Jumping on the Ischia bandwagon here.
I'm in the process of activating my first Ischia starter, and want to make sure things are ok. I had to leave town for a day and a half in the middle of activation, which seems to have dealt the starter a setback.
In the beginning, I was paranoid about contamination, so I sterilized my first batch of flour (KAap) in a canning jar in a pressure cooker, and hydrated with water that had been boiled. I then let it sit at exactly 90°F.
After 18 hours, it was bubbling madly—seemed more like the LAB than any yeast. The liquid on top was clear, and it smelled strongly of fermentation (my girlfriend said it smelled like kefir).
I then dropped to 70°F and started feeding every 12 hours. It bubbled, but never foamed up. Smell eventually got milder over 48 hours.
Then I had to abandon it for about 30 hours. I gave it a feeding beforehand and left it at around 65–75°F. When I got back it had a lot of clear liquid on top, a fair number of bubbles, and a sweeter fermented smell. I poured off about 2/3, fed again, continued at 70°
Now after 12 hours the activity seems very low. Clear liquid, smells good, but very few bubbles. Should I feed as normal this morning, or do something else?
Thanks so much for any input.
Edited to add: I checked the pH and it's hovering around 3.5. Is this unusually acidic? Could this be impeding the yeast? And if so, is there a way to buffer it besides feeding it a lot?
Edited 5 hours later to add: I dumped all but a cup and fed it, and it seems to have sprung to life. This time I divided into two batches, just as an experiment: one is in a cooler at 70°F, the other is on the counter at 80°F. Both are doing well. The cooler one last measured pH 4.2 and smells sweeter. The warmer one measured pH 3.9. This fits what I'd expect. I'm assuming the yeast will ultimately build up stronger in the cooler one, since 70-75 seems to have the highest yeast vs. LAB activity.