The Type Of Cake That Will Benefit From The Refrigerator's Moisture
You've probably heard that you should never store your cake in the refrigerator because it will dry it out. And, this is true for most cakes because the cold temperatures of the refrigerator cause the fats in the dessert, like butter, to become solid and dense. Those temperatures can also lead the starches in flour, which are broken down during the baking process, to recrystallize, thus making the baked good in question more likely to get stale.
But there is one kind of cake that is safe to refrigerate: a high-ratio cake. In fact, these cakes might even benefit from the cold air.
Because high-ratio cakes, like pound cakes and sponge cakes, are quite moist due to their high sugar content, which is typically equal to or more than their amount of flour, they have a tendency to go bad when stored at room temperature in an airtight container.
The refrigerator provides the perfect balance
Though storing at room temperature in an airtight container is the correct method of storage for almost any other type of cake, warmer temperatures can create a breeding ground for bacteria for this already wet cake, especially if wrapped tightly in plastic.
High-ratio cakes are typically made with high-ratio cake flour because it can absorb more sugar and liquid than all-purpose flour. Meanwhile, the high-sugar content of the cake keeps it from going stale as quickly as the average cake as it absorbs water from the surrounding air.
As the sugar takes on liquid over time, it is important that it is stored in the refrigerator to reduce the risk of mold — or slow the process of mold growth at the very least. Because the refrigerator dries out regular cakes, it is actually the perfect place for a high-ratio cake because it is causing evaporation just as the cake self-moistens.