Author Topic: High FG  (Read 709 times)

Offline sbuller38

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High FG
« on: January 12, 2014, 07:53:14 PM »
Here's a new one for me. I recently checked the gravity readings of my beer before I kegged it and it gained almost 2 hole percentage points in ABV... it went from about a 4% isn ABV to a 6% ABV. Any thoughts on why this happens?

Offline Jeff M

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Re: High FG
« Reply #1 on: January 12, 2014, 07:57:45 PM »
how are you determining the ABV in your beers?  List recipe, OG and FG
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Offline majorvices

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Re: High FG
« Reply #2 on: January 13, 2014, 07:11:58 AM »
Here's a new one for me. I recently checked the gravity readings of my beer before I kegged it and it gained almost 2 hole percentage points in ABV... it went from about a 4% isn ABV to a 6% ABV. Any thoughts on why this happens?

If it was really doing that the beer would be incredibly over carbonated and the keg very over pressurized. Is that happening?

Are you checking the beer with a calibrated hydrometer? Are you using a hydrometer and not a refractometer? If using a refractometer are you making the post fermentation calculations?

I highly doubt that your beer fermented out 2 more percentage points. It must be a problem with the way you are taking your reading.
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Offline sbuller38

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Re: High FG
« Reply #3 on: January 13, 2014, 07:54:11 AM »

Here's a new one for me. I recently checked the gravity readings of my beer before I kegged it and it gained almost 2 hole percentage points in ABV... it went from about a 4% isn ABV to a 6% ABV. Any thoughts on why this happens?

Opps, I checked my sheet again, and it was supposed to be 5% ABV not 4. So it went up almost 1.14% from last nights math problem. But today when I tried it with the long equation doing (OG-FG)131, it equaled
 5.74%

.75 lbs Caramel/Crystal 80L
.75 Special B
.75 Special Roast
.75 Victory
.80 Honey
.85 Chocolate
6.25 2 row

I have been using a hydrometer for both my OG and FG. We haven't purchased a refractometer yet because we don't have the money for it right now. I also tend to use BeerSmith to help figure out estimated ABVs and the works

OG was supposed to be about 1.054, and I hit that, but my FG was supposed to be 1.016 and I hit a 1.010.

After last nights attempt with a quick ABC calculator, I just tried the long form with the equation (OG - FG)131 and I got 5.74%.

As for the Keg question, those readings occurred before it was even kegged. I haven't had any keg issues.

I'm using a calibrated hydrometer that reads at 60 degrees F. I did do equations but I think the calculator on the internet was the problem. I'm sticking to the long hand method, seems more accurate.

Offline majorvices

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Re: High FG
« Reply #4 on: January 13, 2014, 08:12:40 AM »
I guess I'm a little confused by your question. Sounds like you are saying that the beer continued to ferment at some point in time after which you thought it was done(?), which is very possible especially if you racked it early.

If you had nearly a pound of honey in I would not expect a FG as high as 1.016. OTOH you have a lot of crystal malts going on there so it's hard to say.

As long as it tastes fine I wouldn't worry about it. The yeasts are going to continue to ferment until they reach their attenuation point. It might be possible you have some sort of infection that is driving down the FG even further, but again, as long as it tastes alright that probably isn't a problem.
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Offline sbuller38

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Re: High FG
« Reply #5 on: January 13, 2014, 08:22:18 AM »
I guess I'm a little confused by your question. Sounds like you are saying that the beer continued to ferment at some point in time after which you thought it was done(?), which is very possible especially if you racked it early.

If you had nearly a pound of honey in I would not expect a FG as high as 1.016. OTOH you have a lot of crystal malts going on there so it's hard to say.

As long as it tastes fine I wouldn't worry about it. The yeasts are going to continue to ferment until they reach their attenuation point. It might be possible you have some sort of infection that is driving down the FG even further, but again, as long as it tastes alright that probably isn't a problem.

That's the only thing that I could think of. I just received the official copy of my sheet via text message and I did the equation again... it came out to 6.157% EST ABV., with temperature adjustments. I guess I was just shocked at the readings considering I just racked it after 2 weeks, but I guess those yeasties were still hungry.

Either way, it tastes fine, a nice chocolate feel to it, and I really enjoyed it. Guess I was shocked because I had a Belgian Pale Ale Fermenting right next to it too, and that one came out perfect (in regards to readings).

