SQUEEZE YOUR BOTTLES?

[trucker5774]

We take great care not to introduce oxygen into our beer and take care to keep a blanket of CO2 over it. I tend to use PET bottles........Is there any benefit to squeezing them so that the beer fills the head space and then screw the cap on. Would this exclude all the air so only the CO2 produced by the secondary fermentation will fill the space, or will it reduce pressure as the vacuum has to be filled by the CO2?

[trucker5774]

Thanks again Chris. If Ive got it right you are saying the O2 in the head space is actually require by the yeast and it would be detrimental to create a "vacuum" as the vacuum would take up the pressure and thereby reduce the ability to carbonate...........Just a thought.............should probably give up on this thinking stuff and go to bed, after all, I have been sampling the products!

[AlexCricket]

I think that it is a classic case that afflicts all us brewers - we try to overcomplicate matters.

I do however remember reading somewhere about the relationship between headspace and carbonation. Too much and the yeast can create too much pressure and blow the bottles too little and you end up with flat beer.

[Lillywhite]

Too much and the yeast can create too much pressure and blow the bottles too little and you end up with flat beer.

And the amount of priming sugar added should be factored into the equation.

[trucker5774]

The obvious next question is what would be considered the optimum head space/sugar combination and in what type/size of bottle

[Lillywhite]

15mm, half a level teaspoon, 500 ml or one pint dark glass bottles.