Acetaldehyde?

I am not sure if this is what I am detecting, but in my last three batches I have gotten this overly sweet fruity aroma and taste. The smell and taste overpower all other characteristics.

I am quite distressed by this. I have been using extract kits. The first 2 of 3 batches were fermented too warm (they were lagers), so I initially thought these off flavors were "fruity esters" due to high fermentation temps.

The last batch was the Northern Brewer Black IPA recipe...an ale, which was fermented at proper temperature. Primary fermentation was for 2 weeks, with 4 weeks in secondary. Beer has been in bottles for 2 weeks and there is very noticeable sweet/syrupy aroma and taste, very fruity (but not positive it is "green apples"). Final Gravity was 1.015 from 1.078, so I feel that fermentation was complete. A yeast starter was used on this last batch.

I have only noticed this taste since I started using secondary fermentation in search of clearer beer...

Whenever I pop the top of the fermenter I get a huge whiff of this smell also, but I do NOT taste it in the beer before bottling.

I have used both priming sugar and DME to prime, same results.

I have been agonizing over this and come up with a list of possibilities:
- not enough time in bottles (green beer)
- removing from primary or secondary too soon
- using LME
- not doing full boils
- aeration or infection during transfer
- underfilling bottles

I have this in bottles currently. Is there any chance simply leaving the beer in the bottles longer is going to help?

Should I not be doing secondary to minimize the chances of aeration?

I would like to enjoy my beer again. Please help!!!!!

This is complicated...I think it depends on each individual recipe. But the main thing is that you should really like the beer before you move on to bottling. For now, try to condition your current batches....in future, only bottle when you really like the beer. When you begin to get more comfortable with the brewing process, then you'll find beers will be ready quicker: for now it's not surprising that you may let your batches mellow for a few weeks.

Which yeast strains are you using that gives you the fruity flavor? And at what temperatures do you pitch the yeast, and ferment the beer?

Have been using a range of yeasts...it seems to happen with all them. The 2 lagers were dry lager yeasts "that perform well at ale temperatures". Since then I have stopped using dry yeast. The Black IPA recipe was with Wyeast 1272 American Ale II Yeast, with a starter.

More distressing - I popped open an older brew in which I did NOT detect the off flavor. Now I detect the off flavor in that brew as well (it was a pale ale with 5 months of age) whereas I didn't taste it before. It is not as cloying as the other brews, but it is still there.

I'm beginning to think my palate is ultra-sensitive to this particular taste now.

Sorry, forgot to mention, fermentation temps have been in the 60's.