Can Margarine Go Bad

Margarine provides a dairy-free way to enjoy buttered toast, and flaky pie crusts. But often, those large tubs tend to be too much margarine to eat within a few weeks. Can margarine go bad? How long will margarine last?

Can margarine go bad?

Surprisingly, margarine can actually go bad, and the shelf life may be shorter than you think. Unopened, margarine will remain good for three to four months past the printed expiration date. Opened margarine will only stay fresh in your refrigerator for a month before going rancid, so while it may be tempting to buy those massive discount tubs of margarine, unless you plan to consume the entire tub within a month, they’re not worth the investment.

Storing Margarine

Margarine should always be kept sealed in your refrigerator. Exposure to air, light and heat can all oxidize the fats in margarine, causing rancidity and spoilage. Because of its sensitivity to temperature, it’s best to keep margarine in the interior of your refrigerator, where the temperatures are cooler and more stable, as opposed to on the door.
I Can't Believe It's Not Butter Light label

Image used under Creative Commons from ilovebutter

Freezing margarine is an excellent way to extend its shelf life. Margarine can stay good in the freezer for up to a year. Be sure that the packages are tightly sealed, as fats are very likely to take on the flavors of other foods that may be in the freezer. You may even want to seal sticks of margarine in freezer bags, for an extra layer of protection.

Sticks of margarine will freeze with no noticeable texture change upon thawing, though tubs of margarine may separate a bit after thawing, depending on the brand. This shouldn’t have too much of an impact on texture or flavor, and the margarine can be mixed back together, and used as intended. To thaw margarine, leave in the refrigerator overnight. Margarine should not be thawed at room temperature.

Signs of Spoilage

Sight and smell are the two best indicators that margarine has spoiled. Fresh margarine will appear smooth and soft, and will have a pleasant, butter smell. Margarine that has spoiled may have a darker, hard or waxy appearance. Spoiled margarine will not smell buttery, but may smell like soap or paint, or like old microwaveable popcorn.

Another sign of spoilage with margarine are droplets of liquid that have reached the surface of the spread. Fresh margarine should be completely mixed, and won’t separate. Once margarine starts to separate, and drops of liquid form, the margarine should not be consumed. An exception to this is margarine that has been frozen. Frozen margarine may separate upon thawing, as a result of the moisture content of margarine, and this is not a sign of spoilage.

If a tub of margarine is left on the counter overnight, it will likely start to separate and go rancid. Tubs of margarine are less stable that sticks, and more sensitive to temperature, as they are designed to be more spreadable. If you leave a tub of margarine at room temperature overnight, be sure to check for separation, discoloration, an off smell or any other signs of spoilage.

Because of the high content of saturated fat, it is unlikely that margarine will grow mold. Any mold would likely be from outside contaminants, like bits of food left on a knife used to spread the margarine. Mold growth certainly indicates spoilage, and the margarine should be discarded.