Unless you take a gravity reading you don't know what's really going on, not by airlock bubbling or by whatever you mean by the amount of foam. Neither of those signs are effective, they don't tell you exactly where on the fermentation process you are. The amount of krausen can vary for whatever reason, it can come quick and depart quickly or it can linger long after fermentation is complete, and it all be normal. And airlocks sometimes bubble or they don't.
If your airlock was bubbling and stopped---It doesn't mean fermentation has stopped.
If you airlock isn't bubbling, it doesn't mean your fermentation hasn't started....
If your airlock starts bubbling, it really doesn't matter.
If your airlock NEVER bubbles, it doesn't mean anything is wrong or right.
Your airlock is not a fermentation gauge, it is a VALVE to release excess co2. And the peak of fermentation has already wound down, so there's simply no need to vent off any excess co2.
Fermentation is not always "dynamic," just because you don't SEE anything happening, doesn't mean that any-thing's wrong,, and also doesn't mean that the yeast are still not working diligently away, doing what they've been doing for over 4,000 years.
That's why you need to take a gravity reading to know how your fermentation is going, NOT go by airlocks. The most important tool you can use is a hydrometer. It's the only way you will truly know when your beer is ready...airlock bubbles and other things are faulty.
The only way to truly know what is going on in your fermenter is with
your hydrometer. Like I said here in my blog, which I encourage you to read,
Think evaluation before action you sure as HELL wouldn't want a doctor to start cutting on you unless he used the proper diagnostic instuments like x-rays first, right? You wouldn't want him to just take a look in your eyes briefly and say "I'm cutting into your chest first thing in the morning." You would want them to use the right
diagnostic tools before the slice and dice, right? You'd cry malpractice, I would hope, if they didn't say they were sending you for an MRI and other things before going in....
Thinking about "doing anything" like repitching, or bottling, or racking, without first taking a hydrometer reading is tantamount to the doctor deciding to cut you open without running any diagnostic tests....Taking one look at you and saying, "Yeah I'm going in." You would really want the doctor to use all means to properly diagnose what's going on?
Fermentation is thought to have finished when the gravity has not changed for 2 readings over three consequitive days. So like other's have said, take a reading and you'll know where the beer is at.
We really can't help you without knowing what you beer is really doing. And the only way to know that is by telling us what the gravity is.
And the "magic" thing about this is, that 99.5% of the time when we tell someone starting a thread like this to take a reading rather going by airlocks or amount of krauzen, and they do, the realize that they worried and started a thread for nothing, that their beer is perfectly fine, and usually nearing completion.
