Fix for Hefe that is kegged and too sweet?

Our kegged and mostly carbed hefe is too sweet, to where it is barely drinkable. It was in primary for 17 days, and then went to a keg at kegerator temps and at 10 psi of CO2. I did not take any gravity readings, I know I should have. Could I do that now that it is carbed?

Recipe:
Specialty grains
0.5 lb Pilsner malt
0.5 lb Red wheat

7lb liquid wheat extract

Hops:
1 oz hallertau for 60 minutes.

If I could take an accurate gravity and its too high, I wonder if I could pull it out of fridge and repitch to give it more time, or is it too late?
If gravity is where it should be, maybe the recipe is sweet tasting because it only has the 1 oz of hallertau? Could I dry hop it?

Never keg your beer until it's done. But that doesn't help you now. If you warm it up and degass it, and pitch a very active starter, you might be able to get the fermentation going again.

I had an ESB that I messed up the recipe on. 3 lbs of amber instead of 3 oz. Needless to say it was too malty.

I transferred half of it to another keg (connect out side to out side and use low pressure in, then keep opening and closing the relief valve).

Then I brewed a "light" beer, nothing but pale malt and hops.

I then blended the two.

Now I have 10 gallons of excellent ESB.

That may give you some ideas of how to fix your problem.

Could it just be that the recipe calls for only 1 oz of hallertau? Can I take an accurate gravity after its carbed? I dont have any way to calculate/criticque the recipe.
No excuse for not taking gravities, but from what I've read 17 days is plenty for a hefeweizen. Airlock was going by 12 hours.

1oz of Hallertau may have been plenty, or not enough, depending on the AA% of the particular hops you used. AA% varies by year and growing region. How many IBUs did you recipe say to target? That's what I go by. If the recipe doesn't have stats for the beer, like FG, OG, IBUs, etc, I don't use the recipe.

To take a gravity reading, take some beer, shake it up, let it sit overnight, then take your gravity reading. You can't read it while carb'd. Also, the gravity reading by itself doesn't tell you much. The difference between how much it did ferment, and how much it could have fermented, is what makes the beer taste sweet or dry. Throw some bread yeast in your gravity sample and see if you can get it to ferment any lower.

Assuming you used WB-06 you should have a FG in the vicinity of 1.018. Follow Nateo's instructions and make some of the beer flat and take a gravity reading. If it is significantly higher repitch an active starter and hope it takes. Failing that, follow cfonnes' idea.

Thanks for the suggestions. I will leave some out tonight and see. Or could I microwave some to out gas it?

I was thinking about a microwave mash tun the other day...


Microwave the gas out of it???? I've never thought of that but I think it should work. As long as you don't get it to hot you may not damage any yeast still in suspension but I wouldn't count on them doing much. As someone else suggested - you could warm it up to 65 ish and then pitch some more yeast. I doubt it is a problem with the hops if this is a 5 gallon recipe, 1 oz of hallertau sounds about right. It is most likely an incomplete fermentation.

Now if you can just find a microwave to fit 5 gallons of beer...

Nateo's right but there may be another issue. What yeast did you use and what was your fermentation temp? Hefe yeasts can create sweet tastes though they usually also taste like bananas or cloves when they do.

The temp was in the high 70's. I'm concerned my now fermenting batch started too high, too (ambient was around 78) until I moved it. Maybe this explains the taste. I was using Safbrew's wb-06
I was only thinking of microwaving a small sample to degass it for the purpose of taking a gravity. I was under the impression that the carb level wont effect my ability to restart fermentation with a yeast starter, if I need to.

CO2 inhibits fermentation. That's why people use stirplates for their starters. You'll need to degas the whole batch if you want to ferment it more. That's why I'd do a forced ferment with your sample to make sure that you actually can ferment further.

I think it's probably your fermentation temps. If you check the boards for comments on that yeast you'll find it kicks out a fair amount of clove ester. High fermentation temps usually enhance ester formation. I've never used WB-06 and I obviously can't taste your beer but I'd guess interpreting the clove taste as sweet.

The gravity was under 1.015. I suppose this means I either didnt get good utilization from my hops, or esters from the too warm fermentation.

Did you try to ferment your sample further? The difference between apparent and potential attenuation is what makes it taste sweet, not the FG. I've had Saisons finish at 1.004 that tasted sweet and other beers finish at 1.010 and taste dry.

Without doing a forced ferment test you have no idea if there are still fermentable sugars in the beer or not.

no, i did not. i'll give that a try. I've been snooping around here for weeks, but I never caught that difference. i thought (OG-FG) x 133 was the ABV%, and attenuation was the ability of yeast to get the FG low. still learning

One other suggestion... 10 psi for a wheat is way too low. If you're at 40 degrees you want to be around 18 psi for that beer. The CO2 will make it taste more crisp and (might) make it more drinkable...

Recipe sounds fine, and although 1.015 is too high, my money is on not enough CO2. (I just had this very same issue)

Beersmith is showing an FG of 1013 for the recipe. The Hefe I'm drinking right now is about 1014 and isn't sweet at all. In fact, it's dead-on what I was looking for.

I'm pretty sure fermentation is over. Upping the CO2 pressure may help but I'd like to hear more tasting notes from the OP. Are there any flavors other than just sweet you're detecting? I'm still betting you're tasting clove (bananas are too obvious) and confusing it with sweet.

BTW: your ABV and attenuation definitions are correct.

For future reference, here's a link to forced ferment tests. FFTs are the only accurate and objective way to know what your FG should be:
http://braukaiser.com/wiki/index.php/Fast_Ferment_Test

Unfermentable sugars are not really sweet, except for lactose, which is sort of sweet. But the big unfermentable sugar in beer is dextrin, which is widely thought to provide sweetness and body. Charlie Bamforth did (or cited, IIRC) a study where they took basic pale lagers and add dextrins to the beer until they got to the taste threshold. It took a tremendous amount of dextrin added to the beer for the judges to notice a difference in sweetness and body, like way more dextrin than you'd ever have in a normal beer.

Fermentable sugars taste quite sweet. This is why a cider at 1.000 can still taste sweet, while a beer that low would be bone dry. This is also why people use less attenuative yeast to make sweeter beers like sweet stouts. In those beers you want to leave some fermentable sugar for sweetness.

Here's a quote from Kai:
"Sometimes, the yeast may stall before reaching the targeted FG (based on the fast ferment test result and yeast performance expectations). In this case you can accept it and fix it with the next batch (better aeration, other yeast strain, temperature) or try to kick start the fermentation by warming it up, rousing the yeast or pitching fresh yeast. I have done the latter when I found that a beer was still too sweet but the yeast didn’t want to attenuate further. The knowledge of the limit of attenuation and a measurement of the attenuation of the beer confirmed that the yeast can go further if I help it along."

That is a great link Nateo. I'll have to start doing that for my future brews, especially the big ones.

Forced ferment tests aren't very well-known among homebrewers, but they're pretty easy, and could answer every "is my beer done" or "is my fermentation stuck" question you see on here every day.

From my experience, stable gravity readings for multiple days or the krauesen dropping aren't good metrics for judging if a beer is done fermenting. I've had too many batches seriously overcarbed or underattenuated that way.