Wheat starter behaving strangely - rising and collapsing two times per feeding!
Over the last few days I've been checking the activity of my wheat starter (100 % hydration) in a somewhat different manner than I'm used to. I've kept it in room temp the last three days (I normally keep it refrigerated and feed it once a week when I am not baking, which I usually do about 1-2 times per week) and I've been feeding it according to what most people generally seem to recommend here on TFL: every 12 hours with a 1:2:2 ratio (starter:water:flour). The feedings consist of a low protein wheat flour (10 % protein) and regular tap water (no additives). However, during this period I've been noticing some rather strange things...
My starter usually doubles (200 %) in size in about 4-4.5 hours. But then, a while after it reaches its first peak, it collapses a bit and levels out at maybe 150-175 % of its original volume, at the same time creating a small cluster of soapy bubbles at the center of its surface. But then, a couple of hours later, it rises AGAIN, and finally when its been active for a total of about 8-10 hours it levels out at around 200 % (or more). Some short time after this second peak it finally collapses down to its original size. It never tripples in size or anything, as I've been reading that others starters do here on TFL
Now, I haven't really read anything earlier on TFL that describes this scenario. Is anyone else experiencing this kind of starter behaviour? Also, when would you recommend using the starter for baking (or feeding) - at its first peak or at its second?
Thanks in advance for all your help!