Advice on converting a yeast recipe to a sourdough + yeast recipe?
I have a country milk loaf recipe that uses instant yeast. I tried converting it into a pure sourdough recipe (keeping the recipe's original hydration, just removing the instant yeast and adding about 20% in levain and compensating for the additional flour and water coming from the levain), but found that the sourdough changed the flavor and texture too much. The bread came out with a mild tang and a more open crumb. These aren't bad things in and of themselves, but I'd love to stay as true to the recipe's original flavor and texture as possible — milky, slightly sweet, and with a beautiful tight crumb.
Does anyone have a baker's percentage for using both sourdough and instant yeast in a recipe?
Ideally I'd love to have this loaf naturally leavened, but not to the point where the sourdough changes the flavor of the bread. I suspect 20% levain was too high for this goal. Could I reduce the percentage of my levain, and add just a little bit of instant yeast to help boost fermentation? Does anybody have a recommended bakers percentage for this?
Recipe is below in case that helps. Thank you!
Flour - 100%
Water - 37.5%
Milk - 29.38%
Olive oil - 9.38%
Salt - 2.25%
Yeast - 0.13%