I was inspired to make this cake because my dear friend Christine gave me lots of purple yams when she came to visit me a couple weeks ago. If you haven't had purple yams before, you must! You'll be blown away when you taste them since they are naturally super sweet like candy. Only buy small sized yams though. The big ones are not very sweet and spoils easily.
What is Chiffon Cake? Chiffon cake is a simple cake made from four base ingredients, oil, eggs, sugar, and flour. Leavening agents such as baking soda and powder is not used or needed to create volume because whipped eggs are the leavening agents. In order for eggs to maintain is volume, sugar is needed to stabilize and to create structure in the whipped eggs.
Taste: As you have guessed, this chiffon cake is unlike any other because it contains purple yam, making it sweet and tasty.
Texture: This cake is light and fluffy from air whipped into the eggs. When I pressed down on the cake to flatten, it bounced back up. This chiffon cake has great volume but less compared to those made of cake flour.
My Results: I am very happy with my purple yam chiffon cake but I have room to improve. The top of my cake deflated a little, making it dense compared to the rest of the cake (in the photo, the top of the cake is the bottom because I flipped the cake upside down). It was still tasty but I want the same volume throughout the cake. The color of my cake did not come out purplish pink but bluish-grey. I believe the color of my cake was due to the quality of my yams. I used large yams and they didn't have the super dark rich purple color as the small ones.
Modification: I used whole wheat pastry flour instead of cake flour, and I decrease the amount of sugar because purple yams are very sweet. When I make this next time, I will use less sugar and use small sized yams since they are sweeter, more flavorful, and has a richer purple color. I adjusted the amount of eggs used to make it easier for people like me who don't want to weigh the amount of eggs needed.
Ingredients to make an 8" cake
This recipe is inspired from a recipe by Noriko Ozawa.
90 grams mashed purple yam*
5 egg yolks
oil
water
12 grams lemon juice
80 grams whole wheat pastry flour
5 egg whites
80 grams (1/3 cup + 2 teaspoons) sugar
10 grams cornstarch
*choose small purple yams to make this cake.
Method
1. Wash and wrap the purple yams in foil. Bake at 350F for 30-45minutes or until fully baked. Too check for doneness, slide a knife into the center of the yam. The knife should slide easily in and out. Slice the yam in half. The yam should be moist and have a dark rich purple color. If it doesn't, it might not be fully cooked. If it appears dry and there is not much color, the yam may be not good. Once cooked, mash the yams well.
2. Preheat oven to 325F. Use a tubed shaped cake pan. There is no need to grease the tube pan. You can use a ceramic dish or cake pan but the cake will deflate a bit and not have as great of volume. Prepare the ceramic dish or pan by lightly greasing the bottom or line it with parchment paper.
3. In a medium bowl, sieve flour. Set aside.
4. Place egg yolks, water, and the mashed sweet potato in a mixing bowl. Whisk the mixture to combine. The color of the batter will not be purple.
5. Add the oil and stir to combine. Now add the lemon juice and stir to combine. The lemon juice will bring color back to the mixture. It may be a pink color. Sieve the flour into the wet mixture and whisk until it is fully incorporated. The mixture should be smooth. Add the small amount of sugar. Stir to combine.
6. In a clean dry bowl, beat the egg whites with an electric mixer on the lowest speed. Once it becomes frothy and foamy, turn the speed on high and add the sugar to the whites gradually. Add 1 tablespoon of sugar at a time. Before adding the last tablespoon of sugar to the egg whites, combine it with the cornstarch. Beat the egg whites until the whites appear smooth and glossy. When the whisk is lifted up, the peak of the whites will curl and droop slightly.
- Something wrong happened to my egg whites when I added the cornstarch became it became more like a batter. I beat my whites with the whisk until I reached a ribbom stage. That is when I could draw an 8 with the batter. The 8 would disappear after a few seconds.
7. To combine the two mixtures together, add the egg whites into the yam batter in three different parts. First, add a third of the whites into the yam batter. Use a spatula to fold the batters together. Do this by cutting through the center of the batter and lifting the bottom of the batter to the top. Turn the bowl a quarter turn after each fold to evenly blend the two mixtures together. When the whites are combined with the yam batter, add half of the remaining eggs white, and use the folding method to combine. Repeat this method with the remaining whites.
8. Pour batter into pan and lightly tap it against the counter to release unstable air bubbles. Bake in a pre-heated oven at 325F for 45 minutes. I tinted my cake so the top won't burn. I could have let the top browned a bit more though. if a skewer comes out clean after being inserted into the center of the cake, it is done.
9. Remove the cake from the oven and let it cool upside down. By cooling it upside down, the springy texture of the cake is maintained. This isn't possible if it is baked in a ceramic pan. Unmound cake after its cooled.
