How Long Buttercream Icing Stays Fresh in the Refrigerator

Buttercream lasts 1 to 2 weeks in the refrigerator, depending on the type

American buttercream — made with butter, powdered sugar, and milk or cream — keeps for about 2 weeks when stored in an airtight container on a refrigerator shelf. Swiss or Italian meringue buttercream, which uses egg whites cooked with sugar syrup, also lasts roughly 2 weeks because the heat treatment kills bacteria. Cream cheese frosting is the shortest-lived at 1 to 2 weeks, since cream cheese spoils faster than butter alone. The exact timeline depends on how fresh your ingredients were when you made the frosting and how consistently cold your refrigerator stays.

Temperature matters more than you might think. Buttercream begins to separate and develop off-flavors when the temperature fluctuates — opening the door repeatedly or storing it near the back where it freezes slightly will shorten its life. Keep it in the coldest, most stable part of your fridge, usually the middle or lower shelf away from the door.

Key Takeaways

• American buttercream keeps for 2 weeks in an airtight container on a stable refrigerator shelf.
• Cream cheese frosting lasts only 1 to 2 weeks because cream cheese spoils faster than butter.
• Store buttercream away from the refrigerator door to avoid temperature swings that cause separation.
• Frosted cakes last 3 to 5 days in the refrigerator, but plain buttercream in a container lasts longer.
• Buttercream can be frozen for up to 3 months if you need to keep it beyond 2 weeks.

Why buttercream separates and how to tell it has gone bad

Buttercream is an emulsion — tiny droplets of water suspended in fat. When temperature swings occur, the emulsion breaks. You will see a greasy layer on top or a watery layer on the bottom. This does not always mean the frosting is unsafe to eat, but it signals that the texture and taste have changed. Separated buttercream can sometimes be saved by letting it come to room temperature and re-beating it, but if it has been in the fridge for more than 2 weeks, discard it.

Signs that buttercream has truly spoiled include a sour or off smell, visible mold, or a slimy texture. American buttercream made with real butter is less prone to mold than cream cheese frosting because butter has lower water content. If you see any fuzzy growth or smell anything fermented, throw it away — the risk is not worth it.

Storing buttercream in the refrigerator the right way

Use a glass or plastic container with a tight-sealing lid. Plastic wrap or foil alone will not protect buttercream from absorbing odors from other foods in your fridge — and buttercream absorbs them quickly. If you are storing a frosted cake, place it on a plate, cover it loosely with plastic wrap first (so the wrap does not stick to the frosting), then place the whole thing in a cake box or large container with a lid.

Do not store buttercream next to strong-smelling foods like onions, garlic, or fish. Buttercream is porous and will pick up those flavors within days. If your refrigerator tends to smell, keep the lid on tight and consider placing an open box of baking soda on the same shelf to absorb odors before they reach the frosting.

The difference between storing frosted cakes and plain buttercream

A frosted cake in the refrigerator lasts 3 to 5 days because the cake itself dries out and the frosting can separate from moisture in the air. Plain buttercream in a sealed container, with no cake to absorb moisture, lasts the full 2 weeks. If you frost a cake and know you will not serve it for more than 3 days, consider frosting it closer to serving time and storing the buttercream separately.

Unfrosted cakes can be wrapped and refrigerated for up to a week, then frosted when you are ready to serve. This approach gives you fresher-tasting cake and frosting. If you are making buttercream ahead for a specific event, store it plain in a container and frost the cake the day before or the morning of serving.

Freezing buttercream for longer storage

If you need buttercream to last longer than 2 weeks, freeze it. American buttercream and Swiss meringue buttercream freeze well for up to 3 months in an airtight container or freezer bag. Cream cheese frosting can be frozen but may separate slightly when thawed, so re-beat it after thawing to restore the texture.

Thaw buttercream in the refrigerator overnight, then let it sit at room temperature for 30 minutes before using. Do not thaw it at room temperature from the start, because condensation will form on the surface and water down the frosting. If the thawed buttercream looks grainy or separated, beat it for 2 to 3 minutes with an electric mixer until it smooths out.

Room temperature storage and when it is safe

Buttercream made with butter can sit at room temperature (68 to 72 degrees Fahrenheit) for up to 8 hours, depending on your kitchen temperature. On a hot day or in a warm kitchen, reduce that to 4 to 6 hours. Cream cheese frosting should not sit out longer than 2 hours because cream cheese softens and spoils faster than butter.

If you are frosting a cake for a party and the room will be warm, keep the frosted cake in the coolest part of your home — away from direct sunlight and heat sources — and cover it loosely. Once the party ends and leftovers go back in the fridge, the frosting will firm up again. Buttercream is forgiving as long as you do not leave it in heat for extended periods.

Identifying the type of buttercream you have made

American buttercream is the most common home recipe: butter, powdered sugar, vanilla, and a splash of milk. It is soft at room temperature and firms up in the fridge. Swiss meringue buttercream uses egg whites whisked over a double boiler with sugar, then butter is beaten in — it is silkier and more stable than American. Italian meringue buttercream uses hot sugar syrup poured into whipped egg whites, then butter is added; it is also very stable and less likely to separate.

Cream cheese frosting combines cream cheese, butter, and powdered sugar. It is tangier and softer than American buttercream and requires refrigeration sooner. If you are unsure which type you made, look at the ingredients: if cream cheese is in the list, treat it as cream cheese frosting and refrigerate within 2 hours. Otherwise, it is likely American buttercream and can sit out longer.

Frequently Asked Questions

Can I refrigerate buttercream on a cake and then freeze it?

Yes. Frosted cakes freeze well for up to 2 months. Wrap the frosted cake in plastic wrap, then place it in a freezer bag or container. Thaw it in the refrigerator overnight before serving. The frosting may look slightly dull after thawing, but the taste and texture will be fine.

Why does my buttercream smell like the garlic I stored next to it?

Buttercream absorbs odors because it is mostly fat, and fat-soluble compounds from strong foods migrate into it. Always store buttercream in a sealed container away from onions, garlic, fish, and other pungent foods. If this has already happened, the frosting is still safe to eat but will taste off — you may want to discard it.

Is it safe to use buttercream that has been in the fridge for 3 weeks?

It depends on storage conditions and whether you see signs of spoilage. If it looks normal, smells normal, and was stored in a sealed container at a consistent temperature, it is likely safe, but the texture and flavor will have declined. When in doubt, discard it — buttercream is inexpensive to remake.

Can I re-beat separated buttercream and use it again?

Often yes. Let separated buttercream come to room temperature, then beat it with an electric mixer for 2 to 3 minutes. The emulsion usually reforms and the frosting becomes smooth again. If it does not smooth out after beating, or if it has been refrigerated for more than 2 weeks, discard it.

Does homemade buttercream last as long as store-bought?

Homemade buttercream made with fresh butter and real ingredients lasts about as long as store-bought, roughly 2 weeks. Store-bought frosting often contains preservatives and stabilizers that extend shelf life to 3 to 4 weeks, but homemade is fresher-tasting and worth the shorter storage window.