Head Space & Bottling

Greetings All - I bottle my brews; have not quite made it to the kegging area of this craft.  So my question is: how much is the finished carbonation of a beer affected by head space in the bottle?

I bottled a Tripel last summer that we're enjoying now and the carbonation seems a little light.  It was bottled on 750mL champagne bottles to avoid any possible bottle bombs.  While filling the bottles, I stopped roughly 3" from the top (I could have filled another inch) and I'm wondering if that could have some bearing.  My target was 2.4 volumes.

The carbonation of all my other brews have always turned out perfect.  This brew, however, seems light for a Tripel.

I just brewed a Tripel last weekend.  In my research on the style, the carbonation is more appropriate at around 3 volumes of CO2 or maybe a little higher.  This lightens the perceived body of the beer, making it lighter on the tongue.

In terms of the head space left in the bottle, I've only occasionally left more than an inch of head space when bottling and found it to be lacking somewhat in carbonation of the beer.  I'll caution that by warning that those were usually the first bottles I tried for a carbonation test, so they may not have been fully carbonated to begin with.

Greetings Oginme - thanks for your response.  So if I understand, you're suggesting my target of 2.4 volumes was low to begin with?  You're probably right. However, my question remains unanswered. Can the head space affect the carbonation?

Okay, I did some research and found an article in BYO from January, 1997 titled:  "Master The Action: Carbonation", by Rob Louriston.  Long story short, yes, headspace makes a difference.

...."For a given amount of priming sugar, the greater the headspace, the lower the carbonation."

As this article explains, headspace is measured in volumes and the CO2 will reside in this space as opposed to mixing in the beer.  So the larger the space, the greater amount if priming sugar is needed to fill the headspace and still hit the target CO2 volumes.

So I agree with you, Oginme, my target of 2.4 volumes was, in fact, too low, thank you.  And my carbonation issue was compounded by the fact that I didn't fill the bottles as much as I normally would have.

I was thinking about this issue last night.  Your loading of sugar will produce a finite amount of CO2.  With a larger head space and because gases are more compressible than liquids, there is a less pressure forcing the additional CO2 into the liquid (beer).