According to the USDA, an unopened refrigerator will keep food safely cold for up to 4 hours, while a freezer will maintain food for 48 hours if full, or 24 hours if half full. During the outage we wrapped the refrigerator in a blanket (making sure not to cover the coils in back) to help keep it cool. We also avoided opening the fridge or freezer, going in just once to retrieve foods we could eat right away or that we didn't want sitting around indefinitely.
Once power was restored, we began the task of deciding what to keep and what to toss, using the USDA's Keeping Food Safe During an Emergency as a guide. In addition to tips and FAQs, it has "When to Save and When to Throw It Out" charts that list refrigerated and frozen foods in every category from meat to dairy, fruits, vegetables, condiments, and grains. Juice, we learned, was safe to keep but we'd have to discard the eggs (according to USDA guidelines, anyway; we recall seeing unrefrigerated eggs in Europe but that's a subject for another time!).
• Keeping Food Safe During an Emergency (USDA)
More tips from The Kitchn:
• Power Outages: How to Tell If Your Freezer Defrosted
• Are Any Condiments Safe to Keep After a Power Outage?