levain lost lustre
I have been following the Tartine instructions for many months now... with steadily improving results.
Now suddenly, my levain doesn't reach the point of passing the float test any more. Both my starter culture (fed daily) and the levain itself are reliably rising in a few hours. However, now the levain stops rising before it has enough entrained gas to float. This is a new phenomenon... until two weeks ago it would just keep rising until it passed the float test.
I thought I'd try, this morning, using the levain even though it's not passing the float test, and the oven spring was definitely sub-par.
I think I'm tasting more acidity in the levain than before, not unpleasantly so, but a noticable citrus note.
In case it might be relevant, the change does correlate with my moving from N.Cal to N.E. Oregon. But I know, too, that correlation and causality aren't the same thing!
Does anyone have any ideas what might be the cause?
Thanks in advance for any insight you may have to offer.