How do I strengthen my starter?
11 days ago I started two starters according to the directions here on TFL with rye flour and pineapple juice. The only difference between them is that I added the smallest pinch of commercial yeast to one starter, because if the "natural" starter failed I still wanted to have something to "play with" in the end.
I have fed both starters equally. I did three days of rye flour and pineapple juice, and then switched to unbleached AP flour and bottled spring water. I still have them on the countertop, feeding them twice daily with AP flour and water. Around the 5th or 6th day I dosed the natural starter with a small amount of vinegar to try to invigorate it.
From the beginning, the yeasted starter has been very vigorous. It has lots of large bubbles, definitely makes hooch, and has a very sour smell. I have no doubt that it can leaven at this point, though I understand that I'm probably propogating the commercial strain of yeast with it, not the "wild yeast" that we aim for.
The "natural starter" has been far more sluggish. It has only a few, small bubbles. It does make a small amount of less alcoholic smelling liquid, and it is clearly increasing in volume. It has a lovely sour smell. I know it's alive, but it is not very strong. It doesn't double and I don't think it could leaven anything yet.
I tasted a small amount of both starters, and the natural starter had a pleasant, clean sour taste. The yeasted starter was more sour, less pleasant. So I don't want to give up on the natural starter yet--I think it will make delicious bread someday . . . perhaps.
Is there anything I can do to invigorate the natural starter? Should I give it some more rye feedings to try to increase the wild yeasts that came from the rye flour? Is there anything else I can do to make this a viable leavening for sourdough?