LEVAIN Question why do you add to your fed starter

Hi! I didn’t realize I had to make a levain using fed starter. Tonight I prepared my “levain” using unfed starter and the flour+yeast+sugar. Will it be ok to use for dinner rolls tomorrow evening?

Well, it gets confusing. A starter that you have fed is not actually a starter- it's technically a levain, and ready to use. A starter is where yeast sort of exists in limited numbers in between uses. If you simply use the starter, you won't have as many little yeasties to do the work of rising, at least not within the time frame of this recipe. By creating the levain, as written, you provide the yeast in your starter the food to begin reproducing themselves in greater numbers. Then when you add in the rest of the ingredients, there is enough already present to do the task of rising the dough in the amount of time given in the recipe. Recipes that use unfed starter either require a full day of time to rise, or will have you add in additional dry yeast. The tang in a sourdough loaf is related to the amount of acetic and lactic acid produced by your yeast, and how long it was given or required to proof. In this recipe, there isn't a lot of time required for that- except for that overnight stage of prepping the levain. Think of your starter as where your yeast starts life, as a baby- and the levain as the mature adult yeast ready to take on work. Not quite how it works exactly, but a little easier to envision the difference maybe. As far as bacterial activity- the yeast will do that job without sugar at all. The sugar is just a bit of freebie to jump start the reproduction process, and make the rolls brown a bit prettier, as well as taste good.

You can certainly just use your starter, but the resulting rolls might be sourer. Adding sugar to the levain helps suppress bacterial activity in your starter to push the role more toward a mild flavor with only a hint of tang at the end.