Kegging a beer with added sugar?

I'm looking to get into kegging because bottling can be such a hassle. I noticed there is no need to kill the yeast, because it's work is mostly done. There is also no need to add priming sugar because you're carbonating by pressurizing the keg with CO2. What would you do if you wanted to add something with sugar before bottling? For example, if you wanted a beer with a very fruity flavor, you could make a fruit syrup. If you were bottling you wouldn't add priming sugar since the syrup would reactivate the yeast.

What can you do when kegging? Do you kill the yeast? Or carbonate at much lower PSI?

 

You have 3 options

1) Add the syrup and let the keg sit at room temp. That will naturally carbonate the keg like it would a bottle.

2) Add the syrup and keep the keg at serving temps. The yeast won't be active at those temps and you can carbonate like you would any other keg. That will keep some of the sweetness though, which may or may not be a good thing depending on the style. You need to keep the keg cold until you drink it all.

3) Kill the yeast.

 

You could add something to neutralize the yeast.

Of you could add the fruit syrup, and immediately chill the keg and begin carbonating before the yeast has a chance to ferment anything. As long as the keg stay cold, the yeast will stay dormant and won't ferment the sugars in the fruit syrup you added.

 

If the keg is being carbonated in a fridge than there is no need to make any changes. The year will not be working too hard (or much at all) at those temps. But that will mean that none of the sugar will ferment out, so the finished beer will be sweeter.

 

A few extra notes on those items:
2 - depending on the yeast and the temperature you are storing the keg at, you may still get some yeast activity, it would be at a much slower rate than normal though.

3 - probably your best option if you are wanting to keep the sweetness from the added sugars. Add campden tablets to kill the existing yeast and then add your fruit syrup and then carbonate.

 

Awesome guys, thanks. Good to know all the possibilities.