10. Remove the cake by running a thin knife around the side and center of the tubed pan. If your cake pan does not have a removable bottom. Try to loosen the bottom of the cake with a thin spatula. With the removable bottom tubed ban, push bottom to separate the two pan pieces. Then run knife between the pan and bottom of the cake. Flip cake over to a serving plate and enjoy.
Texture: This cake is light and fluffy from air whipped into the eggs. When I pressed down on the cake to flatten, it bounced back up. This chiffon cake has great volume but less compared to those made of cake flour.
My Results: I am very happy with my purple yam chiffon cake but I have room to improve. The top of my cake deflated a little, making it dense compared to the rest of the cake (in the photo, the top of the cake is the bottom because I flipped the cake upside down). It was still tasty but I want the same volume throughout the cake. The color of my cake did not come out purplish pink but bluish-grey. I believe the color of my cake was due to the quality of my yams. I used large yams and they didn't have the super dark rich purple color as the small ones.
Modification: I used whole wheat pastry flour instead of cake flour, and I decrease the amount of sugar because purple yams are very sweet. When I make this next time, I will use less sugar and use small sized yams since they are sweeter, more flavorful, and has a richer purple color. I adjusted the amount of eggs used to make it easier for people like me who don't want to weigh the amount of eggs needed.
This recipe is inspired from a recipe by Noriko Ozawa.
90 grams mashed purple yam*
5 egg yolks
oil
water
12 grams lemon juice
80 grams whole wheat pastry flour
5 egg whites
80 grams (1/3 cup + 2 teaspoons) sugar
10 grams cornstarch
*choose small purple yams to make this cake.
Method
1. Wash and wrap the purple yams in foil. Bake at 350F for 30-45minutes or until fully baked. Too check for doneness, slide a knife into the center of the yam. The knife should slide easily in and out. Slice the yam in half. The yam should be moist and have a dark rich purple color. If it doesn't, it might not be fully cooked. If it appears dry and there is not much color, the yam may be not good. Once cooked, mash the yams well.
2. Preheat oven to 325F. Use a tubed shaped cake pan. There is no need to grease the tube pan. You can use a ceramic dish or cake pan but the cake will deflate a bit and not have as great of volume. Prepare the ceramic dish or pan by lightly greasing the bottom or line it with parchment paper.
3. In a medium bowl, sieve flour. Set aside.
4. Place egg yolks, water, and the mashed sweet potato in a mixing bowl. Whisk the mixture to combine. The color of the batter will not be purple.
5. Add the oil and stir to combine. Now add the lemon juice and stir to combine. The lemon juice will bring color back to the mixture. It may be a pink color. Sieve the flour into the wet mixture and whisk until it is fully incorporated. The mixture should be smooth. Add the small amount of sugar. Stir to combine.
6. In a clean dry bowl, beat the egg whites with an electric mixer on the lowest speed. Once it becomes frothy and foamy, turn the speed on high and add the sugar to the whites gradually. Add 1 tablespoon of sugar at a time. Before adding the last tablespoon of sugar to the egg whites, combine it with the cornstarch. Beat the egg whites until the whites appear smooth and glossy. When the whisk is lifted up, the peak of the whites will curl and droop slightly.
- Something wrong happened to my egg whites when I added the cornstarch became it became more like a batter. I beat my whites with the whisk until I reached a ribbom stage. That is when I could draw an 8 with the batter. The 8 would disappear after a few seconds.
7. To combine the two mixtures together, add the egg whites into the yam batter in three different parts. First, add a third of the whites into the yam batter. Use a spatula to fold the batters together. Do this by cutting through the center of the batter and lifting the bottom of the batter to the top. Turn the bowl a quarter turn after each fold to evenly blend the two mixtures together. When the whites are combined with the yam batter, add half of the remaining eggs white, and use the folding method to combine. Repeat this method with the remaining whites.
8. Pour batter into pan and lightly tap it against the counter to release unstable air bubbles. Bake in a pre-heated oven at 325F for 45 minutes. I tinted my cake so the top won't burn. I could have let the top browned a bit more though. if a skewer comes out clean after being inserted into the center of the cake, it is done.
9. Remove the cake from the oven and let it cool upside down. By cooling it upside down, the springy texture of the cake is maintained. This isn't possible if it is baked in a ceramic pan. Unmound cake after its cooled.
10. Remove the cake by running a thin knife around the side and center of the tubed pan. If your cake pan does not have a removable bottom. Try to loosen the bottom of the cake with a thin spatula. With the removable bottom tubed ban, push bottom to separate the two pan pieces. Then run knife between the pan and bottom of the cake. Flip cake over to a serving plate and enjoy.
Yay! Hope it tasted as good as it looks! I'll get the smaller yams next time! Sowee...
ReplyDeleteThanks for the yams, really! The cake was really good!
ReplyDeleteWhat is the measurement of oil and water?
ReplyDeleteI can't believe I forgot to add the measurements! So sorry!
DeleteOil- 70g
Water- 80g
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