Many of us have at times started to panic a bit. Don’t panic—beer is very forgiving. Learn to relax—more beer is spoiled by first time brewers continually mucking aound with the beer than by accidental infection or other causes.
The common causes of panic
I pitched my yeast 3 days ago and the airlock still isn’t bubbling!
The number one call for help is definitely this one. 99% of the time the beer is fine and there is merely an incomplete seal between lid and fermenter or airlock and grommet and the CO2 gas is escaping there and not through the airlock. Take the lid off the fermenter and see if there is a head of foam (krausen) on top, or take a hydrometer reading and compare it to your first reading.
Sometimes the yeast has died and you need to pitch another packet. At the Jovial Monk we store a range of beer yeasts in the fridge to keep them at peak condition, and recommend you use them rather than the yeast supplied with the beer concentrate. Even if the yeast you pitched was dead you can repitch a fresh yeast a day or two after.
I pitched the yeast three weeks ago and the airlock is still bubbling.
Yeast will keep finding bits of sugar to chew on and will attack higher sugars when it has consumed the simpler sugars. Cold nights may cause the air in your fermenter to contract, sucking air in through the airlock. In the morning, as the fermenter warms up, this air may be forced out through the airlock, giving the appearance of a continuing ferment.
Your ferment is finished when your hydrometer records the same SG reading on two consecutive days, of about a quarter of your first reading.
Get the picture? Use your hydrometer not your airlock to gauge the course of your fermentation.
My beer has been in the fermenter for three weeks, is it still ok?
Your beer is fine. When the weather is cool, leaving the beer be for a week or two after the ferment has finished allows yeast to drop, fermentation by products to clear etc. Your beer will be much cleaner and there won’t be huge clumps of yeast in your bottles. There will still be enough yeast to put the fizz in your beer. To the contrary, leaving a fermenter full of beer for three weeks in our summers will likely put a distinct taste of Vegemite in your beer!