Originally Posted by Sweetly Baked
When I see a recipe in a cookbook and it says this will serve 12 people, how do I scale it for 100 people for a wedding cake. According to wilton website a party cake serving size is bigger than wedding cake serving size, shall I assume that the recipe in the book is going by party size and convert it accordingly.
You don't have to assume anything.
Every cake recipe should tell you which sizes of pan to use, or it will tell you how much (weight or volume) batter it makes. If it doesn't tell you that extremely important information, DO NOT use it unless you want to do a test for your own comsumption.
The Wilton pages for wedding and party servings tell you the exact size of each serving, there is no assuming anything there. I personally find there is one deficiency with the Wilton charts: they give you smallish pieces of oval and some other odd shaped cakes. Those ends of rows look smaller than I would recommend to serve so I figure less pieces than the Wilton wedding chart for those shapes.
The Wilton wedding cake serving size is eight cubic inches, so you can scale any recipe that tells you it makes one 9" by 13" by 2" cake.
Area of a rectangle/square is height time width.
Area of a circle is pi times radius squared (pi times long radius times short radius for an oval). Remember that the radius is HALF the diameter.
And volume is area times depth.
I use an Excel table for scaling cake recipes. Once you make a column with the measurements for a "good" recipe (one that consistently gives you good results), then you simply make another column with each ingredient multiplied by any factor you like. I save these tables and print them out in large font to work from without fear of losing a precious recipe.
Once you have scaled a recipe on paper, be careful to look it over. You cannot always mix a very large batch the same as two medium sized batches. This aspect of scaling up is covered in cookbooks with wedding cake recipes, they explain how much batter to mix at one time very well.
Edited by BakingIrene - 12/10/12 at 7:36pm