Find the right capacity before buying
Identify the fryer or pan and read its instructions for the intended food and batch size. For a fryer, use the specified minimum and maximum oil levels. Do not estimate a safe fill from the vessel’s brim capacity: the food displaces oil and cooking needs headroom.
Record the instructed oil quantity for one fill, the bottle sizes sold and usable unopened stock. A purchase calculation can round that known quantity to bottles, but cannot decide the safe fill level for an unfamiliar appliance.
Separate one fill from multiple batches
Several batches in the same fill do not automatically require several complete fills of oil. Conversely, topping up is not a guarantee that used oil remains suitable. Follow the oil and appliance guidance for the food, temperature, filtering, storage and replacement.
As a purchasing example only, an appliance instruction requiring 2 litres and bottles containing 1 litre would require two bottles when no suitable stock is available. Changing the food load does not justify exceeding the appliance’s maximum mark. Compare bottle prices by litre with the Unit Price tool.
Keep the cooking plan supervised
Stay with frying food and keep combustible items away from the heat. The U.S. Fire Administration advises turning off the burner if oil smokes or starts to boil. Keep handles positioned so they cannot easily be knocked.
Never use water on an oil or grease fire. Do not move a burning pan; get to safety and contact emergency services if you cannot deal with the situation safely. Follow your local fire service’s guidance and the appliance instructions.