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How to Fix Runny Icing (And Avoid It)

Cake icings that are made with egg whites, like 7-minute icing and white mountain icing, are a little tricky to get just right and can easily be too runny. The primary issues are that the eggs sometimes don’t beat up light and fluffy, and the sugar and water are not cooked long enough.

To fix runny icing, add a little bit of powdered sugar to it and re-mix. Keep adding small amounts of the confectioner’s sugar until it is at an acceptable firmness. Just keep in mind that it may not be as light and fluffy as desired, but it will still spread fine and taste great.

To avoid runny icing, be sure to let the eggs sit out for at least 30 minutes to reach room temperature before beating them. The most reliable way to make sure the sugar and water are cooked for the exact length of time is to use a good candy thermometer and cook the ingredients to 234℉.

Now, let’s dive a little deeper into the details and hopefully avoid this happening in the future.

Closeup of a bowl of icing with a mixer

Fixing Runny Icing

Unfortunately, there are not a lot of options when it comes to fixing 7-minute or white mountain icing made from egg whites.

If your batch of icing refuses to get firm enough to spread on the cake after you have beaten the egg whites until they are fluffy and have cooked the sugar and water until it threads, the only option I am aware of is to add just enough confectioner’s sugar to add a little firmness to the icing and get it to a spreadable texture.

Related 12 Easy Ways to Fix Runny Frosting.

What Causes Runny Icing? 

There are two main causes of runny icing:

  1. The egg whites didn’t beat up light and fluffy. This could be caused by not letting the egg whites have time to come to room temperature before beating or if it is raining or the humidity is very high.
  2. The sugar and water were not cooked long enough. If the sugar and water were not cooked to the “threading” stage, then the icing would not become firm.

How To Avoid Runny Icing

Be sure to do these three things to avoid runny icing:

  1. Allow time for the eggs to come to room temperature before beating them.
  2. Avoid trying to make this type of icing when it is either raining, or the humidity is excessively high. (Yes, the weather does affect certain things that are cooked, as strange as it may sound.)
  3. Cook the sugar and water until it reaches the “threading stage” or 234℉.

I hope this has been helpful.

Thanks for stoppin’ by!

Jelly Grandma

For more, don’t miss How to Fix Undercooked Cake (That Is Too Moist).