Bill,
I'm new to the forum and greatly appreciate your insight and all your contributions.
I am having trouble with my Ischia in that it seems to be on the acidic/sour side. I noted from reading your posts that time and temp are keys to controlling acidity. Could you possibly expand on this? The pizzas I've made lately seem to have some sourness to the crust. I believe some sourness is normal, but in reading the posts it seems Ischia is the preferred starter, if so, I would suspect that I am experiencing more sourness than what the norm seems to be. I also read in Marco's posts about ph levels being in the 4.1-4.4 range. is this something you actually measure? if so how and what effect does this have on the sourness?
I like a little sourness in my pizza crust, but not too much. The slight charring of the crust that comes with baking at high temps can also add some tanginess, although it is a completely different flavor profile than the acids from starter metabolism. My goal is to try to balance those flavors for maximum effect.
The theory is that the higher fermentation temps are optimal for the critters that produce acids. I try for a fermentation/proofing temperature that is high enough for the yeast to produce the gasses that create the bubbles in the dough that will give it the desired texture but that isn't high enough for the production of too much acid. For my particular conditions, 65F-70F seems to work best. At this temp, my dough needs 1-2 days to ferment/proof depending on the amount of starter I use. In some of my breads when I want a stronger hit of sourness, I use 75F-80F.
I do have a pH meter that I use for making cheese, but have not recently used it to measure starter pH. Perhaps something I'll do if I get a chance.
Bill/SFNM