Excessive dusting of flour causes grey streaks in the crumb
A common mistake beginner baker make when baking sourdough bread is to dust their dough excessively with flour to prevent it from sticking. Although it works to prevent sticking, consistently dusting the dough with flour throughout the baking process can significantly change the hydration level of the dough, resulting in a denser and drier crumb when baked.
The greying of the crust and crumb happens when these raw flour from dusting is not incorporated into the dough. The excess flour is very dry as it has very little time to fully hydrate, and when it accumulates in the seams of our dough, it turns into grey streaks when it is baked.
Excessive flour can accumulate in our dough whenever we have to handle the dough particularly during folding and shaping.
Remember to dust off any excessive flour from the surface of the dough before you incorporate your folds, and the same precaution should be taken when shaping the dough. Otherwise, raw flour will be stucked in the seams to produce a grey tint on your crumb.
Baking with a small proportion of rye flour produces a grey tint
Sourdough bread made with a small proportion of rye flour in combination with white flour produces a dull greyish tint. The grey tint comes from the combination of the whitish color of white flour and the dark color of rye flour.
Is the greyish color bad for sourdough bread?
You will get grey streaks across the crumb and sometimes the crust of the baked loaf when you do not dust off the excess flour before folding and shaping.
This grey coloration is made of raw flour that is not well hydrated and they give off a bland taste with a dry texture; when there is too much raw flour in your dough from excessive dusting, the taste and texture suffers. The grey streaks are also visually unappealing, but it is safe to eat!
When baking with rye flour, rest assured as getting a consistently grey tint throughout the crumb of the baked loaf is perfectly normal and the grey coloration does not affect the baked loaf in any other way other than its visual appeal. If you would like your sourdough bread to be as white and clean in color, do not use any rye flour in your dough.
How to prevent dough from sticking without dusting with flour?
Dusting with flour is not the best method to prevent wet and sticky dough from sticking to your work surfaces and hands.
I have written a detailed guide on the preferred methods that professional bakers use to prevent dough from sticking. In general we want to minimize the use of any additional flour if we can help it, but in reality we can’t avoid dusting our dough with flour for some parts of the baking process such as when we are shaping the dough.
Read ‘Help! My Sourdough is Too Wet and Sticky’ ; the information is in the final heading of the article titled ‘How to prevent sourdough from sticking on your hands and baking surfaces?’.