Is hefeweizen yeast supposed to smell like rotting produce...

We've got a weizenbock that we pitched last weekend and I've got some questions because it smells terrible through the airlock.

Relevant information: White Labs Hefeweizen (WLP300) pitched @ 70 deg F into 1.071 OG wort, straight from the store-bought vial. It's something like our 8th or 9th beer.

Here's what happened: We (girlfriend and I) pitched the yeast and let it sit for a little over 48 hours, throughout which there was not a single iota of airlock activity. There was also no krausen formation in that time period. After the 48 hours, I cracked open the lid to give the wort a stern look and to see what was up, and lo, it still smelled that wonderful sweet smell of freshly boiled wort. Uh oh!

So I closed the lid again and after 24 more hours passed I peeked at it again (there was a minor bit of airlock activity at this point.) It looked like something was going on finally, so I was satisfied that the yeast were just being derpy and slow and left it at that. Fast forward a few days: The gas out of the airlock smells most foul, like a compost heap. I figure since I probably already ruined it by exposing to foreign air beasties, I can take the airlock off and take a quick draw (it's one of those "doubles as your bottling bucket" so there's spigot at the bottom) to taste test. A brew most foul! Rancid corn with hints of vomit. This was about 3-4 days ago.

This was our first time using this particular yeast strain, so I'm wondering if it just smells like this and over time gets better, or if I screwed up big by accidentally spontaneously fermenting/infecting the brew. So far, we're just letting it sit, with plans being to bottle it and see what comes. It is smelling a little better now, so I'm more hopeful than I was. What would you do in this situation, Ye Olde Brewers & Experienced People of the Trade?

Many wheat beer yeasts give off sulfur smells and tastes during active ferment. Was that it? Even if it wasn't, I wouldn't be too concerned yet. Fermentation is not pretty.

If you're using liquid yeasts, adding them into a starter first can get a jump start on fermentation. If you had an old vial of yeast, there was some loss of viability and a subsequent long lag in fermentation.

solbes said:

Many wheat beer yeasts give off sulfur smells and tastes during active ferment. Was that it? Even if it wasn't, I wouldn't be too concerned yet. Fermentation is not pretty.

If you're using liquid yeasts, adding them into a starter first can get a jump start on fermentation. If you had an old vial of yeast, there was some loss of viability and a subsequent long lag in fermentation.

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It's definitely not sulfur; we had a brown that turned out pretty good, but smell like Satan's toilet during most of its fermentation process. We've never had this set of smells before.

I should also mention that airlock activity is still going on pretty actively, which is also something that we've never encountered before (it usually dies off about 5 days after airlock activity commences.)

That is a long lag time. Well, what do you have to lose at this point? Let it ferment out and taste a sample before you bottle. If it doesn't taste good then chuck it.

Hef yeast is super sensitive to fermentation conditions. If you don't have temperature control and make a starter then you are going to have some serious ester problems. Your beer will likely come out drinkable but I doubt it will lose that funky taste. Next time make a 1.25 L starter or so and ferment around 63-64, you'll be much happier with the result.

beeber said:

That is a long lag time. Well, what do you have to lose at this point? Let it ferment out and taste a sample before you bottle. If it doesn't taste good then chuck it.

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Would letting it sit in primary for a few weeks longer than normal maybe help the yeast clear out any off flavors produced by bacteria, like single-celled wrecking crews? I would be happy even if it were spontaneously fermented vs. bacteria; at least it would be more likely to be drinkable then.

I've had hefes that taste like rotting green bananas, not my favorite but I like wheat beers so ya id say the yeast caused it, which could be the same thing u have

Most wheat beer fermentations for me have had vigorous yeast activity for 1 to 3 days after pitching with a big slow down after that. But that's mostly lower gravity brews like weizens, not a weizenbock. I am sure a higher gravity beer will take longer.

How long has this been fermenting now? Take a gravity reading if you can. Leaving it in the primary an extra week or three won't hurt anything, though if it tastes bad initially I wouldn't expect it to get "cleaned" up to any significant degree by the yeast.

beeber said:

Most wheat beer fermentations for me have had vigorous yeast activity for 1 to 3 days after pitching with a big slow down after that. But that's mostly lower gravity brews like weizens, not a weizenbock. I am sure a higher gravity beer will take longer.

How long has this been fermenting now? Take a gravity reading if you can. Leaving it in the primary an extra week or three won't hurt anything, though if it tastes bad initially I wouldn't expect it to get "cleaned" up to any significant degree by the yeast.

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It's been going for a week and two days as of today. I'll report on the scent once I'm home from work, the last time I checked the airlock was yesterday or the day before.

OK, it still smells like garbage, but banana-ey/clovey garbage. Airlock activity is going strong, which I find a bit weird after 5 days, bit I guess we'll see what it brings in a few weeks.

FYI, for WLP300 and 3068, especially if you are bottling, I'd leave it in the fermented for the normal 3.5-4 weeks. Lots of people on here say to do it shorter, but in my experience you get a better tasting hef by waiting. Don't judge anything on this batch though, you need a starter and cooler temps base case.