Q. I purchased a sourdough bread starter that is accustomed to white flour but I’d like to use whole wheat flour. How do I switch the sourdough bread starter over to whole wheat flour?
A. All of our sourdough bread starters can be converted to be used with a wide variety of flours. We recommend that you initially activate the starter and establish the starter with whatever type of flour it is accustomed to (generally white, wheat or rye flour). Once the sourdough starter is clearly healthy (bubbling happily) and has gone through at least a week of regular feedings, split the sourdough starter in two and put half in a safe place in the refrigerator. Start feeding the second half with the new flour. Within a few days/feedings, the sourdough starter will be fully converted. This method of splitting the sourdough starter allows you to convert the sourdough bread starter over to a new flour type but also gives you a back up in the refrigerator as there can be a learning curve when working with new flour types.
Please note, the best flours for feeding sourdough are white flour, whole wheat, spelt and rye. Brown rice flour can be used but starters fed with brown rice starter tend to be less robust and require more regular feedings (minimum 2-3 times a week).