strange bottle carbonation issues

[brewuuhu]

I bottled a Munich Helles that I made with Wyeast 2565 (Kölsch) about 7-8 weeks ago. I primed the bottles with ~77g dextrose for the full 11 liter (~3 gallons), which is on the high side if anything.
Since 2565 is such a powdery strain, I put the carboy on the balcony for 2 nights to cold crash after fermentation was done, but I found it it was -1 degree celsius outside the second night (30 freedom degrees).

Now the problem is that the first 2 bottles I opened after a week or 2 were great, with a nice head and properly carbonated. Only a tad sweet, but I think I mashed too high. After that however, the next 5-6 bottles I tried were all dead. No foam, no or barely any carbonation. There was a tiny 'pssht' when I opened the bottles, so I'm pretty sure the bottles were properly capped.

Any possibility that I killed all or part of the yeast during the night on the balcony? Seems very unlikely too me. It's especially weird since the first two bottles were great, but it could be the last bottles of the batch with more yeast or so. Is 2565 just a slow yeast and should I wait longer before popping open another one? Thanks!

 

[LLBeanJ]

I'd give it more time. A week to carb usually isn't long enough, three weeks is more like it. Make sure the bottles are at a good temp for carbing, say around 70-75 freedom degrees.

Also, I'm going to "like" your post because you used the term "freedom degrees."

 

[brewuuhu]

I'd give it more time. A week to carb usually isn't long enough, three weeks is more like it. Make sure the bottles are at a good temp for carbing, say around 70-75 freedom degrees.

Also, I'm going to "like" your post because you used the term "freedom degrees."

haha cheers!

Beers were bottled around 7 weeks ago already though. I'll give it more time but never seen beer needing this much time to carb. They've been at room temp too.