Should I Re-Pitch?

Hey guys,

I’m a fairly new brewer so bear with me a little.

48 hours after pitching the yeast I have not seen any activity in the airlock. During the first 24 hours there was quite some activity inside the carboy but I never saw any bubbles going out the airlock.

Could it be that fermentation is over? Rather strange because I’ve been sticking to the same process and recipe for a couple of months and this had not happened before.

Could it be that the yeast was not properly rehydrated or pitched and it died? How do I determine if I need to re-pitch some new yeast?

Bubbles in the airlock are never a good indication one way or the other. Is there (or was there) a krausen of yeast at the top at any point? If so, its possible that fermentation is complete.

What was the recipe, what type of yeast did you use, and what temp did you pitch at?

Are you using a bucket? Lower CO2 pressure from a slowing fermentation may not push out through the air lock, but may be escaping around the rim of the bucket.

I was under the impression that if the airlock’s function was to release gases in the form of bubbles during fermentation.

After the first 24 hours there was, but not anymore.

The yeast was Danstar Nottingham Ale Dry Yeast and I did not take a temp when pitching, but it was probably around the high 60s to low 70s.

I’m using a glass carboy with a cap like this one

and a 3 piece airlock

The pitching temp might have been a bit high but with your replies I believe that fermentation did happen and that it has already stopped.

New question now. If fermentation is over, is there any advantage to leaving it in the fermentor for another week? Can I go ahead and bottle it?

Judging from your warmer than average pitching temps and using Nottingham which is a notoriously quick fermenting yeast I would say primary fermentation is probably complete but I would leave it in primary for another 2 weeks. Even though a majority of the fermentation is complete, the yeast is still going to work cleaning up the by-products of fermentation.

With regard to your comment on the airlock, that is it’s purpose but there are a number of reasons (including the one in flars post) why it may still bubble after fermentation, and may not bubble even when fermentation is not complete. The best way to determine if your fermentation is complete is to take subsequent gravity readings (2-3 days apart) and make sure there is no change between the subsequent readings.

Just FYI, those orange carboy caps have a tendency to leak. The oxygen transfer rate through them is pretty horrendous, too. It should be fine for a 3-4 week fermentation, but there’s a pretty good chance that CO2 is leaking around the edge of it.

I will leave it in the primary for 10 days, which was the originally intended time.

Is it ok to just open the cap and take a sample for the reading?

What would be a better way of capping the carboy? blowoff tube?

Thanks for all the useful info!

The universal bungs that fit inside the opening work the best for me. The rubber ones are OK, but they’re slippery and you can end up with one inside the carboy if you’re not careful. Makes for some great humor material though! At least for those of us that never matured beyond about 12 years old.

Is it ok to just open the cap and take a sample for the reading?
Thanks for all the useful info![/quote]

Yep, just make sure you sanitize anything that touches the beer from this point on. Depending on what you are using to pull a sample, make sure you sanitize it well. Also, don’t pour your sample back into the fermenter as this increases your contamination risk. I like to put mine in a glass and stick it in the fridge for a few hours to drop out as much yeast as possible and sample it to get an idea of what it’s going to taste like.