Because of its high smoke point, grape seed oil has become a favorite of home chefs for frying and other high temperature cooking applications. Of course, you’re unlikely to use a whole bottle for a recipe! How long will that open bottle last, and does grape seed oil go bad?
Does grape seed oil go bad?
Like all oils, grape seed oil does go bad. While oils do not mold, or rot in the traditional sense, they do go rancid. Rancidity occurs when the oil is oxidized, which can happen with exposure to light, heat or oxygen for extended periods of time. Rancid oils have not only lost all of their health benefits, but they actually become damaging to the body, and thus should not be consumed.
Signs of Spoilage
Like all oils, grape seed oil will develop an unpleasant odor and taste when it has gone rancid. Be sure to smell oil before using to check for rancidity. You may also notice changes in the color of the oil, though this does not always accompany rancidity. Once oil has gone rancid, it should not be consumed.
Image used under Creative Commons from Paul Haahr
If you store your oil very cold temperatures, you may notice that it becomes cloudy, or even solid. This is not a sign that the oil has gone bad, but is simply a reaction to the cold. Solidified oils will become liquid again after a few hours at room temperature, and are completely safe to consume. If an oil has frozen completely solid, you may want to use it quickly, as it is likely to spoil sooner. To be safe, you should always smell an oil before using it, to make sure that it is not rancid.
Storing Grapeseed Oil
When stored in a cool, dark place like your pantry or cellar, grape seed oil can have a shelf life of up to three months past the written expiration date. Grape seed oil should be kept in a tightly sealed dark glass container, and should not exposed to temperatures above 70 degrees Fahrenheit. Because of its sensitivity to light and heat, bottles of grape seed oil should not be stored on your countertop, above your refrigerator, or next to the stove.
Refrigerating grape seed oil can extend its shelf life to six months past the written expiration date. Even in the refrigerator, grapeseed oil is best kept in a dark glass, tightly sealed container. If you purchased oil in a clear container, you may want to transfer the oil to a dark bottle or jar to prolong its shelf life.
Freezing Grape Seed Oil
Freezing grape seed oil is not recommended as a way to prolong its shelf life. The oil will actually freeze really well, and can keep for up to a year in the freezer, but the shelf life of thawed grape seed oil is significantly reduced. Because the compounds in the oil will be changed from the freezing process, the thawed oil should be consumed within a week. So, while you can certainly freeze a dish containing grapeseed oil, freezing a whole bottle doesn’t really make sense.
Though freezing the whole bottle is not recommended, you can use grape seed oil to preserve fresh herbs in the freezer. Chop fresh herbs and distribute into an ice cube tray with a lid that allows for sealing. Pour oil on top of the herbs, so that they are completely covered. Seal and store for up to a year. This will allow you to have portioned out herbed oil to use for cooking dishes. Cubes of oil do not need to be thawed, and can be used immediately.