Converting cake tin sizes, ingredients amounts and number of people for sponge cake

A recent comment posted on the blog has inspired me to introduce an important topic: the baker’s math to work out the correct cake tin size for the required amount of people and ingredients for sponge cake (Italian pan di Spagna).

For a professional, understanding the ratio of eggs to the number of people or the diameter of the cake tin is a matter of course, but it can be a real head-scratcher for someone approaching the world of pastry.

Let’s see some important parameters first:

• The measurements here refer to average height sponge cake:

If you want to make a 15 cm tall cake the cake tin/ingredients amounts ratio changes considerably.

• The number of people is intended on an average serving of a cake filled with cream or fruit: the serving size usually is 100-150 g per person.
• These amounts refer to Italian sponge cake made with whole eggs & according to standard baker’s maths

The chart below offers a summary of ratios of cake tin sizes to number of people and ingredients amounts for sponge cake in grammes (eggs too)

N.B. Cornstarch can be used instead of starch.

CHART

I hope this was helpful; I want to emphasise again that “pastry-making is an exact science” and therefore conversions and balancing of ingredients cannot be done instinctively or in a “just-about” way, but they must be weighted scrupulously.

Have a good dessert!

If you are interested in exploring the topic of quantities I recommend this reading:

Il manuale delle quantità