Fermentation seemed to stall and restart

[AnotherKiwiBrewer]

Can anyone explain what's going on here - see attachment. Fermentation started fairly normally but seemed to stall then restart.... I didn't do or change anything from the start of fermentation till now.

 

[RPh_Guy]

TILT hydrometers (or similar) are not very accurate.

 

[AnotherKiwiBrewer]

TILT hydrometers (or similar) are not very accurate.

Granted, but even if the absolute accuracy is off, it was still logging minor changes during the stalled period, then the sudden restart.
What I'm interested in is if people know of fermentation characteristics that could explain a stall and spontaneous restart?

I've never seen this pattern before in over 40 brews with the Tilt - it has stalled once or twice but i've had to do stuff to restart it.

 

[RPh_Guy]

Probably fermentation wasn't actually stalled; there was some combination of kräusen, hop debris, break material, and/or bubbles falsely elevating the reading for a period of time.

 

[dmtaylor]

I rock my fermenter frequently to knock some of the yeast & hop schmutz off the Tilt, then it reads accurately. Each time I shake the fermenter, SG usually changes by 1-2 gravity points. Here's what a timeline looks like for one of my ferms:

 

[AnotherKiwiBrewer]

I rock my fermenter frequently to knock some of the yeast & hop schmutz off the Tilt, then it reads accurately.

Probably fermentation wasn't actually stalled; there was some combination of kräusen, hop debris, break material, and/or bubbles falsely elevating the reading for a period of time.

Hmm, you both make good points - maybe I've just been lucky to date. I'll give it the 'ol shakeup tonight and see what happens!