How to Choose the Best Oil for Commercial Deep Frying

For most restaurants, takeaways and food plants, frying oil is one of the largest ingredient costs, and it affects every portion that comes out of the fryer. The cheapest oil per liter is rarely the cheapest per serving: an oil that lasts twice as long between changes can cost less overall, and give a cleaner taste. This guide explains what to look for and how the main frying oils compare.

What makes a good frying oil

• Oxidative stability. At frying temperatures, oil reacts with air and moisture from food and slowly breaks down. Oils high in monounsaturated oleic acid, and low in easily oxidized linolenic acid (omega-3), break down more slowly. This is why high-oleic sunflower, high-oleic canola and palm olein are popular for heavy frying.
• Smoke point. The temperature at which oil starts to smoke. Fresh refined oils typically smoke at around 220–245 °C (430–475 °F), well above normal frying temperatures. Smoke point falls as oil is used, so a high starting point gives more headroom.
• Neutral flavor. Refined oils have little taste of their own, so food tastes of itself and flavors do not carry between batches.
• Behavior at room temperature. Liquid oils are easy to pour and top up. Palm-based oils give a crisp, dry finish but may cloud or set in a cold kitchen.
• Cost per serving. Compare price per liter with how many hours or batches the oil lasts in your fryer.

How the main frying oils compare

Smoke points are typical values for fresh refined oil and vary with the oil and its condition. Each oil page lists its full specification.

Frying temperatures

Most frying is done between about 160 °C and 180 °C (320–355 °F). Frying hotter does not cook food much faster, but it speeds up oil breakdown. For potatoes, lower temperatures also limit acrylamide, a contaminant that forms when starchy foods are fried or baked. In the European Union, food businesses frying cut potato products such as fries must keep frying temperatures below 175 °C and follow the other measures in Regulation (EU) 2017/2158.

How to get more fry life

• Filter the oil daily, and skim crumbs and batter during service. Burnt particles speed up breakdown and darken the oil.
• Top up with fresh oil regularly. Steady replenishment keeps the oil in better condition for longer.
• Turn the fryer down in quiet periods, or switch it off, and cover it when not in use, to cut exposure to heat and air.
• Shake off ice and excess moisture before frying, and do not salt or season food over the fryer; salt and water both damage oil.
• Clean the fryer thoroughly when you change the oil, and rinse and dry it fully, as traces of detergent and water spoil fresh oil.
• Keep strong-flavored foods separate where you can, so fish or spiced items do not taint fries.

When to change the oil

Changing too early wastes money; changing too late hurts food quality and can be a regulatory issue. Signs that oil is spent include dark color, smoke at normal frying temperature, persistent foam, a sharp or fishy smell, and food that browns too fast or tastes stale.

The most reliable test is total polar compounds (TPC), measured with a handheld meter. The German Society for Fat Science (DGF) recommends discarding oil at 24% polar compounds, a figure widely used as a guide, and India’s food regulator FSSAI does not allow oil above 25% to be used. Measuring TPC at the same point each day lets you change oil based on its real condition.

Choosing the right pack for your fryer

Small kitchens usually buy 5L bottles or 20L jerrycans, which pour straight into a fryer. Busy restaurants and chains often use 20L jerrycans or 200L drums, while food plants with bulk oil systems take 1,000L IBC totes or 20,000L flexitanks. Our packaging guide compares every size.

Sources

• OFI Magazine: Deep frying regulatory update (DGF polar compounds recommendation)
• FSSAI: Guidance note on used cooking oil
• Commission Regulation (EU) 2017/2158 on acrylamide