dreaded stuck fermentation

[MidnightShift]

I have a porter that has been in the fermentor for 3 weeks with an OG of 1.063. It is stuck at 1.030 for the last week. I have raised the temp and roused the yeast but no luck. Tomorrow I am going to be racking an amber ale and was wondering what would happen if I were to put some if the yeast cake from that into the porter? What is the best way to go about it, how much should I re-pitch and what effect will it have on the porter?

Thanks in advance.

 

[nilo]

What is your recipe? Mash temp?

 

[MidnightShift]

It was an extract recipe. I just used the wrong yeast. I used muntons yeast and after looking at their website I realized that it was not the best for malt extract.