind the fryer.
Don't: use abrasive cleaners on fry tanks, overload fryers, let grease accumulate on control dials, or damage heating elements during cleaning.
Browse our range of commercial deep-fat fryers, or call 01304 873469 to talk through the right fryer for your kitchen.
Reproduced with kind permission of the Catering Equipment Suppliers Association (CESA).