For the most part, traditional sourdough bread is made with just 3 simple ingredients; flour, salt and water. So if the bread in question is the traditional simple sourdough bread, then it it is definitely vegan friendly.
Enriched Sourdough Bread Could have Non-Vegan Ingredients The list should have only 3 or 4 ingredients: – Flour – Water – Sourdough Starter (made of flour and water) – Salt
Sweeteners are sometimes added to sourdough breads for 2 reasons. 1. Gives the sourdough bread a boost of energy that helps give it extra rising power. 2. Sweetens the flavor of the sourdough bread and gives it less of a sour taste.