I have a couple questions about back sweetening a mead that has already been bottled and aging for a year and a half. I have tried 3 bottles at different times in the aging process with the most recent tasting at the 1.5 year mark. Every time I try the mead it gets a little better but I feel it needs to be slightly sweeter for my taste and I wanted to try and carbonate some. My first question is: I have a kegging system for my home beer and was thinking about taking 5 or so of my already bottled mead (approx. 1 gallon) and dumping them into a keg to carbonate as well as back sweeten. I never used any yeast killing chemicals to begin with before bottling and have not had any problems with bottle bombs (I'm assuming the yeast hit their tolerance during fermentation). I was wondering if I can just back sweeten with a 50/50 mix of honey and water directly into the keg with the mead and then carbonate as I would beer? And secondly, what would be the proper amount of honey to start with to add to a 1 gallon batch? Any help would be appreciated!