We're currently trying to get a lager to go through its primary fermentation but after 2 days, we haven't seen any action or changes on the surface of the wort. The wort had a full packet of yeast that the brewing store guy said is more than enough for the fermentation. Another fact is that the lager is kept in an environment around 45F, several degrees lower than the ideal 50F which might be slowing the process. I'm wondering if this is common in bottom fermentation or the yeast maybe dead in our case; compared to the top fermentation that we've tried previously to make an IPA which showed an immediate and noticeable reaction within 12 hours.

  • Are you certain the yeast was a lager yeast? Some lager beer kits actually use ale yeast, which becomes very sluggish below 60 F. Dec 9 '14 at 14:54

Take a gravity reading. Visual inspection doesn't tell you much about whether fermentation is happening or not.


Assuming that your yeast was alive, 45F is a bit on the cold side to start. I would bring it into the house to get it to "go off", and then take it back to your cold room once it starts fermenting.You may also have "shocked" the yeast if your wort was a bit hot when you pitched. If so, there may not have been as much viable yeast left, and it would take a while to come to life. 48 hours is a long time though, and you are in danger of a bacterial infection overtaking the yeast.

You may want to get a new yeast packet and rehydrate that to be ready to pitch as well, just in case you had a bad batch.

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