How to : How to Thicken Frosting

Add more powdered sugar. Most frostings contain powdered sugar, or icing sugar, and the most common way to thicken a runny frosting is by gradually mixing in a bit more powdered sugar to offset the liquid ingredients. Sprinkle in 1 to 2 tbsp (15 to 30 mL) of powdered sugar at a time, then stir it in and check the consistency.^[5]

Mix in a bit of meringue powder alongside the powdered sugar. To cut down on the sweetness of powdered sugar, you can add meringue powder, as well. It will thicken your frosting without contributing any sweetness of its own.^[6]

Use tapioca, cornstarch, or arrowroot starch. Dry starches like these absorb liquid and are a great way to thicken frosting without altering the taste of the frosting. Add roughly 1 tbsp (15 ml) of starch to your frosting. Heat the frosting over low heat, if it can withstand higher temperatures, while stirring the starch in. Remove from the stove as soon as the frosting begins to thicken.^[7]

Add more cocoa powder if you’re making chocolate frosting. While this is not an option for vanilla, cream cheese, or other non-chocolate frostings, the addition of more cocoa powder is worth trying if you are making a chocolate frosting. Add more cocoa powder into the frosting 1 to 2 tsp (5 to 10 ml) at a time. Otherwise, you may end up with frosting that is too thick or too potent. Since cocoa powder is also fairly bitter on its own, too much can also cause the frosting to become bitter.^[8]

Mix in some gelatin to avoid flavoring your frosting. If you don’t want to add any sweetness to your frosting, pour a flavorless gelatin packet into warm or cold water. When the gelatin has dissolved, pour it bit by bit into your frosting, stirring continuously, until your mixture thickens.^[9]

Add in some shredded coconut to enhance the flavor. If you’re already making coconut icing, you can add more in to thicken up your mixture. Add at least 6 g (1/4 cup) of shredded coconut to your frosting, then fold it in with a spatula.^[10]

Use flour for cooked frostings. If you are making warm frosting on your stovetop, you can try thickening a runny frosting with a bit of flour. Sprinkle 1 tsp to 1 Tbsp (5 ml to 15 ml) of flour into the frosting and stir over low heat on the stove until it begins to thicken. Remove it from the stovetop and keep stirring until the frosting cools down.^[11]

Try softened cream cheese. If your frosting is too sweet as well as being too runny, you can try adding cream cheese to it as a way to thicken the consistency and add a contrasting tanginess to the existing sweetness. Add about 1 oz (30 ml) of cream cheese to your frosting and blend it in well.^[12]

Mix in more butter or shortening. For frostings that use butter or shortening, using more of either ingredient can help thicken frosting that is a little too runny. Add 1 tbsp (15 mL) or so at a time to prevent distorting the taste and consistency too drastically.^[13]

Consider mixing in a dash of heavy cream. For frostings that can stand to be beaten and chilled, heavy cream is another way you can thicken the consistency without making the taste too sweet. Add about 1/4 cup (60 ml) heavy cream to the frosting and beat it well to combine your ingredients.^[14]

Use marshmallow fluff if you’re making marshmallow buttercream. Marshmallow fluff is the perfect blend between sticky and fluffy, so it can help bind your ingredients together. If you’ve already put some in your frosting, add 1 to 2 tbsp (15 to 30 mL) more, then fold it in with a spatula.^[15]

Measure your wet ingredients carefully. Even a teaspoon too much heavy cream can make your ganache runny and inconsistent. As you put together your frosting, use measuring cups carefully to avoid any mistakes.^[16]

Use heavy cream or whipping cream. While most recipes call for this, it’s easy to think that you can substitute them for regular milk. However, normal cow’s milk doesn’t have enough fat to thicken ganache, so you might end up with watered down frosting instead of a thick and creamy one.^[17]

Find a recipe based on the chocolate you’re using. White chocolate is different from milk chocolate, and milk chocolate is different from dark chocolate. Make sure you’re reading off a recipe that lines up with what chocolate you’re using to avoid a runny outcome.^[18]

Throw in a handful of chopped chocolate if your ganache is too thin. While your ganache is still warm, chop up some more chocolate (the same kind that you already used) and throw it into the bowl. Stir the chocolate in with a spatula to let it melt and combine to thicken up your mixture.^[19]

Follow the instructions closely. Frosting might seem simple, but making even a minor change to the ingredients can result in an unexpected change to the consistency. Make sure you’re using the right ingredients at the right measurements to make your frosting perfect.^[20]

Mix in the liquid ingredients last. Typically, the fully liquid ingredients in frosting are added last. Following this procedure could help you to prevent runny frosting before it happens.^[21]

Add ingredients slowly and in small amounts. One of the biggest reasons why people often end up with consistency problems while making frosting is simply that a little too much of one ingredient gets added, throwing the entire recipe off. Both the liquids and powdered sugar need to be added slowly and in small amounts. If a frosting ends up being way too thick at first, the need to thin it by adding more liquid can result in the addition of too much liquid, which will make the frosting too thin.^[22]