San Francisco vs. Poland
We had a little blind taste test here at the southern Fugal base. We compared two baguettes which differed only in the sourdough start used.
The Contestants
Brian Mailman of San Francisco graciously sent me a SF start. I refreshed it twice, baked with it twice, and declared it ready for the taste test.
My start was created earlier this summer from some King Arthur White Whole Wheat flour and water. This start developed very quickly and was made a voluminous loaf after only 36 hours, and it is indistinguishable from my old start, so I think it's likely that they are basically the same culture. Despite the fact that the last time I had used the start was several months before and I started from scratch. So this start is either New Mexican, King Arthurian, or Polish depending on your point of view. (My old start came from a baker in Albuquerque who claims its ancient origin to be Poland)
Methods
When the SF start came I boiled my tools and proceeded to refresh and bake with it. I was careful not to contaminate it with the Polish start.
To prepare these two loaves, I refreshed 25g of each start to 60g, in different vessels and on different counters. Then when they were nice and active I mixed 400g of dough, including salt, until the gluten development was good. It was drier than I like because adding 100g of 100% start would soften it up, but it was all precalculated to give a final hydration of 64%.
I divided the dough into 195 grams each (lost a few grams to the process), then mixed in 50g of the respective starts, again being careful not to cross-contaminate. For some reason the polish dough was a bit wetter, so I ended up adding a tad of flour to it until the consistency felt the same.
I shaped into baguettes and let rise until they were ready to bake. I baked at 450 for 10 minutes then 400 for 5 more minutes, with a little steam (but no cloche) at the beginning.
Results
Both breads tasted good, but neither seemed to taste substantially different from the other. This jives with my earlier observations that the SF start didn't seem to taste any different, although it does smell a little bit different.
Just to be sure we conducted a blind taste test. My wife said the SF one tasted ever so slightly more sour, but that they tasted mostly the same. I said that the Polish one had a more complex almost-sour undertone, but basically the same. Neither one was noticeably sour, which I'm sure had to do with the technique as both of these starts have produced mildly sour bread before with the same ingredients.
The most significant difference was in looks, as you can see at Flickr. Look at the crust comparison but don't jump to conclusions - the difference is easily explained by the position in the oven and my shaping (mis)technique. Look at the crumb comparison, though. There was more rise and spring in the Polish baguette, and the resulting crumb is more desirable. However I can't completely discount the possibility that it remained slightly more wet than the SF dough, which could account for it. Or perhaps it was temperature-induced, or the SF start finished rising sooner and was slightly overproofed. There's just not enough data to tell, really.
One thing is clear, there is no major difference in the two baguettes, although there is a very slight difference in taste. Far more important to love the start you're with than to chase after that perfect start. Nevertheless, for your benefit I've asked for a sample of ACME start, and will get a sample of the authentic Polish start from my dad and will repeat the experiment and see if either of those tastes significantly different from my old standby.