Beer not finishing to expected FG.

[Adam]

Looking to have some help figuring out the cause of finishing higher than the recipe calls. This was brewed on the 18th.

Recipe was a dunkelweizen extract kit with steeping grains. Expected OG was 1.049-1.053 to finish at FG of 1.012-1.015. Actual OG was 1.052 and FG was 1.023. Both actuals were temperature corrected.

The wort was cooled to 70 degrees, yeast was 2 packs (22g) Danstar Munich Wheat, rehydrated into 75 degree water and pitched after 15 minutes. Within 12hrs, wort cooled to 67 degree fermentation temperature and airlock activity began. Airlock activity for first 48 hours. I took SG readings Saturday, Sunday, and Monday. All were the same, so fermentation is complete. When I lifted the lid on the bucket, the krausen only reached an inch or so above the wort level. Airlock activity meant the fermentation bucket had positive pressure, pushing out air and filling the headspace with CO2. When airlock activity ceased, the yeast calmed down and began to work slower and clean things up.

After my hefe brew, it was suggested that I pitch more yeast since I'm not doing starters. I did that and now I'm thinking 2 packs was too much. The whole supply/demand principle. With twice as much yeast there is more competition for nutrients in the wort to be consumed before the yeast consume the sugar compounds, of which still twice the amount of yeast are competing to eat. One theory I've been entertaining is the yeast was stressed out due to competition thus not allowing enough healthy yeast to do the job, and dying off or becoming lethargic before optimal SG is reached. Plausible?

[BeerPal]

...I'm thinking 2 packs was too much. The whole supply/demand principle. With twice as much yeast there is more competition for nutrients in the wort to be consumed before the yeast consume the sugar compounds, of which still twice the amount of yeast are competing to eat. Plausible?

Umm... no.

[Bugeater]

About the only effect of overpitching is that you won't have the yeast producing the normal esters that you want in a beer, especially in a hefeweisen. The culprit here is probably the extract in your kit. Some brands of extract have a high amount of long chain sugars that are hard for the yeast to digest thus leaving your final gravity higher than expected. These brands of malt extract are designed for use in recipes that use sugar as a significant part of the fermentables. Since the sugar is almost completely fermentable, there is a need have an extract that is less fermentable so the beer doesn't finish too low. Kit designers often fail to take this into consideration and you can see the result for yourself. The most problematic of the extracts are Laaglanders and, to a lesser extent, John Bull. Both are quality malts but need to be used in combination with sugar to get the desired FG.

Wayne

[brewinhard]

I wonder what extract was used for this brew?

I have read of overpitching resulting in underattenuation before though. I believe it was from a thread posted here. 2 packs of dry yeast would be overkill for a 1.052 batch.

[Quin]

You didn't mention how you are aerating your wort. Most incomplete fermentations are due to a lack of oxygen.

[dmtaylor]

It's the extract. It's almost always the extract.

Sorry, I haven't been drinking. I'm just feeling bitchy today. But it's true though. It's the extract.

[iophon]

So you fermented this for 10 days total? If so I would suggest you wait at least another week. 21 days is my minimum, I don't even look at the beer till then.

Also yes 2 packs was too much. And while I am answering (!) you might want to get on their web site to get some answers as well as proper re-hydration instructions - I doubt if it was a factor but you should rehydrate closer to 90 F.

Iophon

[Adam]

Ingredients:
6.6 lbs Breiss Bavarian Wheat LME
1 lb maltodextrin
8oz chocolate malt
8oz munich malt
.5oz Willamette bittering hops (4.7% AA)
.25oz Cascade aroma hops (5.0% AA)
Danstar Munich dry yeast
60 minute boil

Target OG: 1.049-1.053
Target FG: 1.012-1.015
IBU: 10-13
ABV: 4.75-5.25%
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When I transferred from kettle to fermentor, I used a siphon. I was not aware aeration of wort was a good thing. I was under the impression aeration and oxidization were equally bad for wort. Now I'm confused.

As for 2 packs of yeast, JP advised it during an exchange on FB. I just found JZ's site and it says only 1 pack. Fuck.

Yes 10 day fermentation. Today is 12 days. Everything I've read about German wheat beers is no longer than 14 days in fermentation before bottle conditioning.

I'm told one of the best domestic extracts is Breiss.