Added yeast to my keg to get it to carbonate?

[Dovage]

So I brewed a Belgian Dubbel. Everything went great on brew day. Put 5.5 gallons of wort at 1.076. Pitched Wyeast 1214 Belgian Abbey Style yeast. After 3 weeks I had a stable gravity of 1.015. Beer tasted awesome. I wanted to keg condition for another month or so, so I added 3.5 Oz of table sugar to my kegged beer. I've done this in bottles before and there was enough yeast still in suspension to carbonate, even at high gravity. Just tapped my keg after the month, completely flat and sweet. Yeast must have been nackerd. So I just pitched 2 Grams of US 05 and sealed it back up.
Thoughts? Anyone do this before and want to share there experience?
I really don't want to lose this beer.

 

[VikeMan]

Assuming you didn't forget to add the table sugar, the US-05 should take care of it. It has an alcohol torerance of about 11%, so it should be able to carbonate your ~8 ABV beer.

Also, are you sure your keg was well sealed? Many are marginal and won't seal properly without the lid being initially seated under pressure. If this was the case, your carbonation could have been made and escaped.

 

[Dovage]

Thank you, that is reassuring. I thought about the lid not being seated but only after the fact. Should have set it with C02. Did so after adding the yeast.

 

[Biggz1313]

Also, are you sure your keg was well sealed? Many are marginal and won't seal properly without the lid being initially seated under pressure. If this was the case, your carbonation could have been made and escaped.

I would bet $50 this is what happened. Next time, add your sugar, then hit the keg with like 8 or 9 PSI to seat the lid and you'll be good to go.

 

[VikeMan]

I would bet $50 this is what happened. Next time, add your sugar, then hit the keg with like 8 or 9 PSI to seat the lid and you'll be good to go.

I would apply a couple of PSI and leave the gas on for a day or two. With one shot at 8 or 9 PSI, over 90% of that headspace CO2 is going to dissolve into the beer, leaving not much pressure to maintain the seal if there's much lag time for the yeast.