Angel Food Cake

20100821:
My goal in making Angel Food cake from scratch was to use the unused egg whites from the Coconut Creme Brulee. However, the angel food cake is really just part of the Frozen Pineapple Upside-Down Cake. I read two recipes from AllRecipes.com, Angel Food Cake III and Heavenly Angel Food Cake. They're pretty much the same in terms of ingredients and instructions, so I mainly followed the second recipe. Because the creme brulee only used 8 egg yolks, I scaled the recipe down to 8 eggs by multiplying the serving size by 2/3 and rounding down.

Both recipes (when scaled) called for the following:

1/2 cup and 2 tablespoons and 1 teaspoon flour
more or less 1 cup of some kind of sugar
8 egg whites
1 teaspoon vanilla extract
1 teaspoon cream of tartar
about a pinch of salt

I took precautions in fixing my mistakes by adding 1 egg white, 1/8 teaspoon vanilla extract, and another pinch of salt to the egg white mixture.

Both recipes called for a 10-inch tubed pan. But I figured since I was scaling the recipe, that I could use a 7 1/8-inch tube pan. This would have been okay had I had enough experience with how much the cake would rise: I was able to get all the batter into one mini tube pan, but I figured, the cake has to rise, and then it would overflow. So I split the batter over two pans. I should have just discarded some batter and went with one pan. You'll see what I mean when you see the pictures. (Perhaps 6 eggs and proportionate amount of all the other ingredients would have been fitting for a 7 1/8-inch tube pan)

Process:
I took the 1 cup of egg whites (8 egg whites) out of the refrigerator and let it stand at room temperature for 30 minutes.


I sifted 3/4 cup and 1 tablespoon confectioners' sugar together with 1/2 cup and 2 tablespoons and 1 teaspoon all-purpose flour three or four times and set it aside.

I added 1 teaspoon cream of tartar, 1 teaspoon vanilla extract and a pinch of salt to the egg whites.

I began beating with the electric mixer, gradually adding 1/2 cup and 2 tablespoons and 1 teaspoon sugar, and wasn't sure how I would tell when it was dissolved but just went with it.
When I got to the instructions that stiff peaks should form, I didn't understand, so I looked it up as the mixer was going and tried to fix any mistakes I thought I made. I cracked a new egg and added its egg white to the batter, putting the egg yolk away into the fridge. I also added 1/8 tsp cream of tartar and if I remember correctly, another pinch of salt.
Eventually, I achieved stiff peaks, or at least firm peaks.


I folded in the flour mixture, 1/2 of it first. Then the other 1/2 of it when the first half looked like it was well distributed.
I scooped the batter into the 7 1/8-inch tube pan as described in the introduction above, until splitting it over two 7 1/8-inch tube pans. D'oh! One consequence of this was the batter that clung to the side of the first pan might have caused problems with the rising of the cake. The other is the higher surface area to volume ratio, so the cooking time is shorter than the expected 40 minutes. Which of course I didn't realize until after 40 minutes.
I cut through the batter with a knife to remove air pockets.
I baked the two pans at 350 degrees F for 40 minutes. The room smelt delicious.
In the mean time, I cleaned up this mess:

When I opened the oven I poked the cakes and they sprung back, but at the same time I saw a lot of burnt cake, so even if they weren't done they were done.

I took the pans out to cool. After a couple minutes, I realized I had to invert them, so I took out two plates and turned the pans upside down. Though because they were burnt, it probably didn't matter. I let them cool for a while.


After some time, I poked at the shorter one and tried a taste test. Not bad. The centers were still usable as I had hoped.
I then correctly pried out the cakes onto the plates (using a table knife). The first time, I was afraid to go along the edge (because I was using a paring knife), so I cut the cake and that didn't help get it out (I had tried this on the shorter less usable cake). But when I was no longer afraid to go along the edge (because the table knife isn't sharp), I went along the center, and then back to the edge, then I went along the perimeter and made a prying motion. It slowly wiggled the entire cake off the pan. So I had one semi-good-looking cake and one shorter semi-good-looking cake with a piece missing.

