Increasing ABV with Hefe stuck at 1.018

[Brewdhomme]

Hey everyone,

On my 4rth all grain batch (Blood Orange Hefe), and having an issue with my SG. Wanted to get some feedback from the community. Here’s the details:

Brew Date 17 March 2013
Grain used (single infusion mash):
2 kg wheat
2 kg Two Row
500 g Vienna
Total grain bill 4.5 kg (9.92 lbs)
5 Blood Oranges and zest used in boil, as well as in primary.
Wyeast 3068 (1 L starter)
5 gallon batch
Preboil OG: 1.037 (after temp adjustment)
Postboil OG: 1.042
Current SG: 1.018

This is my second attempt at this Hefe, and I only slightly altered the recipe…however first time around it got down to 1.006! On this batch, when I saw my pre-boil OG was a low, I added some wheat DME (though only 100g) to the boil and boiled an extra 30 min which seemed to bump up the OG a few points. Anyways, Beersmith is showing a projected ABV of 2.9ish, which is way lower than I had hoped (was shooting for around 4.4% ABV). It has been in Primary since 17 March, originally at 19 deg celcius.. Bubbled away for 2 days, but then activity seemingly stopped, so I moved it upstairs hoping the 22 deg temp would kickstart the yeast back into hungry mode…no luck. I should mention that the yeast I used was from a 6 mth old starter that I never got around to using, till now. It smelled fine, so I decanted, and stepped it up with fresh wort for 2 days to 1 litre. Seemed healthy enough (nice krauzen in starter mason jar, looked active), so I pitched it and hoped for the best. Could it be that perhaps I did not pitch enough healthy yeast? I’d like to get it down around 1.010 for appropriate style ABV, but not sure if that’s even possible. Im considering following options:

-use another pack of liquid 3068?
-use a coopers dry yeast instead? (and save my 3068 for a new batch)
-use some wheat DME to brew up a mini batch and blend it with my Hefe (if so, how much should I brew?)
-perhaps add some honey (though, how much?) to boost the SG a bit (however, I wouldn’t want it to dry out my beer too much)

Any suggestions?

 

[anico4704]

Sorry if i missed this, what temp did you mash at? I would say most likely its due to mash temp or your 6 month old starter, thats pretty old, definitely past the best by date. Not sure if more yeast will work depending on your mash temp, but if your going to go that route i would go dry yeast as your flavor profile is already there for the most part. Adding sugar would boost the alch and make it dryer but i would suggest against that as that normally just ruins the batch. Personally i would shake up the carboy gently to get yeast into suspension again and maintain the top of the yeasts range and let it sit a week. p.s. try a hef at 1.012 fg it fits the style a lot better, 1.006 it pretty watery for a hef...

 

[BlackGoat]

first of all, your yeast were extremely old - there are a number of issues with using a starter that was prepared 6 months ago. Second, 1.006 is very very low for a heffe, I'm not sure how or why you got the beer down to that low of a FG the first time you made it, but 1.018 sounds not too far off at where I would have expected this beer to finish up. The problem of the low ABV isn't so much that the yeast isn't fermenting the beer further, to me its more that you started with a pretty low gravity and used old yeast that likely had a pretty limited number of viable cells which were not in great health. You can try to pitch some more dry yeast or something, but my guess is you might only get a couple more points of attenuation.

 

[Brewdhomme]

Okay thanks guys. Sorry - forgot to mention I mashed at 155 F (steady for the full hour). I had done some research on old yeast and figured I'd be able to rehab it by stepping it up over a couple days...guess I rushed it, or should've just used a new package. Yeah, my first go-round on this hefe last yr had an OG of 1.036 FG of 1.006...guess it was a bit watery, but was one of my first AG attempts. The wife still loved it, so thats why i was redoing it for this summer. Maybe ill try pitching a pack of dry yeast to see if that brings it down a bit - could it make the beer too "yeasty" i wonder? Regardless, beer is beer and it shall be drank!

 

[BlackGoat]

I wouldn't worry about it being too "yeasty" - especially with a heffe since that is kind of part of the style. Oh yeah, it certainly shall be drank, I'm sure it will still be delicious. Low gravity wheat beer would make for a great summer thirst quencher. Then again you're up in Canada so maybe your summers don't require as much thirst quenching as they do here.

 

[anico4704]

Ya greed the beer should still be very good

 

[rklinck]

Are you sure about your gravity readings? From what you told us, you ended up with about 55% efficiency. That seems low to me. I am also curious about the difference between your pre-boil and post-boil gravity. Is the pre-boil before you added the DME? I usually have more than 4 points difference in pre and post boil without adding DME.

 

[Yooper]

Okay thanks guys. Sorry - forgot to mention I mashed at 155 F (steady for the full hour).

That's why it finished at 1.018. A mash temp of 155 is pretty high, and will leave plenty of more complex long-chained sugars behind. That's an expected FG with a mash temp of 155.

If you want to finish lower, at 1.010-1.012, next time try mashing at 151/152.

 

[SmokeNbrew]

3068 is my favorite yeast for Hefe....ive noticed it really likes warm ferm temps tho. 70ish is what I stay at. I prefer the extra banana anyways. When temps fall into the lower/mid 60's activity slows way down. I fill the bathtub up with hot water, agitate the bucket and set it in there for an hour or more to restart the party. Then I stick it in the warmest place in the house (furnace room). Redneckognize.

Not saying this is your case... 1.018 is still okay tho.

 

[duboman]

That's why it finished at 1.018. A mash temp of 155 is pretty high, and will leave plenty of more complex long-chained sugars behind. That's an expected FG with a mash temp of 155.

If you want to finish lower, at 1.010-1.012, next time try mashing at 151/152.

I agree here and disagree about the yeast concern as you took an old starter and restarted it and stepped it up so in reality it was no longer an old starter

 

[Brewdhomme]

Are you sure about your gravity readings? From what you told us, you ended up with about 55% efficiency. That seems low to me. I am also curious about the difference between your pre-boil and post-boil gravity. Is the pre-boil before you added the DME? I usually have more than 4 points difference in pre and post boil without adding DME.

Yeah pretty sure about those readings (tho I find the hydrometer a bit of the PITA to read accurately - gotta get me a refracto) The pre-boil gravity was before adding DME (tho I didnt add very much).

Yooper - good point re: the mash temp. I'll try lowering it for the next heffe. BTW your posts are always super informative so thanks for weighing in!

Smokey - trying your bathtub resuscitation method right now! If that fails, I'll add a pack of dry yeast to see if I can get any action, and if not, i'll just roll with the weak beer as is...like BlackGoat said, will be a nice thirst quencher on hot summer days (and yes, Canada does get summer weather from time to time! Thanks for all the feedback everyone!

EDIT/UPDATE: so get this...after the 1 hour bath, i took a gravity sample before I was about to pitch the dry yeast. SG showed 1.005 (@ 29 celcius, due to bath...so temp corrected at 1.007!). Tasted nice and citrusy, and smelled rather boosey (poss the blood oranges contributing to that, as I had added 5 more blood oranges & zest a week ago). Beersmith is now giving me a 4.6 ABV...awesome! So, sounds to me like the week it spent in the warmer upstairs environment managed to wake the yeast up and bring the gravity down, even though i didnt see any noticeable bubbling. No need to add dry yeast now. I guess I just have to work on my effeciency and targeting the right mash temp for beer style. Thanks again for all the help all!