Life is unpredictable, and freezer interruptions can happen without warning. Power outages, storms, or maintenance issues may cause frozen food to thaw and refreeze, creating serious health risks that are not always visible.

When food partially or fully thaws, bacteria can multiply rapidly—especially in meat, seafood, and dairy. Once power is restored, refrozen food may look normal while still being unsafe to eat.

This is especially concerning if you are away from home. A freezer malfunction during a trip can go unnoticed, leaving you unsure whether your food stayed frozen the entire time.

The coin-in-a-cup method offers a simple solution. Popularized online by Sheila Pulanco Russell, the trick provides a clear visual clue about whether your freezer lost power long enough to thaw.

To use it, fill a cup with water and freeze it solid. Once frozen, place a coin on top of the ice and return the cup to the freezer, leaving it there permanently.

If the freezer briefly loses power but stays cold enough, the coin will remain on top. If the ice melts and refreezes, the coin will sink before freezing again.

When you check the freezer, the coin’s position tells the story. A coin on top suggests food likely stayed frozen. A coin sunk partway or at the bottom indicates thawing, meaning perishable items may be unsafe.

This method removes guesswork and avoids relying on smell or appearance, which can be misleading. While not a replacement for food safety guidelines, it is an easy, effective precaution that can help protect your health and provide peace of mind.