Avoid rancidity by following these steps:
Keep oil in the dark: A closed, dark cupboard is a perfect place to keep the oil.
Keep oil cool:To maintain quality of your favorite oil, store it at a cool temperature and away from the stove or heat producing appliances.
Tight-lid:Air is also an enemy to oil. It is important to ensure that the lid is always tight.
Check the date:Old oil will change in texture and flavour, especially with olive oil.