I have just relocated to San Francisco, and in keeping with the spirit of the place (plus my graduation to a kitchen larger than a closet) tried my hand with sourdough starter. I'm using Peter Reinhart's 4-day procedure (using first pineapple juice and coarse rye, then water and KAF bread dough). By day 4, a Friday, after giving the seed culture an additional feeding because it seemed pretty inactive, I got enough of a rise to move to the "barm" stage. What he writes is that I should then expect a significant rise in a 6-hour window, what I got 12 hours later was .... pretty much nothing more than some bubbles. I put the barm in the refrigerator at this stage because I was heading out for the weekend, and today (Monday) what I see is the same volume with a lot of bubbles in it. Can anyone give me tips on how to turn this into something resembling a lively starter/barm? What am I doing wrong? Here are few things that might be influencing the outcome:

-My apartment is at about 68 degrees most days. I put the seed culture on day 4 into the oven with the light on to see if this speeded up activity (it did, some) but otherwise let it grow in the open air. I also kept the barm in the oven for the first 12 hours for the same reason.

-I have used a 2-liter container, which increased the surface area of the starter

-I only used plastic utensils

-My timing was generally good, but during that last rise after moving to the barm stage, I only checked the barm up until about 4 hours, then again at 12 hours (I had to get some sleep!).

Thanks so much. I really don't want to throw this out and start again as I'm optimistic that the bubbles = activity, I just want to perk up this rather sluggish barm! Right now it's residing in the refrigerator.

Mike now-in-SF