By sam83 Updated 24 Jun 2013 , 5:30pm by sam83

sam83 Posted 24 Jun 2013 , 7:17am
post #1 of 9

AHi everyone

I was wondering if someone could help, please. I made a chocolate cake at the weekend and it tasted great, now my friend would like me to make it for her birthday. The only problem is, the cake I made was in a 20cm round cake tin and she would like her BD cake in a 10 inch square cake and I have NO idea how to scale the cake ingredients up. The recipe I used is below.

200g good quality dark chocolate, about 60% cocoa solids 200g butter 1 tbsp instant coffee granules 85g self-raising flour 85g plain flour ¼ tsp bicarbonate of soda 200g light muscovado sugar 200g golden caster sugar 25g cocoa powder 3 medium eggs 75ml buttermilk

If anyone could help I would really really appreciate it.

8 replies
mmmmmmmmcake1954 Posted 24 Jun 2013 , 9:50am
post #2 of 9

Hi Sam83,

I can't remember where I found this equation, but this is how I scale my recipes up and down using the pi calculation method, then the percentage has to be applied to each of the ingredients, it has always worked for me.  Hope this helps.

Equation used to scale up recipe for round cake tins   eg:   to scale a recipe for a 10" round 3" deep cake tin that takes 2 hours to cook to say a 14" round 4" deep use the following equation:   usual recipe:   pi  x  radius squared  x  height  = volume 22/7 x 5 x 5 x 3 = 235.7 cubic inches   required size:  pi  x  radius squared  x  height  = volume 22/7 x 7 x 7 x 4  =  661 cubic inches   To scale the 10" recipe to fit the 14" to fit the 14" tin: 616 divided by 235.7 = 2.6 i.e. All ingredients need to be multiplied by 2.6

{Cooking time will either increase or decrease}

The area of a circle =    Pi is always the same formula 22/7  (3.14159)  X   The square of the length of the radius   x   Height (for cake tin)

mmmmmmmmcake1954 Posted 24 Jun 2013 , 9:58am
post #3 of 9

Hi Sam83, sorry just realised it didn't copy and paste all the instructions, I will try again.

Equation used to scale up recipe for round cake tins   eg:   to scale a recipe for a 10" round 3" deep cake tin that takes 2 hours to cook to say a 14" round 4" deep use the following equation:   usual recipe:   pi  x  radius squared  x  height  = volume 22/7 x 5 x 5 x 3 = 235.7 cubic inches   required size:  pi  x  radius squared  x  height  = volume 22/7 x 7 x 7 x 4  =  661 cubic inches   To scale the 10" recipe to fit the 14" to fit the 14" tin: 616 divided by 235.7 = 2.6 i.e. All ingredients need to be multiplied by 2.6 cooking time should be approx:  2 hrs x 2.6 =  5.2hrs     The area of a circle =    Pi is always the same formula 22/7  (3.14159)  X   The square of the length of the radius   x   Height (for cake tin)

mmmmmmmmcake1954 Posted 24 Jun 2013 , 10:00am
post #4 of 9

Hi Sam83,  Ignore the cooking time you will have to judge that yourself, but I hope that this helps you.

remnant3333 Posted 24 Jun 2013 , 12:25pm
post #5 of 9

You can always make 1 and 1/2 of the recipe then fill your pans from 1/2 to 2/3 full of batter. If you cook 2 layers you probably would not have that much left over.  If you have leftover batter, you could always make an extra small layer or cupcakes and freeze it in your freezer for no less than one month. From what people say here, you can not tell the difference once it is thawed out if wrapped and stored properly.

I really don't remember too much concerning all that math stuff I learned in high school. My brain doesn't work the way it used to. LOL!!!

yortma Posted 24 Jun 2013 , 1:30pm
post #6 of 9

PAN AREAS (in square inches)

SQUARE

8"           64

9"           81

10 "        100

12"         144

16”         256

RECTANGLE

9 x 12      108

11 x 15    165

12 x 18     216

ROUNDS

6"            28.25

8"            50.25

9"            63.5

10"          78.5

12"          113

14”          154

2 6"         56.5

2 8"         100.5

2 9"         127

2 10"       157

2 12"       226

HEX

6”             23.5

9”             52.5

12”           93.5

15’           146

18”           210.5

I keep this in my recipe binder.  It shows the relative difference in size of the various pans, and the relative amounts of batter needed.   The actual volume would be the areas multiplied by the height, but assuming the height of the new layer(s) will be the same, it works fine to just look at the areas.  Start by thinking of what pan or pans the recipe in question is already known to fill.  Your recipe is for a 20 cm pan, which is an 8 " pan.  The area is 50 square inches.  A 10" square pane is 100 square inches, exactly twice as much.  If your original recipe made 2  20 cm layers, the same recipe will fill a 10" square pan once.  Most people only have one 10" square pan anyway, so just make your usual recipe and fill the 10 " pan once, and then make it a second time to get 2 layers if that's what you need.  If you have 2 10" pans and want 2 layers,  double your original recipe and make 2 10" layers at the same time.

If your original recipe made just one 8" layer, then double it to make one 10" layer that will be the same height.

HTH

LizzieAylett Posted 24 Jun 2013 , 1:34pm
post #7 of 9

It is hard to add 2.6 of an egg, or whatever, so when I need to scale a recipe, I divide all the amounts by the number of eggs ( so in your original recipe I would divide everything by three) to get my base amounts, and then multiply back up (for example, to make 5 eggs' worth of batter).  That way you're only ever working with whole eggs, although it does make some other ingredients a bit more fiddly...

sam83 Posted 24 Jun 2013 , 5:30pm
post #8 of 9

AThank you all so much for the great advice. This forum is fantastic and everybody is so polite and helpful.

Remnant3333 I know the feeling but I'm thinking of investing in a calculator LOL

Thank you again for the advice it has been such a big help.

sam83 Posted 24 Jun 2013 , 5:30pm
post #9 of 9

AThank you all so much for the great advice. This forum is fantastic and everybody is so polite and helpful.

Remnant3333 I know the feeling but I'm thinking of investing in a calculator LOL

Thank you again for the advice it has been such a big help.