I'd been worrying about my sourdough starter, because after four days it hadn't really done anything. Then, overnight, it woke up and bubbled and frothed. So I fed it according to the directions for the last stage of a "seed culture" in Reinhart's Whole Grain Breads. It woke up even more, and had nearly doubled by 6:00 yesterday evening. So I put 100g of it in my King Arthur Flour sourdough crock, and fed it 200g each of flour and water.
And Frankenstein's monster awoke!
Three hours later, it had more than doubled, and was nearly at the top of the crock. So I stirred it to degas it, and left it. Shortly before midnight, I checked in on it, and it had more than doubled again, and had overflowed slightly. I cleaned up, degassed it again, and left it. About 2:30 in the morning, I looked in on it again, and it had grown so much that it overflowed and made a sizeable (and very gooey) puddle on the counter! I cleaned up again, discarded some of it, and left it, and this morning it had once again grown nearly to the top of the crock. I discarded all but 100g, and gave it a 1:1:1 feeding, and so far it hasn't (yet) gone mad.
Is this normal? Was this because it's a young starter, and thus overactive? Or is it contaminated with something that makes it go into overdrive?