Very interesting stuff Mark - did you find much in common with the ones that were sour &/or over-carbonated?
E.g. You seem to suggest a link between these two? (sourness & overCO2d)
This would make sense as wild yeasts, bacteria, etc can ferment beer further than ordinary brewing yeasts, making it fizzier, but also creating acid in the process (e.g. lactic or acetic).
Was there anything in common between the 'problem beers' - were they all/mainly from smaller micros?
Do you know the bottling/preparation methods for the problem beers / good ones? (filtration, sterile/rough, fining, krausening, centrifuging, etc)
I haven't yet got a copy of GBBG, so I prob won't know this info myself.
As someone who is trying to work out how to set up a commercial brewing co. including bottled beer, using small breweries' spare capacity, I am very interested in all this.
Comments/experiences very welcome from anyone else too, here or email is fine, if so please use the following address, not the newsgroup one mic_mac (at) postmaster (dot) co (dot) uk cheers MikeMcG.