Bottle shapes impact on carbonation?!?!?

Hi All,

I have a batch of porter that I bottled in two separate bottle types. Most went into Sierra Nevada type bottles, while one six pack went into Fullers Londer Porter bottles. Now the strange part.... all of the SN bottles carb'd up fine with no issues (in about 3 weeks). Not one of the Fullers bottles has carb'd (6 weeks plus). I'm not saying zero carb, but pretty close. No head and no real fizz.

Has anyone seen different bottle shapes (but same bottle size) having that much of an impact on carbonation?

I think it has more to do with the head space than the bottle type. Maybe the way you fill them is having an impact. Less air volume vs more, something like that

I actually used the Coopers drops on this batch as well. Also used bottling wand and filled all the way to the top so that the only space in the bottle is what was evacuated by the wand itself.

are you sure the tops sealed well. Most imports have a slightly different size crown, so the don't seal up as well with a wing capper

JeepDiver said:

are you sure the tops sealed well. Most imports have a slightly different size crown, so the don't seal up as well with a wing capper

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I'm guessing this is the issue. Bench cappers work better on more types of bottles.

I did use a wing capper so that is a possibility. Seals seemed fine, but i'm guessing it would be hard to know for sure. Anyway to test????

union, not saying a process issue is impossible, but I doubt it. I've bottled about 20 cases of beer and this is the only six i've had issues with. Just strange because it wasn't a couple random bottles, but six specific bottles.

way to test:

put suspect empty bottle in freezer

cap it

set it out and let it warm up and sit for a few days

open it... if you don't hear a good "fssssst" when you pop it, it wasn't sealed.

It might be dependent on bottle shape. Volume displacement varies depending on the height of the bottle. A shorter, fatter bottle will have less head space when the bottling wand is removed than a taller, narrower bottle because less of the height of the wand is in the beer. This amounts to a change of head space and of volume of beer in the bottle. The change is in proportion to the relative heights of the bottles. A 6" bottle will have 2/3rds the head space as a 9" bottle.

unionrdr said:

That's not a good test. Why? Thermodynamics. Things change state at different temps. In other words,the caps will be loosened slightly by expansion /contraction between putting them in extreme cold & warming again. Let'em carb up,then place under water in a bucket or something. If the seal is bad,you should see bubbles just like a leaky inner tube.

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Not enough to make a difference. Look, the cold air from the freezer will be more dense than room temp air. You cap the bottle when it's full of cold air, let the air inside warm up for a few hours by sitting it on the counter or on the porch, and then later when you open it should be partly pressurized. Hence, the "pfffft" sound. If you're worried about the thermodynamics of the whole thing, then use a warm cap on a cold bottle. No big deal.

If the cap is loose enough to be significantly displaced by the temperature difference of moving from the freezer (-20C) to room temp (25C), then that cap was too loose to start with.

The advantage of the previously suggested test is 1) it doesn't require potentially wasting beer and 2) it doesn't take weeks and weeks. Furthermore, your stated test might not detect a slow leak, if the tester is impatient. I would suggest empty bottle tests as a first course of action.

ChuckO said:

It might be dependent on bottle shape. Volume displacement varies depending on the height of the bottle. A shorter, fatter bottle will have less head space when the bottling wand is removed than a taller, narrower bottle because less of the height of the wand is in the beer. This amounts to a change of head space and of volume of beer in the bottle. The change is in proportion to the relative heights of the bottles. A 6" bottle will have 2/3rds the head space as a 9" bottle.

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Excellent point! I'd never heard of this before. You learn something new every day!

ChuckO said:

It might be dependent on bottle shape. Volume displacement varies depending on the height of the bottle. A shorter, fatter bottle will have less head space when the bottling wand is removed than a taller, narrower bottle because less of the height of the wand is in the beer. This amounts to a change of head space and of volume of beer in the bottle. The change is in proportion to the relative heights of the bottles. A 6" bottle will have 2/3rds the head space as a 9" bottle.

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wrong again. The wands volume displacement is the same regardless of the bottle height. I use both & see it a lot. the bottle can't change the volumetric area of the wand itself. And the freezer cools it down way faster than the fridge,so expansion/contraction rates would be greater. Enough to make a bad situation a lil worse. They're not leaking because of the bottles. The ones that would leak won't take the size caps we have by a little bit.

The wands volume displacement is the same regardless of the bottle height

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In a taller bottle more of the wand would be submerged in the beer and so more of it would be displaced. A 9" bottle would have 3 more inches of the bottling wand submerged than a shorter, wider, 6" bottle. Filled to the top, the taller bottle would end up with a higher volume of air space when the wand was removed.

MichaelBrock said:

In a taller bottle more of the wand would be submerged in the beer and so more of it would be displaced. A 9" bottle would have 3 more inches of the bottling wand submerged than a shorter, wider, 6" bottle. Filled to the top, the taller bottle would end up with a higher volume of air space when the wand was removed.

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Thanks, I knew that I was correct, but you explained it better.

while the increase in bottle wand displacement is absolutely true.... that's not why they are flat.... the difference we are talking about with the displacement issue is fairly small and does not account for the difference between a perfectly carbed beer and a totally flat one.... Perhaps a perfectly carbed one and a sllightly under carbed... noticeable only by the brewer (him/her)self. I'm still inclined to say, those bottles are leaking (hint hint, i've had this problem also... it's amazing how many different size bottle mouths there are out there )

By no means an expert, but if wondering if your getting a seal on one type of bottle over another you could also try an instant, and possible messy test. Fille one of the bottles in question with some sort of non alcholic carbed liquid, Warm diet cola would work nicely. Apply cap as you would when bottling, head outside and have somone who trusts you ( or did till today) shake the bottle while pointing away from people. If it is an equipment issue getting a seal you will know verry shortly.