Getting gushers is an unfortunate but not unknown occurrence when buying bottles from
Basically what you need to do is release the excess pressure a bit at a time. Back when I started home brewing digital scales were not the sort of thing you found in a kitchen so excess priming sugar and the inevitable gushing that follows happened all too often. Fortunately there's always a slight pause before a gushing beer can build up a head of steam, and it's thanks to this that the situation can be saved.
Take a broad headed bottle opener and slightly ease up the crown cork until the bubbles start to build. Let them slowly rise up the neck of the bottle when they reach the stop lifting the cap. Often the bottle will re-seal, but if it doesn't you won't have a horrible mess, or even worse a big waste of beer, you'll have foam oozing out from under the cap. Now's the time to grab your bottle capper and clamp down the top. The oozing will end and peace shall come to everyone.
|I added Brettanomyces to this beer and then bottled it too soon.|
This process will need to be repeated numerous times as only a small amount of carbon dioxide will be vented each time. So let the beer settle down and then do it again, a few times a day, for a few days. Eventually the bubbles will lose their ferocity and the beer will be safe to open and drink in the usual manner.
If the situation is really bad put the beer in the fridge before releasing pressure as colder beer will absorb more CO2 so will be less lively.