I bought some sourdough starter at the San Francisco airport
about a year ago. I have had a LOT of fun with it and the best
bread I have made is from this starter.
I don't use the bread machine though. I usually make it completely by
hand on a Saturday. The first rising is supposed to take about 4-6
hours. If I am in a hurry, I put it on the radiator (during winter) or
at 100 deg in my convection microwave oven (convection only).
Normally, I just mix it up before I go to bed on a Friday night and let
it sit on the counter until I wake up in the morning. Then I mix in
the rest of the flour and put it into "Pam'd" pans. I then let it rise
to three times its original size. This second rising is supposed to
take about 2-3 hours, but I usually let it go 4-8 Finally, I bake it
at 450 for 16 - 20 minutes depending on the size of the pans I use. I
like it to be just golden brown on the top.
But you say you want the bread to be VERY sour. I made some like that
once accidently, but I THINK I know what I did wrong (or right
depending on how you look at it.) I had not been tending to my starter
very well - I think I had let it sit for 2 months in the refrig without
doing the "pour off a cup and then add a cup of flour/water" routine,
so I was afraid that the starter might be severely weakened. But, I
figured that since bacteria are pretty tough to kill completely by not
feeding them, some of them would still be alive. Note that by this
time, the starter had gotten pretty - shall we say "rude" - it
definitely smelled like starter. So - even though the starter smelled
strong, I figured that that the bacteria were weak, so I used two or
three times what the recipe called for. Then, again because I figured
that the bacteria were weak, I let the first rising go ALL DAY on my
spot near the radiator that stays at about 100 deg. The resulting
bread was REALLY sour. I loved it. My wife hated it.
Bottom line is that the sourness is probably more a factor of how long
you let the bacteria work rather than the bacteria you use.
Also, the recipe which comes with the starter calls for 2 cups of
water, one cup of starter, 2 tsp ea salt & sugar, and eventually 7.5 - 8
cups of flour. I think that makes the dough TOO stiff. I just make
sure it is good and stiff without worring about forcing in all the
By the way, you might get the impression from this that I am not the
most fastidious guy when it comes to following recipes. My basic bread
recipe goes something like this: Throw two or three cups of flour and a
teaspoon or two of yeast into the machine. Add sweetener - honey or
sugar. Put in some wet stuff - fruit juice - a pureed zucchini - a
banana - water - whatever. Butter or oil turns out to be optional.
Then throw in a cup of oatmeal or some wheat germ or something
depending on your mood. Run the machine for a minute and look at the
glop. If it is too dry, add water and if it is too wet add flour. The
point of all these recipes is getting the dough to the right
consistency and that is more important than what the recipe calls for.
The rest of the stuff does not seem to matter.
I have the same approach to sourdough bread. If the bread is supposed
to rise for 4 hours, and I am going to be out, I let it rise for 8
hours. The little yeasts and bacterias don't seem to care much.