There`s a little tricks on this..
you build your bakeries far abit from your populated places..
place a barn beside it..the villagers will only get food from the nearest barn..
You built a town .. with fields around it ..so the yield goes to the 1st barn that is given..
Then you build a far abit small town and starts to build the fields too ! cause you`ll need wheat later on..then you starts to build a barn ..with some bakeries around it..(DO NOT PLACE THE BARN TOO NEAR TO YOUR 1ST TOWN) den u slowly build houses around it..it should do the trick
i manage to get 2k bread in storage and have no problem maintain the supplies
Hope it helps