When a cake rises during baking and then falls flat afterward, it can be frustrating and disappointing. There are several possible reasons why this might happen:
Underbaking: If the cake is taken out of the oven before it's fully baked, the structure may not have had enough time to set properly. As a result, it rises during baking but then collapses as it cools down.
Overleavening: Using too much leavening agent, such as baking powder or baking soda, can cause the cake to rise excessively during baking. Once it's out of the oven, the structure may not be strong enough to support the inflated volume, leading to a collapse.
Opening the oven too early: Opening the oven door during baking can cause a sudden drop in temperature inside, which can interrupt the rising process and lead to a collapsed cake.
Incorrect oven temperature: If the oven temperature is too high, the cake may rise too quickly, forming a weak structure that cannot maintain its shape once it cools down.
Overmixing: Overmixing the batter can lead to the development of too much gluten, resulting in a dense and heavy cake that may rise and then sink after baking.
Ingredient proportions: An incorrect ratio of ingredients, such as too much liquid or too little flour, can lead to an unstable cake structure and cause it to fall flat.
Old or expired leavening agents: Baking powder and baking soda can lose their effectiveness over time. If they are old or expired, they may not provide enough leavening power to support the cake's rise.
High altitude baking: If you live at a high altitude, adjustments may be needed in the recipe to account for the lower air pressure, which can affect the rising and baking times.
To avoid a cake falling flat after rising, make sure to follow the recipe carefully, measure ingredients accurately, use fresh leavening agents, and avoid opening the oven door until the cake is mostly set. Additionally, check your oven's temperature accuracy and consider making adjustments for high-altitude baking if necessary. If you've done everything correctly, but the issue persists, it may be worth experimenting with minor adjustments to the recipe or seeking advice from experienced bakers.