Flat Belgian quad

Hello, homebrewers! Was hoping to pose a question and get some insight. New member here, so apologize if this had already been covered.

I recently finished bottling a Belgian quad (on 9/4) which came in around 9.7% abv (OG: 1.090, FG: 1.016). Even though I know it has much longer to age, I tried a bottle after 2 weeks, and was completely flat. It occurred to me that my priming sugar amount may not have been ideal, (I used 2/3 cups corn sugar in 16 oz. water) especially for a higher gravity beer. I suppose I should mention the yeast I used was one packet of liquid Wyeast 3787 Trappist yeast.
Will that amount of priming sugar/yeast likely be sufficient for carbonation eventually, given enough time spent aging? I assume the yeast went dormant given the longer fermentation time (4 weeks primary, 14 weeks secondary). My fermentation temp is adequate I believe, as the room it sits in stays between 70-72°F.

If not, is there a solution anyone could offer? I’ve read here and there online about people re-pitching small amounts of yeast by uncapping, sprinkling a few grains in each bottle and recapping.
So far, I’ve tried to gently agitate the bottles, i.e., one inversion daily for the past 5 or 6 days. Opened another tonight and it was just as flat, so it’s been around 3.5 weeks.

Any advice would be greatly appreciated. I put a lot of TLC into this beer and I dont want one miscalculation on my part to undo all that work and patience :wink: Thanks!

It has been my experience that one would allways pitch additional yeast after 4-5 total weeks of fermentation, primary and secondary.  If you’re saying your combined primary and secondary were 18 weeks, than yes, you need additional yeast for bottle conditioning.  How to go about accomplishing that at this stage is beyond me.

Further, regarding the priming sugar, 2/3 of a cup may have been plenty depending on the volume of beer you were priming.  I prime using weight, not volume.  So to prime 4.8 gallons of beer to a C02 level of 4.2 volumes you would need 4.07 [+/-] oz. of corn sugar regardless of the FG.

Yes, I definitely have to get in the habit of using weight and not volume. Especially with corn sugar, as I would guess it has inaccurate weight by volume due to how “fluffy” and full of air it is.
You’re correct that it was a 5 gallon batch, and no I didnt repitch prior to bottling (as I should have).

I’d like to avoid uncapping, pouring them all into a bottling bucket, pitching additional yeast, rebottling and recapping if I can. Not only due to the labor-intensity of it, but also because of the increased risk of unnecessary oxidation and contamination. Hopefully another course of action can save this beer.

Also, if pitching additional yeast into a beer like this, what sort of yeast is recommended? Like a CBC-1 cask conditioning yeast or a regular US-05? Preferably something more flavor-neutral I would think?

Did you originally make a yeast starter for the 3787?

No, just smacked the package and pitched a few hours later

Ah, OK, that’s likely it…your yeast had had it.  You should be making a starter for any beer over 1.040, IMO, and especially for a quad.  I’d guess at this point you don’t have enough viable yeast left to carb the beer.  If you wait, it very well might carb eventually, though.

Ah, I see. That’s what I was afraid of. I’ll remember that advice for next time.
Anything I can do for it now? Sprinkle a few grains of a dry yeast into each bottle and recap? Any yeast youd recommend?

You could sprinkle a few grains of just about any dry yeast into each bottle.  IMO, that’s a PITA.  What I’d try first is shaking them up and putting them in a warm place.  Wait a few weeks and see what happens.  I think there’s a fair chance they’ll carb given enough time.  There’s likely at least some healthy yeast in there and you need to give it time.

Ok thanks a lot for the advice. I suppose I’ll just have to keep being patient :wink:
As a side note, it feels very unnatural and almost counter-intuitive to pick up a bottle of beer and shake it lol

In that same vein, does having a yeast starter typically eliminate the need for pitching additional yeast at bottling time?

In my experience, the only times I’ve had to pitch yeast for bottling were when I had a 12% beer that had been aging for months.