Fermentation Problem

Hey everyone,
I'm still fairly new to the art of homebrewing and I've got a question concerning a recent batch of ale that I made. It's been almost 4 weeks since fermentation started and there is still some minor activity in the secondary. It's not a ton of activity, it produces less than 1 bubble per every 10 minutes or so from the airlock. My question is that is it possible that something in my brew got contaminated, or is it entirely possible that the beer is still not done?
I didn't do anything different this time than my previous batches of beer, and all of those turned out great. The only difference this time is that my primary did develop a small crack in it sometime during the fermentation process. Any ideas?

-Shawn

 

Take a sample, use a hydrometer on it to see where it's at (check in a couple more days to see if it's moved at all between tests)... Then give it the old sniff and taste test. If it tastes good, then you should be fine. If it tastes like it's got something nasty in it (not in the recipe) then you probably got something bad in it from the crack.

How long was it in the primary from when the crack formed until you racked to secondary? How large of a crack are we talking about? Assuming that was a glass primary, I hope you're not using it for any more brewings.

I would be concerned that there's small glass particles in the brew. You might have left them behind when you racked to secondary, but the only way to be sure it either filter it, or rack a few more times, leaving at least 1/2" in the bottom of each carboy (giving it plenty of time to settle out between rackings)...

 

Not quite sure. My guess would be about 3 days since only a little bit of wort made it out of the crack.

Less than an inch in size.

It was a plastic fermenter, so no glass particles thank goodness. I will take a sample tonight and start to see if the beer has settled out. Thanks for the response.

-Shawn

 

I wouldn't worry about the crack's effect on this batch. Since it's fermenting there is positive pressure air flow pushing things out...so not much should get in.

I second the recommendations for taking a hydrometer reading. Even when airlock activity is stopped its not a reliable indicator of complete fermentation.

 

Since it was plastic, you should have less to worry about (particle contamination)...

A bit surprised you managed to crack a PET carboy though (or is this a bucket?)... How many batches have you run through that primary??

 

It was a bucket. I was thinking about replacing it, when it did crack. I've done over ten batches of beer in it.

 

The airlock isn't a good gauge of fermentation activity. I may have finished fermenting weeks ago, but there is still some dissolved CO2 coming out of solution. Check with the hydrometer.

 

Well I thieved out some of the beer last night, about 4 oz. and give it a healthy sniff and taste. Tasted like beer, smelled like beer, my conclusion, it must be beer. The hydrometer said that the S.G. was around 1.010, so I think that fermentation must be done, just some latent CO2 still creeping up from the yeast. I'm going to take some more S.G. readings for the next 2 days and see what I come up with.

Thanks for your help everyone!
-Shawn

P.S. Since I finally registered for this board I will probably lurk around here since I usually don't have to many problems. This one was the first!