Apple - Pause screen recording in QuickTime X

1. record as usual
2. when ready to pause, move your mouse over to the recording box and click anywhere to activate that box (the Quicktime Program)
3. press "option button" on keyboard and the record bar will change to Pause ||
4. BUT, this DOES NOT PAUSE the timer, to do that,click the Pause ||
5. Now, it's truly PAUSED and you can let go of the "option" button
6. Now, the record button turns RED, when in this mode, it's PAUSED
7. To restart recording, simply click the RED button
8. Do steps 2 to 7 all over again for another pause in your recording

There are two options you can exercise, and they both involve post processing.

You could either stop the recording in lieu of a pause, and start a new one, then splice them together in post; or, keep recording, and manually trim/cut out the middle aspects you wished to pause through.

If audio accompanies these recordings, I suggest using an audible cue that you've reached a pausing point. Anything sharp such as a clap is a great marker to remind you down the road where exactly to trim the fat.

there is vwery good answer here worked for me on Sierra.

The key steps: Click on Quicktime in the dock to make it active press Esc to bring up the Recording bar hold down Alt (option) to reveal the Pause button click on the Pause button click on the red button to resume recording