Why does a cake sink as it cools?

Linda says: Help!!   I have been baking for over 40 years.  Lately, my cakes are sinking in the middle.  In the oven, the cakes rise great.  I do not open the door until timer goes off.  Then I check cakes for doneness with a tester.  The center comes out clean.  I proceed to take cake out of oven.  While cooling, it starts to sink.  What am I doing wrong?  My measurements of ingredients are exact.  I bought new baking soda & baking powder.  Still they sink.  I am baking for a bake sale on Saturday.  My shoofly pies sank some in the middle.  HELP!!!!

Baking S.O.S. says: It sounds like you have done everything right, so it is a complete mystery as to why your cakes suddenly started sinking when they never did before.

The only explanation I can think of might be if you oven is starting to bake inconsistently as it ages.  You could try putting an oven thermometer in the oven to check the actual temperate as it is baking. (Turn on the oven light to check the oven temp without opening the door.)

Another possibility might be if you are baking with a gas oven.  I learned recently from a service person that installed a new gas range at my workplace that the pressure through the gas lines can fluctuate quite a bit, especially in the colder months.  With the fluctuations in gas pressure comes fluctuations in baking temperature, and there is no way to control that, unfortunately.

The only suggestion I can give you is my own solution to the same problem that I was experiencing with my favorite cake recipe: I simply added a little baking powder to force the cake to rise up a little more.  The extra baking powder helped the cake to stay risen, even after removing it from the oven and cooling it.

I hope you can find a solution that will work for you.  Good luck!