Learned:
When it came time to understand what "stiff peaks" meant, I found a site which had a lot of information on what I needed: How to Beat Eggs. Below are main facts from the page which will come in handy next time I work with egg whites:

Egg whites should be separated when cold and whipped when at room temperature. Egg whites will beat when cold, but it has to be done longer, while at room temperature they beat faster with a great increase in volume, giving a finer texture

What to do with overbeaten egg whites: sometimes they can be rescued by adding an extra egg white and beating again. Stop when the egg white is just beaten. An extra one will not disturb your recipe proportions. But, it doesn't always work!

A trace of fat in the egg whites will greatly reduce their volume when whipped. Crack and separate the eggs, placing the whites in the clean, dry bowl. Do not have a trace of egg yolk remaining, as it contains fat. To get the yolk out, I use the corner of a paper towel or a piece of broken egg shell to sop it up or I start over again with a fresh batch of whites.
Also, make sure the egg beaters, bowl, and spatula are free of grease. To make sure, wipe the clean implements with lemon juice or white wine vinegar, rinse both in warm water, and then dry. Don't use plastic containers because they tend to absorb and retain fat even if washed.

Adding a small amount of acid, such as cream of tartar, lemon juice or vinegar, stabilizes egg whites and allows them to reach their full volume and stiffness. It does this by making the egg coagulate faster. For example, angelfood cake egg white foam has lemon juice or cream of tartar added as a stabilizer. The natural acid on the surface of a copper bowl achieves the same result, so don't add ANY acidic ungredient when using.

An acid is added at the beginning of beating, during Step #2, below, when the whites are just beginning to become frothy. As a rule of thumb, use 1/8 teaspoon cream of tartar per egg white or 1 teaspoon per cup of large egg whites (8 to 10). For meringues, use 1/8 teaspoon cream of tartar for each 2 egg whites. There is no exact substitute, but in general, 1/8 teaspoon cream of tartar = 1/4 teaspoon freshly squeezed lemon juice. You can add a pinch of salt for every 1 to 2 egg whites instead, but it has a lesser stabilizing effect.

The composition of the bowl in which you beat egg whites can make a big difference. A copper bowl reacts chemically with egg whites to form fluffy, high-rise whites - it contains an ion which reacts with an egg white protein, specifically conalbumin, to form a more stable foam and helps the whites retain moisture. The same result can be obtained using stainless steel or glass bowls with the addition of cream of tartar. However, I don't use a glass bowl because I have found that when using it, its naturally slick surface doesn't give much traction for the egg whites to climb the bowl.

Avoid plastic or wooden bowls because of their naturally porous surface which attracts grease because of its porous surface; grease or fat deflates egg whites. Never use aluminum which reacts with the egg whites causing them to turn slightly gray. If beating by hand, the mixing bowl should be 9 to 10 inches in diameter and 5 to 6 inches deep,

Size and shape of pans are crucial; they should allow for the proper expansion of the egg whites during baking. Angel food cakes are best baked in an ungreased tube pan with straight sides. That's so the whites can rise during baking. Because an angel food cake does not have a strong gluten structure or chemical leavening, it needs the pan sides to virtually cling to while baking. If greased, the egg whites would slip downwards, causing a flat cake.

The website is kind of all over the place when it comes to describing these steps. Nevertheless the general idea is to increase the speed from one step to the next. And I guess technically you can better control what ingredients to add throughout the different steps, but again, there's some decoding of instructions that would be required. I don't feel like decoding today. For now, the overall steps are Step #1 Raw Eggs, Step #2 Frothy or foamy, Step #3 Soft Peak Stage, Step #4 Firm Peak Stage, and Step #5 Stiff Peak Stage.


Result:
Apart from the slight burning on top, the center was delicious, and the bottom is in fact also delicious, even though I didn't use those portions in the Frozen Pineapple Upside-Down Cake. Hooray! I suppose if I had cream, I could have stacked the two back together, after slicing off some of the burnt cake. Also if I hadn't taken a bite to try how the cake turned out. Haha. But again my goals were achieved: I used up the egg whites and made enough tasty angel food cake to use in the Frozen Pineapple Upside-Down Cake. Note: in fact it worked out extra nicely, I had to use an extra egg white, and the Frozen Pineapple Upside-Down Cake recipe called for three egg yolks and two egg whites.

[20100822]