After racking no fementation from top off juice?

The other day I racked to a tertiary carboy, 6.5 gallons of cider. The cider had been sitting on 1/2 inch of lees for over a month and a half and had become completely clear.

I ended up needing to top off using about 1/2 gallon of juice because I accidently stirred up a bunch of sediment and had to stop siphoning.

It has now been 4 days since I topped off and there has been no airlock activity at all. Shouldn't that much top off juice kick start a little activity?

Take a rally close look at your carboy, are there little air bubbles running up the side where the bottle constricts up to the opening. They are small and infrequent, but they should be there. That much juice in a tertiary would ferment out over time, but it may not build up enough pressure to make the air lock bubble as in primary fermentation.

No little bubbles yet. I did have them before I racked, but none so far and this is day 5 since I racked.

I made a raspberry braggot last winter and after I moved it to the tertiary I topped off with some honey water and four almost 3 months those little tiny bubbles kept running up the side. I was wondering if it was going to every stop. Another year and it should be ready.

I had something similar happen to me, but when I took a quick OG reading it was obvious that it was fermenting just not that visible, so it might be a good idea to take a quick reading.