Airlock stopped bubbling: classic noob question

I brewed my first batch of beer on Saturday--an IPA--and for the first two days the airlock was bubbling like crazy, but now, Wednesday, it has virtually stopped. I understand this is probably normal and I wasn't planning on racking to secondary for at least another week, maybe longer.

Anyway the temperature has dropped recently, to around 68 degrees, and I'm sure that may have something to do with it.

My question is, should i worry that fermentation has stopped too early and do something about it (crank the heat up? shake it around?), or just assume that it's still going but just not producing bubbles in the airlock? I know checking the gravity is an option, but want to limit the risk of infection.

Scratch that, I guess my question is: Is this normal?

Thanks - Any advice is much appreciated..

I think the general consensus is you are going to need to take a gravity reading to be sure. I have seen it asked many times on here and it always comes down to this...the airlock is not a reliable way to measure whether or not fermentation is taking place. I know it is a pain but unless I am wrong I think this is the only way. Maybe someone else can correct me if I am wrong but aside from a gravity reading with a hydrometer or a refractometer (and these aren't accurate once fermentation starts to take place, although there is a conversion to help get a more accurate reading) I don't think you will able to be sure that fermentation is stuck and/or finished.

Quite normal.

I have a spreadsheet for using a refractometer. Its here: www.clubhomebrew.com/refracto.xls

Grantman1 said:

Scratch that, I guess my question is: Is this normal?

Click to expand...

Also, I have had plenty of batches only show "airlock activity for 48 - 72 hours", and it still finished out at the targeted FG.

Just because the airlock stopped bubbling, doesn't mean that fermentation is over. Relax and don't worry. You say the temp has dropped recently to 68º. That is even pretty warm for some ale yeast strains. What was the temp before it dropped. Remember, the temp of fermenting wort will be a few degrees higher than the ambient temperature even. With high temps, fermentation happens quicker, but you also get some ester production that wouldn't have happened if you kept it down to recommend temp.

Also, just because the sugar to CO2+ Ethanol conversion is done, doesn't mean that the yeast are done with their job yet. They have some cleaning up to do. After about three weeks in the fermenter, take a gravity reading.

My air lock is not bubbling!
Maybe I am not looking at it long enough.
I took a gravity reading and it was lower than yesterday, but not at the target FG.
My airlock is not bubbling.