How to Store and Handle Bulk Cooking Oil

Good oil can be spoiled by poor storage long before it reaches the fryer or the production line. The good news is that the rules are simple. This guide covers what causes oil to deteriorate, how to store each pack size, and the temperatures recommended for bulk oils that set solid.

What makes oil go off

• Oxygen. Air slowly oxidizes oil, causing rancid, cardboard-like flavors. Keep containers closed and as full as practical.
• Heat. Every rise in temperature speeds up oxidation. Store oil in a cool place, away from ovens, fryers, boilers and direct sun.
• Light. Light, especially sunlight, accelerates oxidation, particularly in clear bottles. Store bottles in their cartons or in a dark storeroom.
• Metals. Copper and its alloys, such as brass and bronze, strongly catalyze oxidation, and iron does too to a lesser degree. The Codex code of practice for bulk oils says copper and its alloys should be rigorously excluded from tanks, pipes, valves and pumps.
• Water and contamination. Moisture, food debris and residues of cleaning agents shorten shelf life. Equipment should be clean and completely dry before it touches oil.
• Odors. Oil absorbs strong smells, so keep it away from chemicals, fuels and strongly scented goods.

Storing bottles, jerrycans and drums

• Store in a cool, dry, dark area, off the floor on pallets or shelving.
• Keep caps and bungs tightly closed between uses, and do not decant oil back into a container that has held used oil.
• Rotate stock first in, first out, and check the best-before date and lot code on each pack.
• Keep drums and IBC totes out of direct sun and away from heat sources, and use clean, dedicated pumps and taps.
• Clean up spills promptly: oil makes floors very slippery.

Storing oil in bulk tanks

• Tanks and lines must be clean and dry before filling, and drained and dried after any steam or water cleaning.
• Use stainless steel or suitably coated mild steel; exclude copper, brass and bronze fittings.
• Fill from the bottom, or through a pipe reaching the bottom, so oil does not cascade and mix with air.
• Tall, narrow tanks expose less oil surface to air. For long-term storage of high-quality oil, a nitrogen blanket helps prevent oxidation.
• Store liquid oils such as sunflower, soybean and canola at ambient temperature, with any heating switched off.

Temperatures for oils that set solid

Palm, palm kernel and coconut oils are semi-solid or solid in cool weather and need gentle warming for pumping. The Codex code of practice gives these temperature ranges:

Oil	Storage and bulk shipment	Loading and discharge
Palm oil	32–40 °C	50–55 °C
Palm olein	25–30 °C	32–35 °C
Palm kernel oil	27–32 °C	40–45 °C
Coconut oil	27–32 °C	40–45 °C
Soybean and groundnut (peanut) oil	Ambient	20–25 °C
Sunflower, olive, sesame and similar oils	Ambient	15–20 °C

Heat slowly: the code recommends raising the temperature by no more than 5 °C in 24 hours, preferring hot water at about 80 °C, and keeping steam below 1.5 bar gauge. Heating coils must be fully covered by oil before heating starts. Overheating, or heating oil in contact with air, damages its quality.

Receiving a flexitank

For a flexitank delivery, have your storage tank, pump and hoses ready before the container arrives. Flexitanks for palm, palm kernel and coconut oil are fitted with a heating pad, which is connected to a steam or hot-water supply to warm the oil before discharge. Plan enough time for gentle heating, and discharge promptly to avoid container charges.

Cloudiness and solidifying

Some oils turn cloudy or thicken when cold. Olive oil and unwinterized oils can cloud in a cold store, and coconut oil sets solid below about 24 °C. This is a physical change, not spoilage: the oil clears or melts again when it warms to room temperature. Winterized oils, such as our refined sunflower oil, are treated to stay clear when chilled.

Shelf life

Unopened shelf life depends on the oil and grade, and is stated on each oil page and on the pack. Refined oils generally keep longer than cold-pressed oils, which are best stored cool and used sooner. Once opened, keep containers closed and use the oil within a reasonable time.

Sources

• Codex Recommended International Code of Practice for the Storage and Transport of Edible Fats and Oils in Bulk (CAC/RCP 36-1987), FAO