There's nothing wrong with your beer, it's not overprimed nor is it infected...the problem is
YOU'RE OPENNING THE BEER AFTER BEING IN THE BOTTLE ONLY 4 DAYS!!!!
Watch poindexter's video from my bottling blog.
Like he shows several times, even @ 1 week, all the hissing, all the foaming can and does happen, but until it's dissolved back into the beer, your don't really have carbonation, with tiny bubbles coming out of solution happening actually inside the glass, not JUST what's happening on the surface.
The
3 weeks at 70 degrees, that we recommend is the
minimum time it takes for average gravity beers to carbonate and condition. Higher grav beers take longer.
But until then the beer can even appear to be overcarbed, when really nothing is wrong.
A lot of new brewers who tend to kill their two cases off in a few days, don't experience true carbonation and the pleasures thereof, until they actually get a pipeline going, and have their first 5 or 6 week old full carbed and conditioned wonderfully little puppy! Then the come back with an "aha" moment.
Everything you need to know about carbing and conditioning, can be found here
Of Patience and Bottle Conditioning. With emphasis on the word,
"patience."
Makes sure the beers are minimum of 3 weeks at 70 degrees before you even think of opening them, then make sure a couple of them are THOROUGHLY chilled for at least 48 hours to draw the co2 into solution. Then more than likely everything will be hunky dory....
Had you opened them after 3 weeks you never would have noticed anything wrong.....