"If you start me up...

[Taff]

I'll never stop."

.. to quote Mr Jagger.

I had two demijohns of Apple wine/cider on the go. After about a week they stopped, from what had been a fairly vigorous, bubbling.

I left them for a week, with no bubble.

Go everything ready to start transferring to another couple of demijohns to let clear, and the buggers started bubbling again.

Why?!?!?

 

[jof]

My cider is still bubbling away a month into fermentation. It's in a utility alcove off the kitchen - so it's probably at 19c.

If you are using real corks on your demijohns, it's possible they have dried out & the CO2 is just leaking out through it rather than going via the air lock.
Also were they in a shed & restarted when you bought them into say a warm kitchen to do your racking off?

 

[Taff]

Cheers butty! They were still in the warm kitchen, and still had the bubblers in. I'll leave them in place and see how long the, now sporadic, bubbles occur for.