My first lager (a German Pils) turned out quite good! From the keg, it's great, but the half dozen bottles I filled are completely flat!?
I used a little more priming sugar per bottle than my usual amount for ales (which carbonate up well in around 10-14 days at room temp.)
I'm wondering, has the 3 weeks lagering flocculated so much yeast that there is not enough to get the priming sugar going?
And if so, how does one compensate for this?
Usually its fine. There's plenty of yeast around for carbonate, but it will take longer. You should still be bottle conditioning at 60-70F to get the carbonation to happen.
If you lager a beer for a real long time, say months, a dose of yeast may help. One way to do this is to just rack some of the settled yeast along for the ride as you transfer the beer.
I have also had good luck using a third of a packet of dried yeast. I rehydrate in half a cup of boiled/cooled water first. Add it along when racking to a bottling bucket. I did this once with a Baltic Porter I lagered for 6 months and it came out nicely carbonated.
It's possible much of the yeast dropped out and thier wasn't enough in suspension.
Generally if you bottle condition you accept there will be a yeasty ounce of beer in the bottle.
That being said to help make sure your Lager bottles get a dose of yeast some of the secondary yeast should be transfered to the bottling bucket or stirred up when adding the priming sugar. Then your bottles are your fining stage.
Alternate solutions
The beer should carbonate fine.
I've personally had pilseners lager for four months and had no problems with carbonation. It usually takes a a few more weeks than ales, my four month lager took almost 6 weeks before it was properly carbonated. My friend lagered a doppelbock for 6 months, bottled it without adding any yeast, left the bottles for a few months and it carbonated just fine.
I recommend that you give it some time and, as @brewchez said, keep the bottles at 60-70 F (15-21 C).
