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I have someone asking me for a wedding cake. She wants three separate round cakes. The cakes will serve 100-150 people and the point she emphasized was it being easy to slice and share. Would two 11x3 inch cakes weigh 4 kg? I haven't baked large cake before so I'm not sure about the weight. I usually use a simple vanilla cake recipe for the base and cream cheese for the icing. Here is the recipe in case it matters:

4 eggs
1 and 1/2 cups sugar
1 cup oil
1 cup buttermilk
2 and 1/2 cups flour
2 and 1/2 tsp baking powder
1 tsp baking soda
1 tsp vanilla powder

Gigili
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    "*I haven't baked large cake before*" Conventional wisdom says that you're going to need to make this recipe *at least* once before the main production run. You need to be sure that the recipe scales, that your oven can take it, that it will turn out well, etc. As part of that preparation you can also weight the end result and estimate how many you'll need. –  May 16 '16 at 10:51
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    There's a point at which baking a larger than normal cake is problematic. 11" might be okay, but I know I had a hell of a time the first time I made a 14". (it took hours before the middle set (I reduced temp to prevent burning outside); I ended up torting it and putting it on sheet pans). See my answer at http://cooking.stackexchange.com/a/27516/67 . Also, there are tables out there w/ the amount of batter to use per pan. Wilton's moved theirs but I found another at http://fatdaddios.com/help/cake-batter-serving-charts . (they say an 11"x3" requires 13.25 cups of batter and serves 47) – Joe May 16 '16 at 15:28
  • @Stephie : sorry, my place of work has policies against online chatting. – Joe May 16 '16 at 15:46
  • That comment of yours helped me enormously, thanks a lot. @Joe – Gigili May 17 '16 at 08:03

4 Answers4

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It is a question of scaling.

  • In chat you told us the given recipe was for a 23 cm pan.
  • I'll ignore height for now, assuming the same height for all pan sizes, because that can be adjusted in a second step.

The math:

  • The cake batter for round cakes fills a cylinder.
  • The volume of which is base circle area x height, ignore height as stated above.
  • The formula of a circle is pi x r2. As pi is constant, ignore it.
  • So for scaling, you only need to look at the radius (1/2 diameter) of the pans - or even the diameters.

Divide the desired diameter (or radius) by the original one and square the result.

-> Use that value to multiply all ingredients.

Further adjustments:

Height scales linear - for a cake that is 1.5 times as high as the original, you need 1.5 times the batter etc.

So for your question:

To go from a 23cm / 9in cake to a 28cm / 11in cake,
you need (28/23)2 = 1.48 times the original recipe.

My personal gut feeling: three of those won't feed 100-150 guests.

Stephie
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  • @Jolenealaska As Steeve said: not all cakes recipes are equal and this works independently. If you know how many servings the original recipe is, up-/downscaling works the same way. – Stephie May 16 '16 at 10:37
  • Eggs are the one ingredient that is a pain to measure in other than units. So, I want to know how many servings the original recipe makes. Then it's just coming at it from the other direction. – Jolenealaska May 16 '16 at 10:39
  • @Jolenealaska I'm waiting for Gigili's input, but a 9inch cake is - in my experience - ca. 12 servings. – Stephie May 16 '16 at 10:42
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An experienced cake baker friend of mine suggests one egg per five guests when making sponge wedding cakes like chocolate or vanilla (not traditional Buritsh fruit cakes, which is the norm where I come from)

I'm in the same boat, of cooking my first wedding cake for 150 guests, and I'll be making a 30-egg cake on that basis.

Steve Cooper
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You are asking about weight. A cake pretty much weighs the same as the sum of its ingredients (maybe some slightly evaporation from the buttermilk). There are plenty of free cup to gram converters on the internet, just use one of those to get an idea how close you are to your 4 kg goal. An egg weighs about 60 - 80 g, but it depends on the size.

Marianne013
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    Your egg weight seems a bit off - most baking recipes use size M or perhaps L, which, after removing the shell gives you 50-60g. – Stephie May 16 '16 at 11:36
  • @Stephie : I've always been told to assume large eggs unless the recipes specifies otherwise. (60 grams (2.125 oz), w/ shell). Some of the classic textbooks (eg, Fannie Farmer, Joy of Cooking, Gourmet) will have a section at the beginning on how they handle measurements ... unfortunately, most of the celebrity chef ones these days don't. – Joe May 16 '16 at 15:32
  • @Joe which sans shell will get you exactly in the range I mentioned... For calculating the weight of the batter, the shell weight should subtracted. – Stephie May 16 '16 at 15:37
  • Pro bakers avoid the confusion by just using grams for eggs. Normally, 50g is a medium egg, so it may be more appropriate to talk about 1kg eggs or 1.5kg eggs. – Steve Cooper May 16 '16 at 16:39
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    @Joe Large in the US = Medium in Europe, so you're both really saying the same thing. – Catija May 16 '16 at 19:23
  • @Catija : the sizing is different? crap, something else to add to the [translating 'question'](http://cooking.stackexchange.com/q/784/67). – Joe May 16 '16 at 20:08
  • @Joe Yep! There's a couple of answers that explain it [here](http://cooking.stackexchange.com/questions/3705/converting-between-egg-sizes). – Catija May 16 '16 at 20:10
  • I actually weigh my eggs for all the classic sponge cakes which (when it comes down to it) ask for equal amounts of butter/sugar/flour and eggs. There are definitely 80g eggs on sale in Britain. – Marianne013 Jun 01 '16 at 10:12
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So, here's is what I did:

I did calculate the volume of the cake pan I wanted to use (37 x 5 cm) and the one the recipe calls for (23 x 4 cm), thanks to @Stephie's answer. From the ratio, I figured how much batter is needed to fill the 37 cm cake pan. As for the baking of the large cake, I did take @Joe's advice, used an old towel and a tin can opened from both sides in place of flower nail. The other point @Joe mentioned was longer baking time in lower temperature, I usually bake the cake of the original recipe for 35 minutes in 180 C so I reduced the temperature to 150 and baked the large cake for 50-55 minutes. It turned out just like the small cakes. enter image description here

Gigili
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