Sluggish Fermentatino

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Canuck Chuck

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Hello all,
I'm new to this group and I need a little help.
First of all, I consider myself an experienced all-grain brewer, but no master brewer whatsoever. I have built a HERMS and have been using it to make 10 GAL batches now for a few years.
I recently tried my hand at a lager (never thought the hassle was worth it), and I've got a stuck fermentation. It's been sitting there for over a month and the gravity is still at 1030. I used a Wyeast smack pack (American Lager).
I've got two hypothesis, the first is that I underpitched, the second is the I under-aerated.
What should I do?
I'm considering getting another smack pack, getting a starter going, then re-pitching. But I'm worried, wouldn't the low dissolved oxygen inhibit the propagation of new yeast cells?

Any help greatly appreciated, I'd hate to throw out 10 Gallons of beer!

Charles
 
Get another smack pac and use part of the wort for the starter. Since the cell count will be very high in the starter, the oxygen you put into it will be consumed rapidly. By using wort, the yeast will adapt to mix they will be fermenting.
 
Welcome fellow canuck.

1st it would be helpful to see the full recipie. What was the OG and did you make a starter and oxygenate your wort?

Adding o2 at this point would not be a good idea, but you can swirl your yeast to rouse it up a bit and see if it can get going again.

Also what temperture are you fermenting at? If you are using the WY2272 and are fermenting at from 48f to 55f you should be OK. If your actual temperture of your wort is lower than this, it will take a longer time to ferment out. You could try raising the temps a little as the peroid that affects the flavor the most should be past, and you shouldn't get any extra fusels or esters from the temp rise.

Hope this helps
 
At this point, I'd follow david's advice and make a starter from a new smack pack, and pitch that into the wort. They should make short work of it. But make sure that the starter is viable before pitching, or else you'll just exacerbate the problem. You might even let the starter and the wort warm up, then pitch, and wait until you see airlock activity before cooling it back down to lagering temps.

Don't aerate at this point, though...you'll risk oxidation on the final prod. In the future:

-First off, if you don't have an aeration kit, buy one. They're invaluable.

-Second, make a starter every single time, unless you're using an existing cake.
 
Thanks guys,
I've taken Dave's suggestion. I bought a new smack pack today and have drawn off some of my wort to use as a starter. Hopefully this should work.
To answer a few of the questions, my OG was 1052, mash temp was 148 for 90 minutes. The recipe was for a light lager (don't ask why), with pilsner malt as a base along with some flaked rice (about 25%).
I oxygenated for about 15mins after cooling to about 30C with a fish tank thingy.

I'm quite convinced that I underpitched, I've had ok success pitching just one smak pack for 10 Gallons of Ale, I guess it just didn't cut it for my lager.

Thanks a bunch!

Charles
 

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