I have made Alice Medrich's Strawberry Celebration Cake (chocolate Genoise) from her book "Bittersweet" twice with great success. However, the recipe is for an eight-inch cake and I need to make a nine-inch cake. Reading a 2011 post on this site where a reader wanted to know about using 9" pans for a cheesecake recipe that calls for 8" pans, in one answer you suggested that the bake should increase the recipe by 25% and in a further post, an increase of 21% is suggested.
Any help or suggestions you offer will be appreciated,
Thanks,
Rene
...approaching the question geometrically, the 9" pan has a surface area of 4.5 squared times pi and the 8" pan 4 squared times pi, so the ratio is about 126%-127%. I'm assuming the 2 pans have the same height.
Keiko's Cakes has a great cake pan conversion tool on her website:
https://keikos-cake.com/panconversion.html
To convert the recipe amounts for an 8-inch round cake to a 9-inch one you need to multiply every ingredient amount with the factor 1.27.
With Keiko's tool, you can convert round or square pans, in inches or centimeters. I use it often.
Karin
Thank you! This is awesome!
First find the area of the circle for each pan
1. Radius is half the distance of a circle.
2. Square the radius (multiply the number by itself)
3. Multiple radius squared by pi
4. Pi is 3.14
Radius of 9" pan
9 ÷ 2 = 4.5
Radius squared
4.5 x 4.5 = 20.25
Multiply radius squared by pi (3.14)
20.25 x 3.14 = 63.58
The area of the 9" pan is approximately 63.5"
/////////
Radius of 8" pan
8 ÷ 2 = 4
Radius squared
4 x 4 = 16
Multiply radius squared by pi (3.14)
16 x 3.14 = 50.24
The area of the 8" pan is approximately 50"
////////
Now calculate the difference in percentage between the two pans.
Divide the area of the larger pan by the area of the smaller pan.
Area of 9" pan = 63.5
Area of 8" pan = 50
63.5 ÷ 50 = 1.27
You need to increase the recipe by 27%.