Week 1: Angel Food Cake

Angel food cake is light, airy, and delicious. I love eating it with strawberries and whipped cream during the summer. Since strawberries come into season starting in June, and I had a freezer with 85+ egg whites in it from my lemon curd tests, I figured now was the perfect time to start working on this recipe!

Angel food cake has very few ingredients: flour, egg whites, sugar, salt, vanilla extract, and a strong acid (usually cream of tartar). Unlike most cakes, there are no leavening agents (baking soda/baking powder). This is because angel food cake gets its light, airy texture entirely from incorporating air into the egg whites in a meringue. This leads to some unusual deviations from typical cake baking. It has such a delicate structure that it needs to be cooled upside down or it will collapse under its own weight. Because of this, you want the cake to stick to the inside of the pan. Typically cake recipes call for a non-stick pan that is some combination of greased, floured, and/or lined with parchment paper. But for angel food cake, you want a pan without a non-stick coating and you do not line, grease, nor flour the pan. To get the cake out of the pan, it is helpful for your pan have a removable bottom (otherwise you'll have to get creative).

The basic technique for angel food cake seems simple enough: create a meringue with the acid, egg whites, and half of the sugar, add flavorings, and then fold in the flour and remaining sugar. Despite this, I have admittedly been intimidated to try angel food cake because there is so much lore about it online. People zealously argue over which stage to whip the meringue to, baking temperature, what type of sugar to use, and whether to add water or not. It can be head spinning, but I'm hoping to use the scientific method to make some sense of all these different methods as I work through this. I'm also going to have to be very careful to minimize the number of splits because I only have one angel food cake pan, and each cake needs several hours to cool in the pan.

As usual, I researched a number of recipes to see what trends I could find as a starting place. I broke each recipe down into percentages. I am not including the vanilla extract (usually 1-2 tsp.) and the salt (usually ~1/4 tsp.) in the breakdown since they only contribute to the flavor here rather than any of the chemical reactions. Some recipes also used almond extract, but that gives a different flavor profile, so I am going to stick with vanilla for now. I am going to use a standard of 1 tsp. of vanilla and 1/4 tsp. of Diamond Crystal kosher salt across the board.

Recipes broken down in percentages from [1], [2], [3], [4], [5]. Percentages don't include vanilla extract or salt.

We can see from these recipes that the relative quantities of ingredients are pretty tight, which indicates that there isn't much room to play around here. The recipes have ~42-47% egg white, 13-15% flour, and 37-43% sugar.

I decided to kick things off by trying Recipe 1 first. It was a disaster both in the execution and baking, but I learned quite a bit! Despite videos and recipes of people online folding the flour and remaining sugar directly into the stand mixer bowl they had whipped the meringue in, I quickly found that I needed a lot more space to work with. My mixer bowl started overflowing as I folded, getting meringue all over me and my workspace. Maybe someday, I can fold like a pro, but for folks like me, a nice big bowl to fold in the flour and sugar is incredibly helpful. I also learned that I can't fold ingredients anymore without quoting Schitt's Creek ("I don't know how to fold broken cheese like that!" ), so I have to apologize in advance to my husband who is going to hear this several times a week for the foreseeable future.

There are also a lot of suggestions of how to tell when an angel food cake is done baking. Some recipes called for using the toothpick test, so I went with that for this recipe since it was familiar. This was my biggest mistake. Most of the recipes I found called for 30-35 minutes of baking, but I baked for 37 minutes until I had a clean toothpick. When I went to release the cake from the pan after cooling, it was wet and soggy. It also had wet, eggy patches, and tasted completely of eggs in the parts that were cooked. It was so underbaked and raw in parts that I had to toss it for food safety. The method I now use for angel food cake is to press gently on the top of the cake in the part farthest away from the edges. If your finger leaves an imprint, it needs more time, but if it is firm and springs back, then it should be done. I found that the optimal bake time for my oven was actually 45-47 minutes, which is drastically more time than all the recipes called for. This is another reason why you shouldn't go on bake time alone but always test!

Next time, I will work toward finding my reference recipe to start testing. While the cake this week was largely inedible, I could tell from the few nibbles I had that it was sweet enough. Based on this, I am going to eliminate Recipe 2 because it has much more sugar, and I can tell that it will be far too sweet for me. I think it is still worth considering some aspects of Recipe 1 in future weeks as this failure was all on me, not the recipe itself. There is not a huge difference between Recipes 3 and 4 (except that Recipe 4 is behind a paywall and I cannot see it), so I will try out Recipe 3 next week alongside Recipe 5. Recipe 5 adds quite a bit of water, so it should be significantly different. Once I find my reference recipe, I am going to have to dig into different techniques before I start varying ingredients because these seem like they will have the largest influence on the final product. In future weeks, I will also go into more detail about what makes a meringue do its thing, so stay tuned!