To cook with ratios, you need to work from mass (weight), not volume, when measuring ingredients. If you want to convert your own recipes, this chart will be invaluable.
Download this chart, plus the rest of grimoire as a PDF.
How is this useful?
Well, let’s say you need to scale up a cake recipe that’s written for a single 8-inch square to two 9-inch rounds. Using the pan volume chart, we know that the original volume was 1.9 liters and that we now have to cover 4.2 liters (2 x 2.1) for the two 9-inch round pans.
Let’s breathe through the math. First, get the scaling factor by dividing the target pans’ volume by the original pan’s volume. So 4.2 / 1.9 = 2.211. Assuming the recipe is converted to mass measures, all you have to do is multiply each ingredient’s weight by 2.211 to get the right amount for the larger pans.
(For all those moaning about the math, do remember that there’s a calculator built into any device on which you could possibly be reading this. All you need to do is type in numbers. Butch up!)
You can also use this to derive the ratios of your favorite recipes so that you can more effectively tinker with them. This requires somewhat more work but will be immediately obvious to anyone with arithmetic inclinations. The key is to pick an anchor ingredient, usually flour, to represent your highest common denominator that generates the fewest fractional ratios in the other ingredients.