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General Category => General Homebrew Discussion => Topic started by: yaleterrace on March 01, 2011, 05:02:16 PM

Title: High Final Gravities
Post by: yaleterrace on March 01, 2011, 05:02:16 PM
Hey homebrewers.  I have been brewing for a while now (all-grain) and I have recently started running into an issue with my ales.  I keep winding up with high FGs, and seemingly can't bring them down.  I LOVE beer with a big body, so this isn't a problem until I shoot for a low FG I come in high.  For instance,

Saison: OG 1.064, FG 1.033
Brown Ale: OG 1.080, FG 1.041
IPA: 1.062, FG 1.027
RIS: OG 1.112, FG 1.052!

I employ a stepped infusion mash, and all of these had at least a partial A-amylase conversion at higher temp, hence more body, but they also all had a B-amylase rests.  My B-amylase rest temp is in the 146-148 degF range, and my A-amylase temp range is 158-160.  I have been using mostly Belgian Saison, Belgian Abbey Ale, East Coast Ale and Dry English Ale yeasts.  Can anyone troubleshoot my issues?  I feel like sooner or later my high FGs will make infection more possible and/or more noticeable and damaging.  Thanks & Cheers!
Title: Re: High Final Gravities
Post by: maxieboy on March 01, 2011, 05:05:12 PM
Have you calibrated your thermometer? Could be reading low.
Title: Re: High Final Gravities
Post by: yaleterrace on March 01, 2011, 05:06:55 PM
Yeah, checked the Blichman thermometer with a second Blichmann, a different dial thermo and an alcohol thermo...
Title: Re: High Final Gravities
Post by: bonjour on March 01, 2011, 05:24:25 PM
You are consistently at the same attenuation (+/-) with different yeasts.
This is either a measurement issue or a process issue.

Can you run a fast ferment test,  Take a bottle, dilute it by 50% in a growler, measure it then ad a packet of dry, not liquid or rehydrated yeast.  let it ferment (warm) and see what it stops at.

This is to determine if you have any fermentables left.

duty call, got to work.
Title: Re: High Final Gravities
Post by: tschmidlin on March 01, 2011, 05:24:51 PM
What are the recipes for those beers?   Have you changed malt?
Title: Re: High Final Gravities
Post by: yaleterrace on March 01, 2011, 05:30:07 PM
I'll try the quick fermentation test, tho I use dry yeast packets with healthy starters for anything I can, liquid when I can't.

As far as malt goes, I switched from Breiss US 2Row to Rahr US 2Row about 6 weeks back and brewed 4 batches with the same high FG issues.  The saison was brewed with unmalted wheat and oats as well, but no other adjuncts to speak of.
Title: Re: High Final Gravities
Post by: tom on March 01, 2011, 05:33:48 PM
No need to do starters for dry yeast. They can be detrimental.

What temperature are you fermenting at? How do you aerate/oxygenate your wort?

Have you checked the mash pH?
Title: Re: High Final Gravities
Post by: tschmidlin on March 01, 2011, 05:35:28 PM
I think there's a thread or two around here about Rahr . . . but I thought it was pH effects and high attenuation, not low attenuation.  I haven't used Rahr, so someone else will have to talk about that.  If the 4 batches where you've had the problem were all made with Rahr, and none of the ones you made with Briess had that problem, I would think it's the malt.  Is that accurate, or am I confused?

In either case, do the fast ferment test like Fred says.
Title: Re: High Final Gravities
Post by: denny on March 01, 2011, 05:49:14 PM
I use Rahr exclusively as my domestic pale malt and I always get the attenuation I expect out of it.  Neither over nor under attenuated.
Title: Re: High Final Gravities
Post by: tschmidlin on March 01, 2011, 06:02:51 PM
I use Rahr exclusively as my domestic pale malt and I always get the attenuation I expect out of it.  Neither over nor under attenuated.
Yeah, but who was saying they noticed or heard about it affecting their beer and it changed the pH?  It could be that since you use it exclusively you've figured out how to use it to get the beer you want, and if you changed malts to Briess you'd be cursing Briess and their malt :)
Title: Re: High Final Gravities
Post by: denny on March 01, 2011, 06:03:39 PM
I use Rahr exclusively as my domestic pale malt and I always get the attenuation I expect out of it.  Neither over nor under attenuated.
Yeah, but who was saying they noticed or heard about it affecting their beer and it changed the pH?  It could be that since you use it exclusively you've figured out how to use it to get the beer you want, and if you changed malts to Breiss you'd be cursing them and their malt :)

The recipes I use it in were originally formulated with GW pale and I haven't changed anything that I can recall.
Title: Re: High Final Gravities
Post by: bonjour on March 01, 2011, 06:04:22 PM
can you detail your process, and I mean everything, times, temps, recipe, etc.  from mash in to the final in the bottle (or keg).
How/when did you measure your gravities.  Refractometer, hydrometer, both, raw readings, temps.
You cannot have too much detail here.

