## Percentages, ratios, an extra ingredients

I’m just learning baker’s percentages and the attendant ratios. I get the *flour, water, yeast, salt *ratio, but what about when you add other ingredients, specifically sugar, fat and eggs, and then things like potato flakes and dehydrated milk, and all those little goodies you add during the second knead. How do they figure in the baker’s percentage? Are they represented as a percent of the total flour? Are eggs part of the hydration (Do I figure the percent based on the flour, then subtract that weight from the total hydration)?

Here’s a formula I’m working on that illustrates my dilemma. It’s a recipe for *shokupan, *translated into a formula:

100% bread flour, 70% hydration, 1.6% salt, 1.6% yeast. The recipe also contains sugar, butter, and dried milk. Using the recipe, the sugar and butter each become 7% of the flour, and the dried milk figures out to 3.3%. The tangjhon (the starter) is 6.8% of the total flour, and 50% of the total water. Are those fairly common ratios for the “extra” ingredients?

i guess my question is if ingredients that are not the four essentials, how dou you figure them into the final formula?