Cold pitched a lager. When will I see activity?

[ajdelange]

Would a shot of O2 be advised at this point? (Approx 24 hours after pitching)

Hmm. I'd pull a few mL and check pH. If it is, say, 5.8 or less then fermentation is underway and all you need is patience. Assuming you do not have a pH meter then I'd look for the sparkling at the surface I mentioned. If you see any of that then fermentation is under way. If you do not see that then I'd put a few mL in a tube, cover the end with the thumb and give it a shake or 2. If this results it CO2 being released then the fermentation is under way. If there is no sparkling and no gas released on a shake test then fermation is not moving and I don't see how a blast of O2 could hurt.

[brewinhard]

I would say don't mess with it. Be patient for now. Did you aerate your wort? If so, how and how long? I am always wary of adding a second blast of oxygen.

[basilhays]

I was out of O2 and had to resort to splash and shake aeration. I just got home and have what looks like the beginning of a kraeusen forming. Guess I'll give it another 12 hours and see what tomorrow brings. Thanks.

[BigNastyBrew]

Most of my lagers' krausen starts off in little "dots" on top of the beer. Then, they just keep growing until they're conjoined and voila!

[basilhays]

I guess there is a fermentation god. Nice kraeusen forming this morning. I would like to thank the BN Army for the information and support.

[brewinhard]

Next time, invest in a good aeration system. This will make you worry/stress less and your fermentations will start faster and be more complete, especially lagers, and stronger beers.

[BDawg]

Next time, invest in a good aeration system. This will make you worry/stress less and your fermentations will start faster and be more complete, especially lagers, and stronger beers.

+1

[TheTodd]

Next time, invest in a good aeration system. This will make you worry/stress less and your fermentations will start faster and be more complete, especially lagers, and stronger beers.

+1

I'd have to agree. I just did my second lager (a German Schwarzbier) last week. I pitched a 2L starter that had been active for only a day into a carboy when I remembered that I hadn't aerated (read splashed around; no pump here yet). My solution was to shake the carboy every now and again. I didn't get activity for almost 48 hrs, but have had a nice steady ferment with a pretty 2in. thick krausen for the last 5 days. I'm sure I would have gotten much quicker results with a properly oxygenated wort.

I apologize to ubergeek AJ (thanks for your help on Brew Strong, by the way) for my barbaric ways, but I don't get to brew nearly as much as I'd like and tend to forget one or two basics between batches.