Hello 8 days ago we pressed our 1st batch of cider produceing 100 litres in 4 separate 25lt fermenting bins. we wanted to take the organic route so no tablets or yeast was added, All seemed to start well, after 4 days froth formed on top, but no bubbles in the bubbler . Then for some reason (maybe temprature to low) froth disappeared and then re-appeared 1 day later. It has been following this pattern since, but still with no bubbles in the bubbler, in 1 of the bins the smell started to become a little vinagery but then changed to a sweet smell as the froth re-appeared, this is the only bin i have opened to investigate. Can anyone help with advice or am i just being a little to impatient? Afterall slow fermenting is supposed to make better cider?