Backsweeten after kegging and carbing??

I kegged up my first cider last week and took a taste yesterday. I'd like to get a bit more sweetness in it and was considering backsweetening with concentrate. Is this something I can do after it has been carbed or did I miss my window? Thanks.

 

You can still sweeten. You will lose a lot of the carb to open and mix the concentrate, but just hook it back up and your in business.

 

Easy enough, thanks!

 

I've done lab work measuring how much carbonation is lost opening and re-closing cider. Surprisingly little carbonation (i.e. not enough to register on the equipment) is lost if you close up within a minute or two.

Helps to chill it down before opening.