You have a problem.  We do need more info to help.



Title: Re: High Final Gravities
Post by: bluesman on March 01, 2011, 06:04:40 PM
In addition to a FF test have you considered your fermentation process. What temperature and how consistent are your temps. How are you monitoring the fermentation?  Hydrometer calibration? Secondary?

Just a few things to look at but the FF ferment test will tell us more.

Edit: Fred...our timing on our posts is impeccable.
Title: Re: High Final Gravities
Post by: yaleterrace on March 01, 2011, 06:08:26 PM
My mash pH is always in the 5.0 - 5.3 range, so I think that's okay... not to say I wouldn't rather have a pH meter instead of strips.

I oxygenate my wort pre-pitch in a weird way, but it works.  I have an immersion and a plate chiller, but I use neither these days in favor of a low-energy/no-waste water approach.  Instead, I let the wort cool in the sealed kettle overnight, and transfer vigorously to primary carboys creating a faux krausen of foam to incorporate oxygen.  I know, higher chance of infection this way, but no problems with this process yet.  Always get a strong fermentation, visually active in 6 hours or less.

The Breiss/Rahr thing seems to make little difference, I've had high FGs with both, and in the same realm as one another.

(I'm not trying to shoot down advice, I want more!  I just don't know where this is issue is coming from.)
Title: Re: High Final Gravities
Post by: tschmidlin on March 01, 2011, 06:14:10 PM
Ah, I misunderstood - you said you've brewed 4 with Rahr, and you list 4 at the top, so I thought that was all of them.  Ok, not the malt.  You are vindicated Denny :)

How are you measuring your FG?  Tell me you're using a refractometer :)
Title: Re: High Final Gravities
Post by: maxieboy on March 01, 2011, 06:15:33 PM
Have you always step mashed? Maybe try a single infusion on the next batch to eliminate a variable.
Title: Re: High Final Gravities
Post by: yaleterrace on March 01, 2011, 06:23:44 PM
Okay, here goes:

-I condition malt before milling with a 2 roller mill.
-I dough-in at around 120 degF, and make three rests:
     Protein at 126-129 for 15-20 min
     B-amylase at 146-148 for 20-45 min
     A-amylase at 158-160 for 20-45 min
(saccharification rests total 60-90 min on avg.)
     Mash out at 166 for 5-15 min
-Transfer to lauter tun with false bottom
-Drain 1st runnings (55-60% of original mash H2O avg)
-Batch sparge & drain sparge runnings (105-115% of sparge H2O)
-Recombine 1st and sparge runnings in kettle, bring to boil, skim
-Boil 60-90 min depending; remove hops
-Passive chill in kettle overnight
-Drain to fermenters (aerate) and pitch with starter made with wort from batch

