Stella Parks is the brains behind the BraveTart blog and cookbook, former pastry chef, and Pastry Wizard at Serious Eats. When I wondered how best to store the leftovers from my carrot sheet cake and keep them tasting fresh, she's who I turned to for advice.
Ever wondered whether cake needs to be refrigerated? Or how best to keep it from drying out? Stella gives us (and you!) all the answers.
Stella's advice works for any kind of cake: layer cake, sheet cake, pound cake, quick breads, and even cupcakes. We'll break it down into into frosted and unfrosted, cut and uncut cakes, and then take a look at when refrigeration might be necessary.
Unfrosted and Uncut Cakes
Wrap these tightly in plastic wrap, top, sides, and bottoms, so the plastic is touching the sides of the cake (that is to say, don't just drape the plastic over the top). Second to this, go for a plastic zip-top bag. Store these wrapped cakes on the counter at room temperature, and they'll keep for about a week before starting to stale on you. Oil-based cakes tend to keep a day or two longer than butter-based ones. To keep cakes for longer than a week, try freezing them.
Learn how: Freeze Pre-Baked Cakes
Frosted and Uncut Cake
The frosting actually acts like plastic wrap here, protecting the cake from air and moisture in the environment. A frosted cake can be kept at room temperature for four to five days. Cover it with a cake keeper or an overturned bowl to protect it from dust, pet hair, and other things in the air (plastic wrap isn't necessary and would smoosh up the lovely frosting). Parks says that she actually keeps her frosted cakes in the microwave!
Cut Cake, Frosted or Unfrosted
Parks says to think of sliced cake as a living organism. As soon as you make a cut, moisture begins to escape and cause the cake stale more quickly. If you can, cover the sliced edges with more frosting to protect the cake from moisture loss. Otherwise, press a piece of plastic wrap directly onto the sliced side and make sure it sticks. Then proceed with covering and storing the cake as for the uncut version. Cut cake keeps for a little less time, about three to four days at room temperature.
When to Refrigerate Cakes
Most cakes, both frosted and unfrosted, cut and uncut, are perfectly fine at room temperature for several days. Refrigeration is only necessary if your kitchen gets very hot during the day (as Parks says, "High moisture + high sugar + high temp = bacteria feeding frenzy"), if you're making a cake that won't be served for more than three days, or when cake includes a fresh fruit filling or topping, or whipped cream frosting.
To refrigerate, wrap unfrosted cakes in plastic to protect it from absorbing any weird fridge smells and to protect it from drying out, and then unwrap it to warm up on the counter before serving. For frosted cakes, chill the cake uncovered for 15 minutes to harden the icing, then wrap it in plastic wrap.