How To Tell If An Egg Is Bad With The Float Test | Taste Of Home

There are a few ingredients I always have in my fridge, such as butter, eggs, cheese and bread. They last a long time and can become a satisfying meal in a flash, from quickly scrambled eggs and omelets to perfectly poached eggs on toast. Since eggs last in the fridge for three to five weeks, I have been guilty of grabbing a carton without looking at the date. All it took was one stinky, rotten egg to snap me out of that casual practice. Here, we’ve broken down how to tell if an egg is bad so you never have to take that risk.

Besides the fact that bad eggs are an olfactory nightmare, knowing the signs of a rotten egg can also save you from potential health risks. A spoiled egg can ruin a batch of cookie dough, but a bad egg can also make you sick with anything from an upset tummy to salmonella food poisoning, which can quickly become serious. This isn’t to scare anyone, but it’s a very real reminder that eggs are like any other perishable food—they don’t last forever.

From proper storage to quick freshness tests, we have all the information here to keep bad eggs out of your refrigerator and your food.

Quick Signs Your Eggs Are Still Good

Checking the date on your egg carton is the first step in assessing the age of your eggs. But treat it more like a guide than an absolute, since proper storage can shorten or extend an egg’s freshness. There are a few different numbers on your egg carton, including a code for when they were packaged and the correlating “best by” date, 30 days later. This is right in the middle of the three-to-five week window of how long eggs last.

Next, check your eggs for any cracks or damage to the shell, which can allow bacteria to get into the egg and begin to grow. If you accidentally lightly crack an egg while putting it away, it’s fine to cook it right then, but don’t put it back in the fridge for later. All other cracked or damaged eggs should be discarded.

Use the Float Test

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This low-tech method for how to tell if an egg is bad has been used for generations. Gently place an egg in a glass or bowl of water. If the egg sinks and lies horizontally, it’s very fresh. An egg that sinks but tilts upward is still usable but not quite as fresh. If it stands upright at the bottom of the container, it’s still safe but not for much longer. Make a batch of hard-boiled eggs to use them up. Finally, if it floats to the top, it’s gone bad and shouldn’t be used.

The reason the float test works is actually very simple. As eggs age, moisture from the egg evaporates through the semi-porous shell, allowing air to enter. Air is lighter than egg whites and yolks, causing the egg to rise in water, like a balloon. Although air itself isn’t bad, it can promote the decomposition of the egg and the production of harmful gases, which cause that terrible sulfurous smell we attribute to rotten eggs.

Tests After Cracking an Egg

If you didn’t check your eggs before cracking them, you can visually inspect them to judge if they are still good. Look for a yellow or orange yolk and a clear, or clear but cloudy, white. The color of an egg yolk has more to do with the chicken’s diet than flavor or freshness, but if there are flecks of green, pink, black, or any other color that isn’t yellow or orange, play it safe and toss the egg. If the white is liquidy or very runny, it’s a sign of an older egg, though not necessarily a bad one.

Your last line of defense (but probably the most obvious) should be the sniff test. If an egg passes all the other tests but smells like sulfur, just toss it. Don’t forget to crack your eggs individually into a bowl before adding them to the rest of the ingredients so that a rogue bad egg doesn’t ruin your recipe.

How to Keep Eggs Fresh

• Store them the right way: To keep your eggs from spoiling too quickly, there is a right way to store your eggs. Eggs purchased from the grocery store in the U.S. need to be stored in the refrigerator. Avoid using an egg holder built into the fridge door, as it’s prone to fluctuating temperatures. Store eggs on a bottom shelf or toward the back where it’s coldest. Farm-fresh eggs that have not yet been washed can be stored on the counter for a few weeks.
• Be aware of the temperature: Refrigerated eggs need to be kept cold to prevent bacteria, such as salmonella, from growing. The ambient temperature determines how long eggs can sit out and still be safe, with a maximum time of two hours or one hour if it’s 90 degrees or above. If you need room-temperature eggs for baking, cover them with warm water in a bowl for 10 to 15 minutes to quickly remove the chill.
• Use stale eggs sooner than later: If you are nearing your eggs’ expiration date or the float test is indicating older eggs, there are plenty of quick ways to use a lot of eggs, from elegant three-cheese souffles to meal prep-friendly egg breakfast casserole recipes. For something sweet, make light and airy meringues or a flourless chocolate cake, which relies on whipped eggs for structure instead of flour.
• Freeze them before they expire: If you are in a time crunch, you can also freeze eggs, raw or cooked, to use in the future. For raw eggs, separate and freeze the whites and yolks separately, or whisk a whole egg until combined before freezing. You can also cook, cool and freeze eggs (we think scrambled eggs hold up the best). Frozen eggs last up to a year in the freezer, but we found raw eggs are best used within four months and cooked eggs within six months.
• Avoid washing them: Refrigerated eggs have already been cleaned and sanitized. Rewashing them can introduce bacteria into the egg through the shell or cause hairline cracks. Farm-fresh eggs are a different story since they haven’t been USDA-graded before sale. These unwashed eggs can be pretty dirty, so it’s important to wash fresh eggs thoroughly right before using them.
• Check them for cracks: Most of the time, surface cracks or crushed eggshells are easy to spot. Hairline cracks can be harder to see, but they can still cause an egg to spoil. If you’re unsure, try the candling test, which is typically used to check eggs for growing chicks but works here too. Take your eggs into a dark room and shine a flashlight on them, looking for any cracks that the light can get through. Discard any cracked or damaged eggs to be on the safe side.
• Keep them away from odors: Since eggshells have tiny pores, not only can liquid seep through but so can strong odors from your refrigerator. To keep your fridge smelling fresh, store leftovers in airtight food storage containers, keep potent condiments well sealed and store eggs in their original carton to provide a barrier from odors. Finally, try one of our recommended best refrigerator odor eliminators to keep things as odor-free as possible.