Prevent Soggy Cakes With Epsom Salt
If you need to pre-bake the cake for a particular function, chances are the crust will be slightly damp by the time you serve it. Luckily, pastry chef Stella Parks has an incredibly elegant solution: magnesium sulfate.
Chances are, you are more or less familiar with magnesium sulfate. If you have visited any number of chemical laboratories, you know that this is the substance that lines the desiccator and prevents your reagents from absorbing water. (You also remember the “desiccator” as that terrible expensive thing that you would have broken if you hadn’t moved the top in the right direction.) If you haven’t been to chemistry labs, you probably knew about magnesium sulfate as a “bathtub.” salts “or” epsom salts “.
As in chemical laboratories, magnesium sulfate absorbs water from the environment, and we can use this to benefit the crusts of the pie everywhere. This is a fairly straightforward process. First, take some unscented Epsom salt and dry it completely. (Parks walks you through the process at the link below.) When they are dry, transfer them to an airtight container and place the chilled cake (on its plate) right on top of the salts to keep it in place. as fresh as possible until it gets to a picnic (or company party, or wherever heck).