Help! Buttery, Banana Aroma from starter

Im about to brew a porter -- I made a nice .25 gal starter 3 days ago. The aroma from the airlock on the starter is like a strong banana/buttery smell. I know this can be caused by high temps. The yeast is White Labs Irish Ale. The room temp is 74 F. Should I use this starter? Will the diacetyl settle out or what? Do I need to get new yeast? I cleaned and sanitized my starter container with StarSan before starting. How do I know if this is contaminated or just regular diacetyl production? Should I pitch this to my beautiful virgin porter wort?


Thanks in advance!

can anyone help?

Banana is normal from lots of yeast strains. It is LEAVING the beer, so not a porblem. I dunno from buttery, never had that problem. But it is different from bananana.

I had a similar dilemma last week when I brewed my porter... my smack pack smelled funny when I I was making the starter.

My take on it is this:

The yeasy may have gotten to warm and produced some off-flavors in the starter's wort, but...

throw the liquid away. the yeast in there is just yeast... it doesn't have bad intentions, and it didn't MEAN to make your starter smell/taste funny.

So, if you discard the part that tastes/smells strange (the liquid), and just pitch the YEAST into your batch of beer, it should do the work you need and (as long as the temp is kept proper) the beer should come out just fine.

I'll be tasting my porter tonight as I rack to the secondary, so I'll write back and let you know if my theory holds up, or if my batch has off flavors.

-walker

Just pour off most of the liquid, swirl the yeast off the bottom of the container, and pitch.

That was the yeast I used in my last beer too. I did not have those smells though.

damn -- I pitched the liquid with the yeast too. Did not get your advice before I pitched. I heard that yeast has the ability to clear diacetyl smells though so I should be ok in time with this right? Ill just let it sit for awhile.

I had the same thing happen with a different strain of yeast. When I opened the package, it was downright foul smelling, after the starter fermented, it smelled like bananas, after the primary, it smelled/tasted like fruit cocktail (you know, the Del Monte kind?) after bottling and carbonating, it tastes great! So I wouldn't worry too much.

I was seriously tempted to toss the yeast when I opened it, but used my new mantra instead - What the hell, its only beer!

Walker said:

throw the liquid away. the yeast in there is just yeast... it doesn't have bad intentions, and it didn't MEAN to make your starter smell/taste funny.

Click to expand...

Good point Walker.

But since it is already piteched, I'd say don't worry. The yeast will consume (most of) the diacetyl once there is noting else left to metabolize. A good way of decanting the liquid is putting the starter in the fridge overnight. The cooler temps will make the yeast settle even though it is not done fermenting yet. Then you can decant the liquid and warm the yeast back up.

Kai

thanks for the bump here. I had said above (*) that I was going to write back with the tasting comments from my porter when I racked.

EXCELLENT!

I think I might have come pretty close to actually making my Holy Grail! I'm so freeking pumped... now I just have to wait 4.5 more weeks to drink it.

-walker

(*) = I actually have my forum preference set to show the most recent message at the top, so whenever you guys say "look at the post above" I sometimes get confused.