For the best sourdough starter (and I have failed at this several times) - I got on the King Arthur website
Day 1 - Combine 1 cup whole rye/pumpernickel or whole wheat flour with 1/2 cup cool water in a non-reactive container. Glass, crockery, stainless steel, or food-grade plastic all work fine for this. Make sure the container is large enough to hold your starter as it grows. Stir everything together thoroughly; make sure there's no dry flour anywhere. Cover the container loosely and let the mixture sit at warm room temperature for 24 hours
Day 2 - You may see no activity at all in the first 24 hours, or you may see a bit of growth or bubbling. Either way, discard half the starter (about 1/2 cup), and add to the remainder a scant 1 cup All-Purpose Flour, and 1/2 cup cool water (if your house is warm); or lukewarm water (if it's cold). Mix well, cover and let sit 24 hours on the counter
Day 3 - By the third day, you'll likely see some activity — bubbling; a fresh, fruity aroma, and some evidence of expansion. It's now time to begin two feedings daily, as evenly spaced as your schedule allows. For each feeding, measure out a generous 1/2 cup, once it's thoroughly stirred down. Discard any remaining starter. Add a scant 1 cup All-Purpose Flour, and 1/2 cup water to the starter. Mix the starter, flour, and water, cover, and let the mixture rest at room temperature for approximately 12 hours before repeating.
Day 4 - repeat day 3
Day 5 - the starter should have at least doubled in volume. You'll see lots of bubbles; there may be some little "rivulets" on the surface, full of finer bubbles. Also, the starter should have a tangy aroma — pleasingly acidic, but not overpowering. If your starter hasn't risen much and isn't showing lots of bubbles, repeat discarding and feeding every 12 hours on day 6, and day 7, if necessary — as long as it takes to create a vigorous (risen, bubbly) starter.
This recipe calls for initially whole grain flour as the wild yeast that gives sourdough starter its life is more likely to be found in the flora- and fauna-rich environment of a whole-grain flour than in all-purpose flour. What if all you have is all-purpose flour, no whole wheat? Go ahead and use all-purpose; you may find the starter simply takes a little longer to get going. Also, if you feed your starter on a long-term basis with anything other than the all-purpose flour called for here, it will probably look different (thicker or thinner, a different color) and act differently as well.
Day 1 - Combine 1 cup whole rye/pumpernickel or whole wheat flour with 1/2 cup cool water in a non-reactive container. Glass, crockery, stainless steel, or food-grade plastic all work fine for this. Make sure the container is large enough to hold your starter as it grows. Stir everything together thoroughly; make sure there's no dry flour anywhere. Cover the container loosely and let the mixture sit at warm room temperature for 24 hours
Day 2 - You may see no activity at all in the first 24 hours, or you may see a bit of growth or bubbling. Either way, discard half the starter (about 1/2 cup), and add to the remainder a scant 1 cup All-Purpose Flour, and 1/2 cup cool water (if your house is warm); or lukewarm water (if it's cold). Mix well, cover and let sit 24 hours on the counter
Day 3 - By the third day, you'll likely see some activity — bubbling; a fresh, fruity aroma, and some evidence of expansion. It's now time to begin two feedings daily, as evenly spaced as your schedule allows. For each feeding, measure out a generous 1/2 cup, once it's thoroughly stirred down. Discard any remaining starter. Add a scant 1 cup All-Purpose Flour, and 1/2 cup water to the starter. Mix the starter, flour, and water, cover, and let the mixture rest at room temperature for approximately 12 hours before repeating.
Day 4 - repeat day 3
Day 5 - the starter should have at least doubled in volume. You'll see lots of bubbles; there may be some little "rivulets" on the surface, full of finer bubbles. Also, the starter should have a tangy aroma — pleasingly acidic, but not overpowering. If your starter hasn't risen much and isn't showing lots of bubbles, repeat discarding and feeding every 12 hours on day 6, and day 7, if necessary — as long as it takes to create a vigorous (risen, bubbly) starter.
This recipe calls for initially whole grain flour as the wild yeast that gives sourdough starter its life is more likely to be found in the flora- and fauna-rich environment of a whole-grain flour than in all-purpose flour. What if all you have is all-purpose flour, no whole wheat? Go ahead and use all-purpose; you may find the starter simply takes a little longer to get going. Also, if you feed your starter on a long-term basis with anything other than the all-purpose flour called for here, it will probably look different (thicker or thinner, a different color) and act differently as well.