Many times when the religious permisibility of alcohol is debated (especially in substances with small amounts of alcohol in it) people will claim that even bread has traces of alcohol. How valid is that claim? Is there a published survey of the amount of alcohol found in bread in general?
Baker's yeast is capable of fermentation, so it can certainly produce alcohol.
In 1926 it was reported in the Canadian Medical Association Journal that bread can contain between 0.04 and 1.9% of alcohol. This is just a short report, not a full scientific paper.
In "Ethanol Content of Various Foods and Soft Drinks and their Potential for Interference with a Breath-Alcohol Test" the alcohol content of certain kinds of bread are reported. The highest alcohol content is found in Rosemary's onion bread with 0.98%, and lower values for other kinds of breads.
So, bread certainly contains at least traces of ethanol, and possibly even rather significant amounts.
As an additional answer, some kinds of bread are treated with alcohol as a preservative. For example Italian pancarré (sliced sandwich bread) is very commonly laced with ethanol.
Type "0" wheat flour, water, lard (4.2%), dextrose (3.4%), salt, yeast, wheat malt extract. (Treated with ethyl alcohol).
Manufactured in a facility that also uses peanuts, tree nuts, milk, sesame, soy, eggs.
— translation of Pancarrè - Mulino Bianco