The idea for this test came from a thread by KipperCat asking about how to make a less sour sourdough. There was a general consensus in the thread that starter maintenance routines (feeding ratios and hydration) would have a small effect on the sour aspect of sourdough while varying the rise and proofing times would have a much more pronounced effect. Bill suggested an experiment, and as I was planning on baking a couple of loaves, I gave it a shot.
I began the process by pulling Leon, my 100% hydration starter from the fridge on Wednesday and feeding it as I usually do -- 1:4:4 (in this particular case, one ounce starter, four ounces of water, four ounces of KA AP flour), once a day. This starter is very active, and after the Thursday AM feeding he was easily doubling within about 3 hours...I stir him down a couple of times during the day and he just rises right back up, so he seems content.
On Friday morning I set out to create two two-pound sourdough loaves, staying close to the basic sourdough recipe in The BBA using my starter as the base instead of his barm.
The only real pet-peeve I have with the BBA is that all of his measurements are in ounces. Why? It isn't that hard to provide both ounces and grams, and you can be more accurate with the grams...He has measurements like ".22 ounces" in there -- who has a scale that is accurate to a hundredth of an ounce?! ...so anyway, As I build his recipes, I convert the measurements to grams so that when I come back the second time I'm not still frustrated. All of this is to say that from here on out most of my measurements will be in grams.
I fed 100 grams of my starter with about ~60 grams of water and 200 grams of flour, leaving me with a freshly fed starter that should have the same hydration level (~70%) as Reinhart's firm starter, scaled up a bit to be able to make a total of four pounds of bread. As directed, I covered the starter and left it on the counter to feast for a few hours.
After 3 hours the starter had easily doubled in size, so I moved it to the fridge until Saturday AM.
Saturday morning I pulled the starter from the fridge, allowed it to come to room temperature and started building the final dough. My mixer doesn't handle 4 pounds of dough well, so I divided the starter exactly in half, and then went through the build process twice, adding exactly the same amount of flour, salt and water, by weight, to each batch -- since I was striving for identical loaves over perfect loaves, I measured all the water going into the first loaf, then added exactly that much to the second loaf, regardless of consistency. Fortunately, since everything else about the process was identical, the water amount was just about right both times, too. I also mixed, kneaded, rested, and kneaded each batch for the same amount of time, trying to ensure that everything about these two loaves was identical thus far. The one difference I did allow here is that I used warm water (as directed by the BBA) for the "fast" loaf and I used cooler water for the "slow" loaf. At the end of kneading, the fast loaf registered at 82 degrees, the slow loaf about 5 degrees less.
The fast loaf was placed in an oiled bowl and left on the kitchen table to rise, with the ambient temperature varying around 75 degrees. The slow loaf was placed on top of a glass bowl sitting in a cooler above a layer of ice, with the temperature staying somewhere around 50 degrees.
Three hours later, the fast loaf had doubled, so I shaped it and returned it to its "warm" environs. As hoped, the fast loaf wasn't showing much progress at all.
Another two hours passed, and the fast loaf was ready to go. I fired up the oven, butchered the scoring, and baked.
By 4 PM (7.5 hours of rise time), the slow loaf had about doubled, so I pulled it out, shaped it, moved it back to the cooler and then headed out to dinner. Six hours later, it was time to cook. I pulled the dough from the cooler and fired up the oven again. About a half and hour later, the second loaf hit the fire.
Two identically handled loaves, one with a total of 5 hours of bench time, one with a bit more than 13 hours.
1) Both loaves are still far to dense. I am pretty sure my starter is just fine, so I'll be upping the hydration of the final dough the next time around.
2) It was a foolish mistake to take the slow loaf from the cooler and have it in the oven a 1/2 hour later, but I didn't want to be up all night, so I rushed it. The overall results would have been better had I left the loaf come up to room temperature over an extra hour or so instead of putting the cold dough into the oven...
3) ...finally, the flavor result. After tasting each loaf I can conclusively say that there is virtually no difference in flavor between the two - both are only ever-so-faintly sour, which is not what I'm going for. So I'm surprised - the extra time for the rise and the proof didn't affect the flavor.
So what next? Two things:
1) I'm sure that what Bill and Brotkunst are saying is on the mark, so I'm undaunted. I will try this experiment again (but not next weekend - family is in town so I don't have as much time to fiddle)
2) I suspect there may be all sorts of ways that the density and the flavor are intertwined - perceptually, from a surface-area standpoint, what the density says about the flour and the yeast and timing...all that stuff. So for the short-term I'm going to focus on getting a single loaf of sourdough to come out well, then I'll get back to worrying about the flavors...