How do products have ‘secret recipes’ if they need to disclose the contents on the packaging?

Question

How do products have ‘secret recipes’ if they need to disclose the contents on the packaging?

In:

Answer 1

If your ingredients are “eggs milk butter and flour sugar”, there are different ways they can be combined, in different proportions and different orders and with different techniques, that you can get different results.

It’s like saying “if all cars are basically just pistons gears and tires why is a Bugatti different from a Ford?”