Repitching Yeast of Beer with Acetaldehyde Taste/Flavor

[JollyToper]

I over-pitched my first beer and even after 12 days in the fermentor it is going to need some time to get rid of the green apple smell and flavor (in the keg).

The yeast slurry smells the same way and I planned to repitch it into a fresh batch of wort (not the whole thing but the right amount estimated using MrMalty).

I'm thinking that the yeast will clean up the new beer just like the first beer.

Am I thinking about this the right way? Thanks in advance.

JT

[jamilz]

Not sure what you mean by "just like the first beer."

If you pitch the correct amount of yeast, correct level of O2, right temp, and don't separate the yeast from the beer too early, you should have no trouble with acetaldehyde.

[ajdelange]

It's generally difficult for a homebrewer to over pitch. I'm not saying it can't be done but where acetaldehyde is strong enough that it's the first thing you notice I have to suspect bacterial infection. If this is indeed the problem reusing this yeast might not be such a good idea.

[JollyToper]

Not sure what you mean by "just like the first beer."

Yes. My post wasn't very clear. Here is the full story.

I brewed your Scottish 80 recipe (clearly not brewed with your skill) and I'm getting a green apple taste after 12 days in the primary. I made a starter appropriate for a 5.5 gallon batch, gravity of 1.050, and using a stir plate. While I hit my OG I only put about 4.5 gallons in the carboy. I'm also wondering if I should have used a starter at all. I got the impression that when you said not to make a starter on the Scottish 60/70/80 show you were referring to the 60 and 70 which are lower gravity. FWIW, I used 50 second dose of O2 from a Home Depot O2 bottle.

My hope is that the 80 will clean itself up with time. It is in a keg now but I have not filtered it. If it does not clean up on its own I was planning to add a little healthy yeast back in. I need to find the show where you told John how to do that.

Not being able to get to the LHBS for a couple of days, I repitched the yeast from the "appley" 80 into a blonde (I know its the wrong sequence SRM-wise) and am hoping that I didn't just waste another 5G of wort.

Am I screwed?

Thanks,
Dan

[JollyToper]

It's generally difficult for a homebrewer to over pitch. I'm not saying it can't be done but where acetaldehyde is strong enough that it's the first thing you notice I have to suspect bacterial infection. If this is indeed the problem reusing this yeast might not be such a good idea.

Doh! I hope that is not the case in this batch. If so, I just wasted another 5 gallons of wort. See my longer reply to JZ above for additional details on why I think/hope it was an overpitch versus an infection.