I use pH strips (I know!) to test pH at all 3 rests and mash-out; Use hydrometer and refractometer to monitor gravity during mash, lautering, post-boil, at pitch and during fermentation.  Fermentation temps anywhere from 75 degF in the summer to 65 degF in the winter, (I only brew ales.)  Am I forgetting anything?  At work and don't have my recipe matrix with me...
Title: Re: High Final Gravities
Post by: denny on March 01, 2011, 06:29:37 PM
Although I really doubt it has anything to do with your problem, why the heck are you doing a protein rest with Rahr pale malt?
Title: Re: High Final Gravities
Post by: yaleterrace on March 01, 2011, 06:39:34 PM
Good question.  I prefer a stepped-infusion mash for all of my beers, and I like to keep my process similar for every ale.  I have experimented with unmalted, under-modified and otherwise highly proteinaceous (sp? Ha!) adjuncts, and in the end, hot break is more robust, beer is clearer, yeast seems to be healthily fermenting, etc., as opposed to single-step mashes or skipping the protease attention.  Do I need to?  Probably not, but if I do, it doenst hurt.  I did, however, notice the extensive drain analysis on the Rahr sack compared to Breiss and although I own Technology Brewing and Malting, I do not understand all of the info (on the Rahr tag OR in the book).
Title: Re: High Final Gravities
Post by: redbeerman on March 01, 2011, 08:11:21 PM
One thing that sticks out to me is the sachrification rest.  Worst case would be 20 min beta rest and 45 min alpha rest.  This would make for a very dextrinous wort and more likely give you the high FGs you are seeing in the end.  All in all, for a Saison, for instance, you may want to do a sachrification rest at 145 to 150 F for 90 - 120 minutes to get a more fermentable wort producing a beer that is very dry. JMO   For your other beers I would keep the alpha rest shorter than the beta rest, perhaps in the 30%/70% range.
Title: Re: High Final Gravities
Post by: dcbc on March 02, 2011, 04:59:37 PM
I ran into this on my last two batches after upgrading my kettle from 15 to 20 gallons.  Increased my boil off percentage from 10% to 12% for my most recent batch and hit my numbers precisely.  You didn't mention any equipment changes.  But consider your boil off  rate.
Title: Re: High Final Gravities
Post by: morticaixavier on March 02, 2011, 05:03:27 PM
I ran into this on my last two batches after upgrading my kettle from 15 to 20 gallons.  Increased my boil off percentage from 10% to 12% for my most recent batch and hit my numbers precisely.  You didn't mention any equipment changes.  But consider your boil off  rate.

would this effect the final gravity? wouldn't it just give you lower volume at higher OG?
Title: Re: High Final Gravities
Post by: jeffy on March 02, 2011, 06:12:52 PM

How are you measuring your FG?  Tell me you're using a refractometer :)

I never saw that the OP answered this question.  Measuring the final gravity with a refractometer is about the only thing that accounts for this as far as I can see.
Title: Re: High Final Gravities
Post by: morticaixavier on March 02, 2011, 06:19:59 PM

How are you measuring your FG?  Tell me you're using a refractometer :)

I never saw that the OP answered this question.  Measuring the final gravity with a refractometer is about the only thing that accounts for this as far as I can see.
Use hydrometer and refractometer to monitor gravity during mash, lautering, post-boil, at pitch and during fermentation.

He says he uses both. I feel like if it was just a measurment issue he would be able to taste that. a saison that sweet would just taste wrong and if it doesn't taste wrong than perhaps it is just a measurement issue.
Title: Re: High Final Gravities
Post by: yaleterrace on March 05, 2011, 03:35:58 PM
Hey everybody, back after a few days (just got a chest freezer and did the kegerator conversion routine).  So I tried a quick fermentation test with Safale US-05 and S-04 packets, no results.  I did try pitching a super high gravity yeast (WLP-099) on one of my stuck fermentations in the carboy, and it got right to work.  I also plan on checking all of my thermometers with a friend's that don't reside in my brew room.  Otherwise, I'll be adjusting my mash schedule somewhat, although I am still left puzzled as to why I began having these issues about 10 batches ago, (well after switching to a 20gal Blichmann mash tun).

On a side note about the saison, the grain bill was formulated to get a high FG beer, since I don't like the bitingly dry traditional style.  Instead of getting a dry and thin beer, I was looking to replace dry for hoppy bitterness, and let this offset the residual sweetness.  Toward the end of secondary, I pitched an Abbey Ale yeast starter on the whole shebang to play up the Belgian influence, and the results were great, until I got a much higher FG on the last attempt.  Oh, and the sacc. rests were 45 min @ 147 and 25 min @ 158.  Cheers!
Title: Re: High Final Gravities
Post by: a10t2 on March 05, 2011, 03:46:10 PM
Have you calibrated the hydrometer? I think a beer that finished at >1.030 would be all but undrinkable for most people. Can you buy or borrow a second hydrometer to verify the readings?
Title: Re: High Final Gravities
Post by: tom on March 05, 2011, 04:18:56 PM
Just to double check, you are measuring the final gravity with a hydrometer, not just a refractometer?
Title: Re: High Final Gravities
Post by: oscarvan on March 05, 2011, 04:58:27 PM
Have you calibrated the hydrometer? I think a beer that finished at >1.030 would be all but undrinkable for most people. Can you buy or borrow a second hydrometer to verify the readings?

+1