This is a good thing, right? (fermentation & airlock activity)

[surista]

I've made 7-8 batches or so over the past year. All have been very drinkable, liked some more than others.

I usually get about 36 hours of visible/audible airlock activity, then it dies down. I know it's still fermenting, just that there's no visible airlock activity after the second or third day. This has been the case for all my beers. I usually leave it in the primary fermenter for 2-3 weeks before bottling.

I brewed last Sunday (1 Aug). It's now Saturday - and the airlock is still bubbling away about once or twice a minute. It's the same brand of yeast I used three weeks ago (bought at the same time). Close to the same recipie from three weeks ago. Same fermenter. Only difference is I moved the fermenter into a different corner of the same room. It's been mildly cooler the last week compared to my beer three weeks ago.

I'm assuming this is a good thing? Could it just be that I have a better air seal this time?


FWIW, here's my recipe:

Windsor Vienna Lager
Caramalt 200g (0.45lb)
Vienna Malt 800g (1.7lb)
Lager Malt 800g (1.7lb)
Munton's Dry Amber 500g (1.1lb)
Munton's Dry Light 500g (1.1lb)
Munton's Dry Extra Light 500g (1.1lb)

Mash/steep grains in 2 gallons of water @ 67* C. (153* F) for 1 hour
Remove grains, bring to boil
Add 15g (0.5oz) Northern Brewer hops & the dry extract
At 30mn add 15g NB hops
At 60mn at 5g Hallertau and take off heat
Cool to 32-34* C
Top up to 5 gallons with chilled bottled water, brings water down to 21-22* C
OG = 1.047
Add S-189, aerate, and seal.

 

[jeffmeh]

Yes, all good.

The biological processes of fermentation operate within the framework of chaos theory, i.e., "sensitive dependence upon initial conditions." In other words, any small difference between batches can create radically different paths to even an extremely similar finished beer. And even more simply, yes, the cooler fermentation temperature will result in a relatively longer fermentation. Wait your 2-3 weeks and take a hydrometer sample.

 

[Babylon]

I would say it is neither good nor bad. Just a slower ferment. That should mean a cleaner beer, with less esters, which can be good or bad depending on what you are going for.