Difference between: pastry cream and buttercream

I’m on a (slow-going, years long, I’m-dragging-my-feet) mission to learn more about baking.

Let’s find out the difference between pastry cream and buttercream.

chocolate cupcakes with white frosting


  • Pastry cream: a creamy custard, often flavored, used as a filling for eclairs, flans, etc; also called pastry custard.
  • Buttercream: a vanilla-flavored cake frosting or filling made principally of softened butter and powdered sugar; a similar mixture used as a filling for bonbons or to flavor ice cream.

Pastry cream:

  • Is basically a custard.
  • Is used as a filling for baked goods, such as Boston cream pie.
  • Is made from milk, eggs, sugar, cornstarch, and usually vanilla.

Basically, it’s as the definition described it.

Buttercream is a bit more complex, with more varieties.


  • Can be used between layers of a cake as well as the outside.
  • Goes with butter-based, oil-based, or other types of cakes.
  • Can be piped for decorations.
  • Can be flavored with vanilla, chocolate, fruit, etc.

There are four categories of buttercream.

American buttercream: 

  • The traditional buttercream we’re all used to.
  • Also known as confectioners sugar icing.
  • Is super sweet and a bit gritty.
  • Is best for topping cakes because of the grittiness, but can be used as a filling.
  • Is not really cooked – just butter and powdered sugar beaten together with a touch of milk and vanilla.

French buttercream:

  • Is made from egg yolks, sugar syrup, and butter.
  • Is rich and silky.
  • Is light and fluffy.
  • Is the most delicate and will melt easily.

Swiss buttercream:

  • Is made from egg whites, light corn syrup, white sugar, and softened butter.
  • Is lighter than French buttercream.
  • Is not super-sweet like American buttercream.

Italian buttercream:

  • Is made from egg whites, sugar syrup, white sugar, and softened butter.
  • Sugar syrup is poured into beaten egg whites.
  • It’s easy to pour syrup too fast or slow into egg whites.
  • It’s easy to accidentally have the hot syrup cook the eggs (eggs are not heated).
  • Is more difficult to master than the others.

Both Swiss and Italian buttercreams are considered to be meringues, because they’re made with egg whites and sugar.

In conclusion, pastry cream is essentially a custard used as a filling inside desserts, while buttercream is used as a topping, for decorations (flowers, etc), and can be used in between layers of cakes. 

Pastry cream is pretty basic, although can be prepared with many different flavors. Buttercream is more elaborate, with four different categories; American buttercream is the most simple.

You can check out a breakdown of other cake toppings – cream cheese frosting, fondant, etc. – on Epicurious.com here.