I pressed about 40 L worth of apple juice 12 days ago. Sweet cider was put into a carboy and foamed heavily after 3 or 4 days for about a week with consitent airlock activity.
In the past two days, the thick foam has gone down to the point where it has disapeared, which I guess is normal in wild fermented cider as it starts secondary fermentation. However, airlock bubbling has stopped, which I'm unsure if it's a normal symptom.
1) Does airlock activity diminish when transitioning from primary to secondary fermentation? Should I expect airlock activity to come back in the next following days?
2) I tried the cider. I think it's a bit low in alcohol content. I previously red that ca. 70 % of alcohol content is provided by primary fermentation. In case my cider ends up a bit short in alcohol, can I add some sugar then or is it better to do it now? Could that be the cause of not having any airlock activity?
I'm a beginner, and I hope this questions are still interesting to some of you that want to attempt a wild fermentation. Please forgive me if all this is too obvious for some of the most experienced brewers here!