Last night, I was trying to carry some bottles of my home-brewed beer in the basket of my bicycle. I only made it a few blocks from my home before I noticed that most of them were leaking. The caps were firmly on but most of the beer had escaped and made a mess.
How can I prevent this from happening in the future? This has happened once before with my own beer but never with store-bought bottles.
I am thinking of using bubble wrap or something to absorb the impact but I would like to see if anyone has any better ideas. Keep in mind that I am a brewing newbie so I don't know if the caps are on tightly enough, or if the beer is under too much pressure, or if there is some other problem.
EDIT: I am using some average-looking glass bottles that I bought from Brewcraft in San Francisco. They are not twist-off bottles. I am using a wing capper.