Some weeks back I checked out Ken Forkish's "Flour Water Salt Yeast" ebook from the local library, and began lurking on these forums. I have learned a great deal about bread from all of your expertise here.
I read the first part of the book and thought of trying his sourdough starter recipe, at vastly smaller portions. I think he suggests 500g each per feeding, which is crazy for a beginner--why on earth would you need so much when billions of these organisms can live in a teaspoon?
Anyway, using more like 150g each of whole wheat flour and water, it started off smelling like rotted onions (the leuconostocs, as I later learned), settling down to a mild glue-like odor by the second week after switching to an all AP flour diet. But the bubbling activity was always weak, and tasted only sour--not yeasty at all. I suspect that I started twice-daily feedings too soon, and diluted the small yeast population to near extinction. After weeks it was going nowhere, so I made pancakes with the discard, and looked for another recipe.
I was happy to find Debra Wink's pineapple juice solution, and especially appreciated the thorough explanation of biology and chemistry that came with it. This was a refreshing change from the popular notions about local yeast drifting in on the air and mysteriously finding a balance. She explained well how creating the acidic environment first could give the culture a head start.
Her recipe only adds, not discarding, for the first few days, which makes a lot of sense. Not having pineapple juice, I used some expired frozen apple juice concentrate (having similar acidity). Two tablespoons each of juice and whole wheat flour; add two more each the next day, and the next. After that, discard all but approx. 1/4c, adding equal weights of AP four and filtered water.
The smelly phase was neatly averted; I noticed a sour aroma and hooch formation after 3-4 days, and by 1 week it had a definite yeast taste, though still a kind of bland sour smell. There was a surprise around days 8-10, when it smelled exactly like fresh apples--this long after the apple juice has been diluted out. But the apple smell didn't last; shortly after, it took on a kind of fruity banana-like smell (with a hint of paint or glue), which it has had ever since.
With few exceptions, I have fed my starter once a day. This has made for plenty of discards to turn into banana bread, waffles and pancakes, but still seems like a lot of diluting the colony. Since the first few days, I had never seen the telltale layer of hooch that means the starter is starving. Could I go two days without feeding? Longer?
So I did an experiment--I started a child feeding in a separate jar, 25g starter + 25g each AP flour and water (total of 75g), and did not feed it for 10 days. I gave it an occasional stir, but that's it. I kept feeding my mother culture in the original jar once a day as always. My kitchen is around 65-70F most of the time.
After 7 days, the unfed culture still bubbled away happily, rising about 50% between stirrings. No hooch, no sharp acetone smell--still the same fruity sweet-and-sour fragrance, and a tangy sour beer-like taste.
Drawing off a spoonful of this aged mixture, I did a comparison of activity between it and my fed-daily mother culture.
Child: 20g aged (7 day) starter, 20g water, 20g AP flour (small jar)
Mother: 50g starter, 50g water, 50g AP flour (large jar)
Both appeared to rise identically, each gaining around 75% volume in their respective vessels. Similar bubble action, similar fruity aromas and sour tangy taste.
If an 8-day-old starter still bubbles up to a moderate rise, there must still be some food for the yeast and lactobacillus to eat. As long as they're not apparently starving, what's the advantage to dumping a trillion happy critters in the waffle iron? Why not let them multiply and become concentrated?
So I'm thinking of skipping the daily feedings, and will simply let the colony mature. It wouldn't hurt to feed it once a week at least, but I can't seem to make enough waffles with the discards to justify daily feeding regimen, even with only a few spoonfuls a day.
After 10 days without a feeding, stirring once or twice a day, the aged starter finally stopped rising, and had minimal bubbling. There was only about 2 tablespoons of it left, so I simply fed it (no discard) with equal weights of warm water and AP flour in the evening. The next morning, it had almost tripled in bulk, filling a 1-pint jar to the brim (but luckily not overflowing). This is the best rise I've ever seen from the culture!
Is there value in sticking to a daily (or twice daily) feeding schedule, when it may take up to 10 days for a single feeding to be depleted? Or is it better to allow the starter to age long enough for the food to be fully consumed, and to become more concentrated with beasties?