Leaving a frosted cake out overnight is generally not recommended. However, there are some factors to consider when determining if a frosted cake can safely sit at room temperature overnight without refrigeration.
Quick Answers
Here are quick answers to common questions about leaving frosted cakes out overnight:
- It’s best to refrigerate cakes with dairy-based frostings like buttercream or whipped cream frosting overnight.
- Frosted cakes with non-dairy frostings like fudge or fondant can be left out at room temperature overnight if the room is below 70°F.
- Whole frosted cakes with fillings should always be refrigerated overnight as the interior can still harbor bacteria.
- Refrigerating overnight is highly recommended for frosted cake slices, cupcakes, and cakes with fresh fruit.
- A frosted cake can be left out up to 2 hours before the quality starts to decline. After that, refrigeration is advised.
Factors That Determine Safety
There are several key factors that determine whether a frosted cake can safely sit at room temperature overnight:
Type of Frosting
The ingredients in the frosting greatly impact safety. Frostings containing dairy products like butter, cream cheese, or whipped cream are perishable and must be refrigerated to prevent bacterial growth. On the other hand, frostings using chocolate, fudge, fondant, or royal icing have a lower water content and do not require refrigeration. Fruit-based frostings should also be refrigerated.
Storage Temperature
The temperature of the room plays a role. While refrigeration is best, cakes can sit out at room temperatures below 70°F for a brief period before quality declines. Temperatures above 70°F allow faster bacteria growth.
Single Servings vs Whole Cakes
Individually portioned items like slices and cupcakes have more exposed surface area and should always be refrigerated overnight. Whole cakes have less exposed area, but refrigeration is still recommended.
Fillings
Cakes with perishable fillings like pastry cream, fresh fruit, cheese, custard, or chocolates should be refrigerated regardless of frosting type. The interior can still breed bacteria.
Time Sitting Out
The 2 hour rule applies to cakes as well. Baked goods with frosting should be refrigerated after sitting out for more than 2 hours at room temperature. The longer a cake sits out, the greater the risk of spoilage.
Dairy-Based Frostings
Common dairy-based frostings include:
- Buttercream
- Whipped cream
- Cream cheese
- Ganache
- Meringue
- Custard
- Pastry cream
Dairy ingredients are highly prone to bacteria growth when left out too long. Cakes with these frostings should always be refrigerated if not being served immediately. Leaving them out overnight allows dangerous bacteria like E. coli and Salmonella to rapidly multiply to unsafe levels.
Steps to Refrigerate Cakes with Dairy Frostings
Here are tips for properly refrigerating cakes with dairy-based frostings overnight:
- Allow freshly frosted cakes to sit at room temperature no longer than 2 hours before chilling.
- Lightly cover cakes with plastic wrap or a cake dome before refrigerating.
- Refrigerate whole cakes for up to 5 days.
- Refrigerate cake slices and cupcakes for up to 3 days.
- Always store cakes on the top shelf of the refrigerator, the coldest area.
The refrigerator temperatures below 40°F slow down the growth of bacteria. Storing cakes properly prevents the frosting from crusting over or becoming soggy.
Thawing Refrigerated Cakes
To thaw a refrigerated frosted cake with dairy frosting:
- Remove the cake from the refrigerator and unwrap.
- Allow the cake to stand at room temperature for 1-2 hours until the frosting softens.
- Very gently smooth any condensation on the frosting using a spatula or knife.
- Avoid refrigerating and re-refrigerating the cake as this alters the texture.
The cake may need slight touch-ups but thawing brings the frosting back to a spreadable consistency.
Non-Dairy Frostings
Popular non-dairy frostings include:
- Chocolate fudge
- Ganache
- Royal icing
- Rolled fondant
- Marshmallow fondant
- Vegan buttercream
Non-dairy frostings have a lower moisture content which limits bacteria growth at room temperature. However, they can still support microbial growth so refrigeration is recommended.
Guidelines for Leaving Cakes Out with Non-Dairy Frosting
Here are some guidelines for leaving cakes with non-dairy frostings out overnight:
- Only leave out cakes frosted with chocolate, ganache, fondant, or royal icing.
- Refrigerate any cakes with fruit puree or juice added to frosting.
- Room temperature should remain below 70°F overnight.
- Refrigerate if room will be above 70°F for extended periods.
- Consume cake within 2 days of leaving out overnight.
- Do not leave out frosted cake slices or cupcakes.
While these frostings inhibit bacterial growth better than dairy-based ones, they can still deteriorate in quality if left out too long. Storing in the refrigerator is the best way to preserve decorated cakes.
Signs of Spoilage
Look for these signs that a non-dairy frosted cake has spoiled after sitting out too long:
- Frosting weeping or melting
- Watery or gelatinous texture
- Mold growth
- Unpleasant sour odor
- Dry, cracked frosting
Discard the cake if any of these changes are noticed after leaving it out overnight. Do not take risks consuming deteriorated frosting.
Steps for Refrigerating Cakes
Here is a summary of the best practices for refrigerating frosted cakes overnight:
- Choose cakes with non-dairy frostings if you need to leave them out. Avoid dairy-based frostings.
- Check room temperature is below 70°F before leaving cakes out overnight.
- Refrigerate sliced cakes, cupcakes, and cakes with fillings regardless of frosting type.
- Lightly cover cakes with plastic wrap or a cake dome before chilling.
- Refrigerate on the top shelf of the refrigerator, the coldest spot.
- Allow 1-2 hours thawing time for refrigerated cakes to regain texture.
- Discard any cakes kept out that show signs of spoilage.
Following refrigeration guidelines ensures that frosted cakes stay safe to eat and maintain quality.
Storing Cake Leftovers Safely
Refrigerating leftover frosted cake is important for minimizing foodborne illnesses. Follow these recommendations:
- Cover cake tightly in plastic wrap or airtight container.
- Refrigerate within 2 hours of cutting into the cake.
- Consume leftovers within 3-5 days.
- Do not store at room temperature longer than 2 hours.
- Discard cake if it develops a strange odor or appearance.
These proper storage techniques prevent harmful bacteria growth on leftover cake slices. Promptly storing and consuming leftovers gives everyone peace of mind.
Freezing Frosted Cakes
Freezing is a great long-term storage method for frosted cakes. Here are some tips:
- Double wrap cakes in plastic wrap and foil before freezing.
- Freeze unfrosted cakes for longer shelf life.
- Add cake boards beneath bottom layer for support.
- Freeze whole cakes up to 2-3 months.
- Freeze cake slices or cupcakes up to 1 month.
- Thaw overnight in the refrigerator.
Freezing prevents frosting from absorbing odors and locks in freshness once decorated cakes are firm. It allows enjoying cakes for special occasions weeks later.
Troubleshooting Frosting Condensation
Refrigerating cakes can sometimes lead to frosting condensation once thawed. Try these fixes:
- Use a cake board so surface doesn’t directly touch refrigerator shelf.
- Avoid large temperature swings by setting refrigerator below 40°F.
- Let cakes come closer to room temperature before serving.
- Add corn syrup or glycerin to frosting to minimize weeping.
- Lightly blot moisture off frosting using paper towel.
With proper thawing time and techniques, frosted cakes retain their decorations and taste delicious.
Conclusion
Leaving frosted cakes out on the counter overnight is generally risky business. To ensure food safety and quality, it’s best to refrigerate cakes with dairy-based frostings. Cakes with non-dairy frostings have a better chance of lasting out of the fridge overnight in cool temperatures if properly stored. But refrigeration is still the gold standard. Following guidelines on storage temperatures, frosting types, cake portions, and thawing allows enjoying your frosted cake creations without the worry.