Is there any reliable information of what the real impact is of contact between air and beer after primary fermentation is over? Say, I brew a simple IPA. After primary fermentation I put half of the beer in a fermentation bottle that becomes half full, and the other half in a fermentation bottle that becomes completely full. So in the first bottle the contact surface between air and beer would be much greater than in the second. Suppose I don't stir or do anything else really stupid, would there be a big difference in taste between the first beer and the second, i.e. would the second beer have a more pronounced oxidized taste?
Asking this because I'm still a novice, and up to now I haven't paid much attention to this issue.
BTW, what a lot of people in Belgium seem to do when they are lagering their beer is to add a lump of sugar. This would then ferment and create a "CO2 blanket" to protect the beer against oxidation. Does this work or is it a myth?