Stuck Fermentation - A Quick Re-pitching Question...

....well maybe not so quick.

Hey guys! I've been lurking for a while since I discovered this site and its about time I made a post. I'm a n00b and just brewed my second batch but I've been reading everything I can, and as a geeky engineer I'd like to pretend I know what I'm talking about.

Okay. My first batch was a True Brew IPA extract kit from a local beer supply shop. My initial gravity reading was 1.051 which was spot on but my final gravity reading was too high. 1.019 and holding steady after two weeks in the primary. I transfered it to a secondary hoping some magic would happen but no change...surprise. I've now learned where I went (mostly) wrong.....I didn't aerate enough. I just sloshed it around 2-3 times to "mix" things and considered that aerating. Wrong.

And then this....
https://www.homebrewtalk.com/f14/stuck-fermentation-repitch-97760/

After reading through that thread I'm considering transfering the IPA onto a yeast cake. I have a few general and timing questions. I have a batch of Northern Brewer's American Hefeweizen that is just finishing up in the primary after 2-3 weeks and will go straight to the bottle. Can I use this yeast cake to transfer the IPA onto? Or is that a no-no and I'm likely to ruin my IPA since its two very different beers? Or am I totally off and not even grasping the concept?

As it stands, the IPA tastes pretty good (well maybe a wee bit watered down) and the ABV is 4.3%. Should I just call it a "light IPA" and chaulk it up to experience or should I transfer it onto the Hefeweizen yeast cake?

Thanks in advance guys and sorry for the long post!

Don't pitch on the Hefe yeast, totally different style, it will come out rather strange if you do that. Depending on the type of extract used and the amount of unfermentables in the recipe, your beer might be as low as it will go. However, it will not hurt anything to pitch a packet of dry yeast to try to get it to ferment out a little more. At this stage I would recommend using Nottingham or Safale-04. Safale -05 is another option but because it is slightly less flocculent, you may end up with a yeasty flavor in your finished beer. My first choice would be Safale-04.

Good luck!

Thanks for the reply! I actually happen to have some Safale -05 on hand. If I were to give it a shot would it be worth it to not only rehydrate it but to introduce some of the IPA gradually to get the yeast use to it? Or should I sprinkle some on and be done with it?

My palette (sp?) is just learning so I'm not too in tune with the finer beer flavors....but is your opinion that the flavor from the Safale -05 would degrade my beers flavor? Or is it somthing I probably won't even notice at this point. If it will be noticeable, I could make a trek to the brew store even though it is a pain.

If you have 05, just use it. Definitely rehydrate though. When I use 05 now I always use gelatin and cold crash to make the yeast settle out. It's awesome stuff but doesn't floc all that well. Also, I'm a big proponent of "primary only" brewing but this may be a case where the beer would benefit from racking to secondary before pitching the new yeast. I would bet that you will drop 4-5 points over a few more weeks. Again, it depends on the unfermentables in your original wort. Don't aerate before the second pitch, it will cause oxidation at this point. Get yourself an O2 regulator, carb stone, and 02 tank like this: http://morebeer.com/view_product/16604//Oxygenation_Partial_System . You will avoid a lot of future hastle.

Don't just pitch in a packet of yeast. It will likely just settle to the bottom of your fermenter and not do anything. I would recommend making a small starter full of yeast nutrients and well aerated. Once your starter is at high-krausen pitch it into your already partially fermenting beer.

Stuck fermentation can be a result of old/not viable yeast or not enough nutrients in your beer (amino acids and nitrogen) not pitching enough yeast, not aerating the wort enough, and temperature changes.

Adding more yeast to a stuck fermentation doesn't always work. Making a starter to get the yeast active and healthy again gives you more of a fighting chance.