Soda Is a Shockingly Good Egg Replacement for Boxed Cakes

I didn't know it until recently, but apparently boxed cake mixes are a popular store-bought ingredient to experiment with. Thanks to you, the good people reading my food hacks, I’ve been made aware of yet another ingredient that can masquerade as an egg in cake mix. Honestly, who needs eggs when you have soda?

Replacing eggs in baking can be tricky

Eggs continue to be unreasonably expensive, which is especially frustrating for a person like me who used to rely on them for most of my protein. I’ve made some adjustments, though, and now I try to use them only for the recipes that really require them. It might take a few failed attempts, but it's becoming easier and easier to identify when a recipe needs eggs, like a custardy Dutch baby, and when one can do without—like boxed cake mix.

I’ve tried plenty of egg replacement ingredients, like applesauce and bananas, in scratch cake mixes with varying degrees of success, and I’ve experimented with omitting the egg measurement from boxed cake mixes too. While the eggless boxed cake mix turns out just fine, in those tests I’ve continued to incorporate the water and oil measurement according to the directions. But as one reader let me know, you can make boxed cake mix with soda, not just as an egg replacement, but to replace the water and oil too.

Though I needed to test out this witchcraft, I could already see it working. While eggs typically provide binding, emulsification, and aeration to batters and doughs, commercial boxed cake mixes are designed to be foolproof. (It's almost like they knew we'd be cutting corners.) On my mission to turn boxed mix into black and white cookies, I found that cake mix refuses to change its consistency or texture. If liquid of any kind is added, whether it’s oil, water, soda, juice, or eggs, it will do its darndest to become fluffy cake.

However, I did wonder how using soda would affect the flavor and the texture of the cake, especially without oil or egg yolks (a tenderizer). 

Credit: Allie Chanthorn Reinmann

Soda outperforms juice

I decided to test out replacing the ingredients with two different liquids: a cola and a fruity juice. In my prior tests, I had omitted the eggs without replacing their volume or weight. I simply erased them from the game and the resulting cake was flatter than one with eggs, but tender and boasting that nostalgic boxed cake flavor. 

I did the same thing here, leaving out the eggs and replacing the water and oil measurement (a total of 12 ounces) with the juice and cola separately in two tests. I was actually impressed by how much better soda turned out to be than fruit juice. Even after thoroughly whisking, enough of the carbonation remained to lift up the batter so it had a nicer appearance compared to the pomegranate juice cupcake's fallen center.

Left: pomegranate juice cupcakes (surprise! they're brown). Right: cola cupcakes. Credit: Allie Chanthorn Reinmann

I used pomegranate juice thinking the fruit flavor would be a nice complement for the cake. Instead, it was a little too sweet (if you can imagine) and the fruit flavor became murky against the yellow cake. The soda however, was actually very tasty. Even though I’m not a soda person, I enjoyed it. This could be a good opportunity to get creative with soda and cake flavor pairings.

How to make boxed cake mix with soda

1. To make cake mix with soda, start by preheating the oven and getting the pans ready. Mixing the batter takes all of one minute. You need your pan and oven to be ready to go so you don't loose more carbonation than necessary.

2. Once your oven is preheated, simply empty out the dry boxed mix into a large mixing bowl. Look at the box's directions and add the measurement of the oil and water together. If the box says, "1 cup water and 1/2 cup oil" then you'll need 12 ounces (1 1/2 cups) of soda. Pour the soda into the bowl and whisk it all until well incorporated. Tiny bits may remain unmixed.

3. Pour the batter into your prepared pans immediately. Bake as directed on the package.

How does the texture hold up?

Despite the fallen centers on the pomegranate cupcakes, both cakes shared the same texture: light and fully aerated with a slight rubbery skin on the bottom. This likely manifested because of the lack of fat (a shortening agent because fats shorten gluten strands) from the missing oil and egg yolk. 

Credit: Allie Chanthorn Reinmann

That said, this texture difference is completely unnoticeable if you’re not looking for it. Any person who crushes a Fanta vanilla cake at a summer picnic is not going to comment on the lack of a shortening agent. I promise. Soda can and should be used as the wet ingredient for boxed cake mix. It’s a fun way to experiment with flavor combinations and while you’re at it, save a bit of money on eggs and oil too. Try orange soda, root beer, ginger beer, or dare to dream with Diet Coke the next time you make a batch of cupcakes.