What Is The Best Way To Store Buttercream? 

It’s OK to store the buttercream in an airtight container until you’re ready to use it if you’re planning to use the buttercream within a few days. 

If you don’t plan to use the buttercream within a few days, you may store it in the freezer.

To be safe, it is best to keep it frozen until you want to use it unless you plan to use it within a couple of weeks.

The buttercream may need to be defrosted at room temperature and maybe re-whipped to get the correct fluffy texture, depending on the consistency you prefer.

When kept at room temperature, how long does buttercream last? 

Following the addition of butter or milk to buttercream, it will keep for about three weeks if kept in an airtight container with a tightly fitted lid.

It is possible to preserve buttercream made with water for up to 6 weeks at room temperature provided it is properly packaged.

If you do not store it in an airtight container and instead opt to leave it out in a dish that is covered or in a cool, dry location after three days, it will begin to deteriorate.