adding diffrent yesat to stuck fermentation

i brewed an IPA about a week ago and i think i have a stuck fermentation (1.045). i used dennys favorite from WYEAST . right now i have a london ale III
starter going . do you think i can pitch the london starter to the stuck fermentation?

before you use up your starter, have you tried rousing the yeast. Use a sanitised spoon and gently give it a stir to bring some of the yeast that may have fallen out back into suspension. Leave for a couple of days and test again.

maybe i will try that. would a different strain of yeast coexist with the original yeast?

You could pitch that starter, but with 1.045 left to go, I would expect it to contribute plenty of its own character to the beer.

Why do you think the original yeast have stopped working? Are they all dead, did you kill them somehow? Most likely, you didn't aerate fully and the yeast cannot continue. Pitching another starter might bring you down a bit since some of those yeast will be able to go for awhile with the oxygen from the starter. I would expect whatever is preventing the current yeast will prevent any follow on yeast.

Is this all grain or partial mash? If AG, what was the process, mash temp, anywhere during the process that something went wrong? Was the yeast old, use a starter, ect?

this was an all grain batch. i grew the the starter from a slant but because of lack of time i didnt wait enough time . 20 mil for one day 60 millileter for one day and one liter for one day. the starter was going but not going off big time like my other startes . mash temp was about 66c . og was ten points higher then i expected- 1.070

I would suggest pitching a dry yeast to salvage the beer. It doesn't need as much o2 as a liquid starter.

thanks. i think i will pitch the liquid starte (dont have dry yeast and my LHBS is far away)