Hello cakecentral

I'm a post grad photography student looking to make my way into the cake business as I've always had a passion for baking things, often bringing basic cakes and cupcakes into class just because I enjoy doing so. Now that Ive graduated I want to kick it up a gear and be more explorative with cakes.

My girlfriend and I are going to an orchestrated concert at the Royal Albert Hall in November and a large group of people who are also going are meeting up at Hyde Park beforehand for a picnic. I offered to the group to make a large wedding style cake for everyone to eat (it's hopefully going to feed around 150-200 people) but as I've only ever made 8" and 7" cakes out of my Be-Ro recipe book I have no idea how many ingredients to use for cakes that are 6, 8, 10 and 12 inches wide by 4 inches tall.

My 12" cake is going to be a chocolate one with the other three tiers being victoria sponge cakes (although I've heard that victoria sponge doesn't hold up to well as a stacked wedding cake and that I should do madeira but I've never made a madeira cake before)

The chocolate cake recipe I have is for an 8" cake:
200 g (7 oz)  Be-Ro Self Raising Flour
225 g (8 oz)  caster sugar
1 x 2.5 ml spoon (½ tsp)  salt
25 g (1 oz)  cocoa powder, sieved
100 g (4 oz)  margarine
2 medium  eggs
5 x 15 ml spoon (5 tbsp)  evaporated milk
5 x 15 ml spoon (5 tbsp)  water
few drops vanilla essence

Does anyone know how I could upgrade these ingredients (so to speak) so that I can get a 12" cake out of it?

My vanilla recipe is for a 7" cake:
100 g (4 oz)  margarine
100 g (4 oz)  caster sugar
2 medium  eggs
100 g (4 oz)  Be-Ro Self Raising Flour

Again does anyone know how I can add and take away ingredients to make 6", 8" and 10" versions? Or if anyone has their own recipes for those sized cakes that would also be really helpful

Sorry for the very long post but I wanted to be thorough so that you all understood what I was after. I look forward to hearing some replies

Before we get to your recipes, please plan this part: your four tier cake for 150-200 will weigh 20+ kilos and will require to be transported to the picnic somehow (no not on the tube). HOW do you plan to do this...

Tiered cakes require internal supports to keep the layers from collapsing into each other regardless of what type of cake you bake. PLEASE go to this link and read it several times:http://www.wilton.com/cakes/tiered-cakes/dowel-rod-construction.cfm

and then this one http://www.wilton.com/cakes/tiered-cakes/stacked-tiered-cake-construction.cfm

So finally for your recipes: It works best to bake the cakes 2" deep and sandwich them with icing to make 4" deep tiers. It would be best for you to purchase and use "magic cake strips" to eliminate the humps that would otherwise form on the tops and which would have to be cut off.

If we are speaking of all round tins, here is how they compare to your recipe sizes:

6" tin is 0.56 of the 8" tin

10" tin is 1.56 of the 8" tin

12" tin is 2.25 of the 8" tin

6" tin is 0.73 of the 7" tin

8" tin is 1.30 of the 7" tin

10" tin is 2.0 of the 7" tin

12" tin is 2.94 of the 7" tin

PLEASE go and calculate the recipes yourself from these numbers. Hint: you do NOT "add and take away" you MULTIPLY.

If you cannot do this to make yourself a shopping list, then I would advise you to NOT bake your first "business" cake for 150-200 people...

Here's a website another baker recommended. I've never used it, but hopefully this can help:

http://www.cakebaker.co.uk/baking-tin-size-conversion-calculator.html

Also, are you planning on stacking the cake, and have you ever stacked a cake before? If not, I'd recommend looking into that and practicing beforehand.

I have stacked a cake before when I helped my aunt to make a wedding cake so I understand that I need to use dowels between the layers. I will be putting the fondant on each individual cake and put in the dowling then transport them in separate boxes then once I am at the picnic I will stack them. Don't worry I have done my research into all of that, it was just the ingredients needed for the different sized cakes that I needed. Thanks for the advise, I will be sure to multiply all the ingredients correctly. I have plenty of time to plan seeing as the picnic isn't until November hence why I am getting organised now.

I'm sincerely glad that you have some exposure to stacked cakes. Too many people post on Cake Central without that much.

Doing the math is a good way to get in the habit of scaling up and down on paper first. I use Excel because you can total the ingredients as well as multiply/divide for each tier. Enter the ingredients in one column and then you can save the results for future reference.

Your recipes will scale up to the 3X required for the biggest tier. You can mix this 3X all at once, and make up several of the smaller cakes from the first mixing, and then the largest cake as a separate mixing. Don't let the batters sit around except in the cake pans.

I never thought of using Excel, that makes so much sense though. Will definitely do it like that
Just one last question, it may be silly but when I'm multiplying the ingredients when I get to things like the eggs for example (lets take the chocolate cake) you said the 12" tin is 2.25 of the 8" tin so times the 2 eggs in the original recipe by 2.25 = 4 and a half eggs. how would I do the half an egg? just use the egg white or the yolk? or would I round that up to 5 eggs?
Many thanks

With rounding eggs I tend to round down to the nearest whole egg and add a little water at the end to get the right consistency. Else I go by weight of egg and just have omelette for dinner

Sounds fab to me Thanks!

I posted this ages ago http://cakecentral.com/modules.php?name=Forums&file=viewtopic&t=743935&highlight=
Irene's advice is great, this post might help in the future though if you want to use your recipes in big sheet pans/ odd shaped tins.

I just downloaded the excel file, it's perfect! Thank you for putting the time into making that for people like me who have no clue ^_^ And yes Irene's advise was amazing as well. I'm so glad that I actually got some replies!

I haven't been online for a few days.

If you have a lot of "fractional" eggs to bake over a day or two, then just beat up a few and dole them out according to either weight or volume. Say the egg weighs 50 grams without the shell, then half an egg is 25 grams.

The remainder of the broken egg can be refrigerated overnight in a closed jar.l

Thats ok I thought of that the other night actually but thank you. Your help has been fantastic, all of you ^_^