Beer Forum

Lately I've been noticing a fair bit of variability in my bottle conditioning. Some beers will go way over-carbonated, some not. I would love help thinking through the sources of variability here, in case I'm missing something critical.

I routinely check the gravity of my beer as it is fermenting, and usually let it sit for 1-2 weeks after it stops dropping in gravity. I never bottle anything that's above 1.018, unless it started pretty high to begin with.

Using the nomograph from Palmer's book, I should be dosing my beer typically with 0.7 - 0.8 oz/gal of corn sugar to hit 2.25 volumes. I usually stick with about 0.6 oz/gal (3 oz in 5 gal).

I bottle in clean 22oz glass bottles, let the beer sit at 63F for a few weeks (usually 3 weeks or so), and then when everything seems good I put the batch in my refrigerator (converted chest freezer, actually) and hold it at 33F indefinitely. Sometimes I'll have too much beer and move stuff out of the fridge back into the warmer 63F basement. I am pretty fastidious about sanitization, I use a lot of star-san in the obvious places.

There are definitely beers that come out of this process (not all of them, and as far as I can tell it's not even every beer in the batch) where after a few months, they're crazy. Pop the top and expect a lot of foamsplosions. I thought at first that maybe I was having a sanitization problem with gusher infections, but I have since read that (A) gushers make the remaining beer taste bad and (B) they're likely to be a whole-batch problem stemming from infection in the lines or bottling setup.

I'm wondering if maybe I'm not getting an even distribution of sugar in the priming bucket? I pour the sugarwater into the bucket, then rack the beer into it. I don't stir, as I try to omit anything that would add a risk of infection.

My inclination is that this probably happens more often with my WL002 beers, the stouts and browns I brew. At first I thought it was something about residual long-fermenting sugars in dark malts that the yeast were nomming on over time, but maybe it's the yeast? I have a similar problem with WL380, a hefeweizen. Starts out fantastic, but then after two extra months in the bottle, half of them are waaaay overcarbonated.

Maybe the yeast is floccing out too soon, and the disturbance from transferring to the bottling bucket reawakens it? Unless my math is off, 2oz of sugar amounts to about one gravity point in 5 gallons (44 ppg for corn sugar, 16 oz per pound, 5 gallons), so if the yeast even have one more point of fermentation left in them when they go to sleep, that'd throw off the priming calculations something fierce.

Ideas? Direction? Maybe I should bite the bullet and force-carbonate instead. At least then I could use a plate filter or something to get the yeast out of there.

Are you repitching harvested yeast? I used to get gushers using poorly handled older yeast slurries.

Otherwise it reads like your bottling procedure is sound.

One general thing-

63F is pretty cool for bottle conditioning. Try putting them somewhere where the temp is 70F.
(Make sure they are not sitting on a concrete floor, which will suck the heat right out of them).

Most of the time, vastly different carbonation levels is because the priming sugar is not mixed in uniformly enough. Usually, putting the priming sugar into the bucket and then racking on top of that is enough to mix it in evenly. Make sure you have enough "flow" coming into the bottling bucket so that it does make a slow swirl by itself.

Otherwise, everything else sounds right to me.

HTH-

BDawg wrote:Most of the time, vastly different carbonation levels is because the priming sugar is not mixed in uniformly enough.

This has to be it. I used to have the same problem... batch after batch some were flat and some had huge heads. When this resolution was pointed out to me, it seemed rather obvious. For the last few years I just take my stainless paddle (after sitting in EZ clean water or whatever you use) and give the beer a quick stir in my bottling bucket. I suppose this exposes the beer to a little more oxygen and possible contamination. As far as oxidization, I haven't noticed. And as long as your sanitizing practices are good, I wouldn't get too caught up worrying about this method contaminating anything.

Not exactly sure where I heard this, but it is best to SLOWLY mix by moving your spoon back and forth and not to swirl. Stirring in a circle, especially quickly, will create a vortex like a stirplate and bring in more oxygen.

Since doing that, I've had completely consistent carbonation.

Stir it with your racking cane as you transfer.

I start the siphon w/ about a gallon in the bucket - then slowly (30 seconds or so) pour my sugar water combination down the side. I also make sure that my siphon hose is angled so the beer rotates/spins as it goes into the bucket - I've always assumed that's what helped mix the sugar evenly throughout and I've never had any problems.

Like everyone else mentioned try actually gently stirring to make sure the sugar is evenly and completely distributed, If that doesnt fix the problem then it is somewhere in your conditioning/sanitation regime. It could be that they are not completely carbonating in the time temp given and thats why when you bring them out of the fridge some of them continue to ferment, Condition warmer like mentioned and that should help speed the yeast up and let them finish.