I have collected a few notes over the years on getting more sour flavor. At the end you will note some recommendations for starters with more tang. Note, none of these comments are mine. They are ones I’ve harvested for my own use over the years.
Keep in mind that there are two classes of organisms in sourdough starter -
bacteria and yeasts. Yeasts make it rise, while the bacteria give it the
Higher temperatures favor the bacteria, while lower temperatures favor the
yeasts. So if you want more sour flavor, you actually would want to
increase the time and/or temps of your dough fermentation.
Also, you can greatly influence the characteristics of sourdough bread by
how you manage your starter. If you keep your starter at room temp for say
36 hours, you will have a starter rich in bacteria and poor in yeasts, that
will produce a bread that will not be a great riser but will have a lot of
sour flavor. If on the other hand you feed your starter and leave it at
room temp for say 12 hours, your starter will be richer in yeast and poorer
in bacteria, and will produce a bread that rises actively but doesn’t have
much sour flavor.
Given that your bread rose so fast, I would guess that the balance of your
starter tilted toward being relatively stronger in yeasts and weaker in
bacteria. So I would guess that your bread will be relatively mild in
flavor, rather than very sour.
The more tangy starters.
You can make almost any starter more tangy by using a cool rise, but in my
experience the San Francisco Starter, some of the Alaskan Starters and the
Italian starters have the most robust flavor.
My starter from Finland, and the one from London have a lot of tang to them.
The one from Russia, Giza, Yukon, and The Red Sea are the more milder of mine.
Four commercial cultures that produce good tang are available from Sourdough
International for about $15-20 per culture, with instructions and well prepared
and packaged in a way that yields a good culture when activation instructions
are closely followed. The San Francisco is good, I’ve used it as the go to
culture for 10 years. The South Africa wheat culture is a very serious acid
producing culture, in fact one has to carefully watch the fermentation, one
doubling works, you may or may not get 2 doublings before it shuts down.
The 2 New Zealand rye cultures also produce a lot of acid quickly. They work
with white flour as well as rye. Key is dividing the fermentation into 2 steps,
about 1/3 of the dough for the sour fermented 12-24 hours and then the main
dough for 5 hours.