Expert: Keith Patton - 10/9/2011

Question
We used a Mr Beer kit to make pale ale and it turned out super carbonated.  We followed directions and left the brew in the plastic barrel for more than the prescribed time and did the same after transferring it to the plastic bottles.  We chilled one bottle in the refrigerator for 2 days before tasting it, and it was as fizzy as champagne.  Can you please advise?

Answer
Rudy:

There are a number of things that may account for this.  The solution is to bleed off a little of the pressure by chilling the beer as cold as you can get it, then crack the tops of the plastic bottles or barrel and let the beer sit for a while and slowly degass, then reseal.

What could have gone is an infection.  Yeast can ferment or what we call attenuate the wort, the unfermented beer, up to a point.  This point is controlled by a number of things.  The first is the temperature of the water used to mash the barley.  Since you were using extract, that should not have been the problem.  If a low temp is used in a mash a wort that can be more fully attenuated is the result.  The Yeast can ferment it out to a greater degree.  A higher temp results in a lower attenuatable wort.  This is all due to starch break down or lack thereof and formation of complex sugars...carmelized sugars.

Some of this can occur in the boil as well.  But that would have had the opposite effect: resulting in a sweeter more full bodied beer.

If you used the yeast recommended or that was supplied with the kit, it should have attenutated the beer the proper amount.  Did you happen to ferment the beer at a higher than recommended temperature?  Some times the yeast can go nuts if the temp is high and it will push the attenuation beyond the target.

I have not brewed using a kit in about 20 years, but do know that in the enclosed type system you can exceed your carbonation mark by exceeding temp specifications.

The other most likely culprit is bacterial infection.  The beer will still be drinkable, but you might have what we call gushers.  Bottles with a slight infection will have too much carbonation, and some might have a "off" flavor, sulphury or skunky smell as well.  Some people have a high threshold for it and won't notice it, others will have a lower threshold and won't be able to drink the stuff.

When brewing beer in any fashion, santitation is paramount.  Santitize everything that comes in contact with the cooled beer, or what we call cold side.  The hot side takes care of itself.

Also, after the beer is chilled, keep it covered and get it inside the fermenter and pitch the yeast pronto.  Yeast handling is also critical.  If you had to mix up and hydrate dried yeast, used warmed bottled water, and a santized vessel for mixing it.  If not, you might have innoculated your beer with yeast AND bacteria.  Since bacteria can replicated faster than yeast, in a horse race, the bacteria would win.  Bacteria also will carbonate a beer, but not with just CO2 but with sulphur containing gasses as well.

So in my book it was probably a slight infection or a high fermentation temp.  If the beer is palatable, it is still drinkable.  Try the degassing.  If there is a slight odor or taste, try pouring the beer in a glass before drinking, a lot of the aroma or off taste will dissipate it you let it breath a bit...just like decanting a red wine.

Cheers.