Could be lots of things. First off make sure you are in the right temp
range for your yeast. Next 4.75 is a touch high. Should work but you may
want to lower it. How did you determine your pH? Titration or Litmus
paper? If you have a titration kit follow the instructions on lowering
the acidity. If not, get one. You want to be between 5.5 and 5.0.
Considering you are shooting for a sweet stout try to get closer to 5.5.
If that does not help then there are other things you can try but they
put the wort at risk.

First off read this on line book:
[url]http://www.howtobrew.com/intro.html[/url]
Now if you used dry yeast make a starter and follow the suggestions from
the book.
Next determine your water chemistry and, if necessary, make adjustments
as detailed.
Finally you may have a lack of oxygen so you could try and rack but
instead of minimizing the splashing actually encourage it. This will
oxygenate the wort but you run huge risks with infection and off flavor
notes. But if you end up with no other option what have you got to loose?
There are other reasons that you see no progression but there is no
viable solution that I know off that will save your beer.

Maybe someone else will have additional tips.

Cheers,
Eric

PS next time instead of cocoa use a chocolate roast malt and crystal
malt combo. It will probably get you the flavor you were shooting for.



Walter Cronkright wrote:[color=blue]
> I recently modified a stout recipe that had previously been successful by
> adding 3 cups of cocoa (of uncertain origin) to make a chocolate stout. The
> bubbling was never very vigorous and stopped when he gravity had dropped
> from 1.050 to 1.030. I moved to secondary, waited 2 weeks, then added more
> yeast and waited another week, but nothing ever happened. Gravity is still
> near 1.030 but should be near 1.010.
>
> I've learned that some cocoa is "Dutched" meaning that it has been treated
> with alkali. I had the pH of my concoction measured and found it was 4.75.
> Is this a normal pH or is it too high? I would be grateful if someone could
> advise.
>
> Walter Cronkright
>
>[/color]