Hi Sylvia, well, I can't really explain why your starter stopped rising with the Unbleached All-Purpose flour, but it may just need a little more time to adapt to its new feeding routine. I have 4 starters that are fed entirely with AP flour, and they continue to thrive, so there's nothing about this type of flour that makes it prohibitive for starter maintenance. On the other hand, if your starter was doing well with 90% AP flour and 10% WW, I don't see any harm in continuing to maintain your starter in this way. It will function essentially the same as a white flour starter, but may ferment a bit faster. 

If your kitchen is getting cooler this time a year, particularly overnight, this may also be contributing to the slow down in rising you've noticed. If you happened to have adjusted the ratio of ingredients in your starter to slow things down when the weather was warmer, now might be a good time to return to the 1:1:1 ratio we generally recommend, as long as you're still able to replenish your starter when it's at its peak. 

Try to be patient and trust that your starter is established enough so that it should rebound and return to rising predictably soon. 

Barb

• Reply