If you are mid-recipe with a baked cake on the counter and realize you have run out of butter, the immediate question is whether cooking oil can step in. The direct culinary answer is: no, liquid oil cannot make traditional American buttercream. However, several pantry staples can create delicious, silky frostings without butter.
Can you use oil instead of butter in frosting?
No, liquid vegetable oil cannot replace butter in classic buttercream frosting. Buttercream relies on solid saturated fats that form a crystalline matrix when whipped with powdered sugar, trapping air to create volume and structure. Liquid oil remains completely fluid at room temperature; beating oil with powdered sugar produces an oily, runny paste or separated greasy soup. Instead, use solid coconut oil, chocolate ganache, or cream cheese glaze.
Why liquid oil fails in buttercream
Understanding why liquid oil fails reveals the physical role butter plays in confections:
- The Saturated Fat Crystal Network: Butter contains roughly 65% saturated fatty acids. At kitchen room temperature (65°F–70°F / 18°C–21°C), butter is a semi-solid plastic emulsion. When beaten with an electric mixer, the solid butterfat crystals stretch and encapsulate millions of microscopic air bubbles while suspending fine confectioners’ sugar crystals.
- Liquid Oil Stays Completely Fluid: Vegetable oil, canola oil, sunflower oil, and olive oil consist primarily of unsaturated fatty acids with freezing points well below zero. They have zero solid crystal structure at room temperature. When whisked with powdered sugar, the sugar granules sink through the oil. The mixture cannot trap air bubbles, cannot hold stiff piping peaks, and will weep oil onto your cake layers.
4 Working frosting fixes when you have no butter
If you cannot make traditional buttercream, use one of these four tested frosting alternatives:
1. Solid Virgin Coconut Oil Frosting (Direct 1:1 Swap)
Coconut oil contains more saturated fat than butter (~90%) and sets completely solid at temperatures below 76°F (24°C).
- The Method: Measure virgin or refined coconut oil in its solid, scoopable state (like soft butter). Beat 1/2 cup (100 g) of solid coconut oil with 2 cups of confectioners’ sugar, 2 tablespoons of milk, and 1 teaspoon of vanilla extract until fluffy.
- Result: Pipes clean rosettes and sets firm upon chilling. Refined coconut oil has a completely neutral flavor, while unrefined virgin coconut oil adds subtle tropical aroma. Learn more in our coconut oil to butter guide.
2. Rich Chocolate Ganache (Cream or Milk + Chocolate)
Ganache requires no butter whatsoever. The cocoa butter naturally present in chocolate provides the required solid fat structure.
- The Ratio: Chop 8 oz (225 g) of semi-sweet or dark chocolate. Heat 8 oz (1 cup / 240 ml) of heavy whipping cream until steaming (do not boil), pour over the chopped chocolate, let sit for 3 minutes, then whisk until glossy.
- For Piping: Chill the ganache in the refrigerator for 45 minutes until firm, then whip with a hand mixer for 2 minutes into an airy, decadent chocolate fudge frosting.
3. Classic Cooked Milk Frosting (Ermine Frosting)
Ermine frosting (the original frosting used on 19th-century red velvet cakes) uses a cooked flour-milk pudding base.
- The Method: Whisk 3 tablespoons of all-purpose flour into 1 cup of milk and cook over medium heat until thickened into paste. Cool completely to room temperature.
- The Fat: While traditional Ermine incorporates softened butter, you can whip the cooled paste with solid vegetable shortening or refined coconut oil for a 100% dairy-free, silky finish.
4. Simple Powdered Sugar Glaze (Quickest Fix)
If you only need a sweet topping for a bundt cake, carrot cake, or banana bread loaf:
- The Formula: Whisk 1½ cups of sifted confectioners’ sugar with 2 to 3 tablespoons of warm milk, fresh lemon juice, or orange juice. Add a drop of vanilla extract and a pinch of salt.
- Application: Drizzle slowly over the completely cooled cake. The glaze dries to a shiny, crackly shell within 15 minutes.
Summary: What to do when a recipe calls for butter
| Frosting Style | Can You Use Liquid Oil? | Recommended Non-Butter Alternative |
|---|---|---|
| Vanilla Buttercream | No (turns into oily paste) | Solid refined coconut oil (1:1 volume swap) |
| Chocolate Fudge Frosting | No (separates) | Two-ingredient chocolate ganache (chocolate + cream) |
| Cream Cheese Frosting | No (will weep water and oil) | Full-fat cream cheese + powdered sugar + heavy cream |
| Bundt Cake Glaze | Yes (1 tsp oil adds gloss) | Powdered sugar + milk + vanilla (optional 1 tsp oil) |
For other substitutions in your cake recipe, see our complete guide to replacing butter with oil in baking or convert specific ingredient weights with our butter to oil converter.