Overfilling bottles a problem?

[pfooti]

I've never particularly paid much attention to bottle fill lines. When I fill my own bottles, I tend to bring things up to about 1/4" from the cap. I recently got some judge sheets back from my first competition, and the one thing that was consistent was remarks that I overfill my bottles. Some investigations into the internet seem to indicate that this might be a reason why it takes me so long to get bottle conditioning done- my pale ales regularly take 3+ weeks to get a good head on them. I thought I was just being frugal with the glass, but apparently I wasn't.

So: is there a real relationship between headspace in the bottle and conditioning? The only strong conclusions I saw were that half-full bottles carb very quickly and completely full (cap on beer) ones take for ever if they carb at all. The in-between stuff has been lacking; I haven't seen any claims about how moving from 1/4" to 1.5" of headspace in the bottles helped or hurt.

I'm going to try this myself; I've got a batch that needs bottling in a few days, I'll make sure I leave more headspace in each bottle. But I'd love to hear from anybody who has dealt with this in the past.

[spiderwrangler]

The most recent issue of BYO has an answer from Mr. Wizard addressing this.

[Quin]

When yeast consume the priming sugar they put off a certain amount (mass) of CO2. That amount of CO2 compresses into the available space and is absorbed by the liquid until equilibrium is reached.

Smaller volume = higher pressure = more stress on the yeast
Higher volume = lower pressure = less stress on the yeast.

Temp also comes into play. The beer can hold more CO2 at lower temps which reduces the pressure in the head space.

Theoretically, if you always filled your bottle to 1/4" from the top, you could reduce the amount of priming sugar and get the same result.

[alan_marks]

By obeservation, when filling a bottle from the bottom of a typical bottling wand, and filling them until the foam touches the lip of the bottle, I find that the area displaced by the bottling wand leaves me the optimum head space and provides what I concider the proper amount space to carbonate for bottle conditioning. That for me is about an inch to inch and a quarter. This also has two benefits for me, I avoid aeration by the beer spashing into the bottle and I can cap on foam to minimize any extra air the beer might take up in the bottle. My head retention is also improved, and I can tell when it is ready to drink by checking out the head retention as I pour a test bottle.

I've been doing quite a bit of testing lately...



Alan

[pfooti]

Yeah, my bigger issue is that it's taking me longer to bottle-condition this beer than expected (or wanted). Two weeks gives me a minimum head and carbing (feels like 1.5 vols), and four weeks gives me the target 2.4 volumes or so. That's a long time. I think it might also be due to my yeast choice- I've been experimenting with Pacman, which does indeed floc like a bomb. Getting enough of it into the bottling bucket might be an issue too. Or it might be my headspace (I tend to remove the wand and then add back that little bit of displacement stuff).

Also, the place where I typically bottle condition (my basement/garage) is in the 55-65 F ambient range, which is a trifle cold. Then again, I'm told Pacman runs down to 40F anyway. Maybe my ten-pound sack of corn sugar was a dud, or my kitchen scale is off. I weigh corn sugar with my less-accurate analog scale which is in the kitchen, my hop-digital scale is in the basement.

Naturally, this calls for experimentation. Better go brew something.

[spiderwrangler]

I generally figure on a month for fully carbed and don't let it bother me... if you are trying to push them sooner, I'd say store them a bit warmer. There should be plenty of yeast for conditioning unless you are really stripping it out. There is a surprising number of yeast in a sample that is just noticeably cloudier than straight water, I know Jamil has talked about it at one point.

[HoozierDaddy]

I find it irritating that judges would even comment on something like bottle fill levels. There are a lot of ways beer might end up in a bottle, and if it's carbonated properly, then fuck off.

[spiderwrangler]

I find the 'cap on foam, cap on foam, cap on foam' to be a bit irritating from the bottle conditioning side. If you are bottle conditioning, capping on foam is next to meaningless.