Quin wrote:Are you referring to head space? The empty space above the beer?
If the reference is simply to the head space, that is no problem during primary due to the amount of CO2 given off.
Head pressure as I described it above refers to the effect of increased CO2 pressure on yeast growth. The higher the pressure the slower the growth. This will only occur in a sealed fermenter (or insufficient venting in a fermenter).
Wayne
Bugeater Brewing Company