Thanks for the thoughts.   

Offline morticaixavier

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Re: High FG
« Reply #6 on: January 13, 2014, 08:44:14 AM »
I think the thing to remember is that, especially with all grain brewing, the estimated FG is just that, an estimate. you can't use it for anything except to get a general idea about what the FG might be.

If you mashed at anything below say 155 I would not expect a 1.016 finishing gravity with that recipe. remember the beer makes the schedule not the brewer.

If after two weeks you take a gravity reading and then take another one 3-5 days later and they are the same then it is probably done. Otherwise you just don't know.

also 'Official copy of me sheet', are you sending samples for analysis?
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Offline majorvices

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Re: High FG
« Reply #7 on: January 13, 2014, 08:49:41 AM »
Yeah, I pretty much ignore the FG estimates the computer programs tell me. It's always high.
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Re: High FG
« Reply #8 on: January 13, 2014, 08:57:26 AM »
.....along with most stated yeast attenuation rates and temp ranges.
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Offline sbuller38

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Re: High FG
« Reply #9 on: January 13, 2014, 09:34:04 AM »
also 'Official copy of me sheet', are you sending samples for analysis?

No, I print out a sheet for each brew I do, so I can keep track of all gravity readings. I travel back and forth between NYC and Lancaster, PA to brew. It's not ideal but sometimes I have to get my g.f. to send me pics of the sheets to go back over some recipes or gravity readings to see what's going on with the beer.

Offline sbuller38

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Re: High FG
« Reply #10 on: January 13, 2014, 09:36:18 AM »
Yeah, I pretty much ignore the FG estimates the computer programs tell me. It's always high.
- Agreed, I think I will start figuring out a recipe by hand as opposed to the program. I think I'm comfortable enough after 7 batches that I can start developing the recipe by hand instead of using BeerSmith.

.....along with most stated yeast attenuation rates and temp ranges.
- Yha, Yeast... always seems to be a little different

Offline denny

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Re: High FG
« Reply #11 on: January 13, 2014, 09:50:21 AM »
Yeah, I pretty much ignore the FG estimates the computer programs tell me. It's always high.
- Agreed, I think I will start figuring out a recipe by hand as opposed to the program. I think I'm comfortable enough after 7 batches that I can start developing the recipe by hand instead of using BeerSmith.

.....along with most stated yeast attenuation rates and temp ranges.
- Yha, Yeast... always seems to be a little different

Software is great for creating recipes.  I've used it for every one of the 450 batches I've brewed.  What people are saying, though, is that when the software predicts an FG, it really has no accurate way of doing that.  You can just ignore that particular prediction.
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Offline morticaixavier

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Re: High FG
« Reply #12 on: January 13, 2014, 10:12:33 AM »
Yeah, I pretty much ignore the FG estimates the computer programs tell me. It's always high.
- Agreed, I think I will start figuring out a recipe by hand as opposed to the program. I think I'm comfortable enough after 7 batches that I can start developing the recipe by hand instead of using BeerSmith.

.....along with most stated yeast attenuation rates and temp ranges.
- Yha, Yeast... always seems to be a little different

Software is great for creating recipes.  I've used it for every one of the 450 batches I've brewed.  What people are saying, though, is that when the software predicts an FG, it really has no accurate way of doing that.  You can just ignore that particular prediction.

+1 I love using beersmith for building recipes and since my 'brewery' is just steps away from my computer I use it on brew day as well just to remind myself what I'm doing. I take notes on each reading and sample I take and record actual measurments along side the estimates it gives me. The estimates are never correct and as Major says, at least with FG, almost always high.

If you want to do it by hand that's fine but you still won't know what the final gravity is going to be until you've brewed the recipe a few times.


**EDITED TO CORRECTLY ATTRIBUTE IDEAS **
« Last Edit: January 13, 2014, 10:43:58 AM by morticaixavier »
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Offline goschman

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Re: High FG
« Reply #13 on: January 13, 2014, 10:40:56 AM »
Agree with the above posts.

I usually get higer attenuation than Beersmith would predict. I keep a spreadsheet of my own to see what attenuations I get on my system for different yeast strains. When using a new yeast you kind of just have to try it since you don't have anything to base it's performance on. In my most recent batch, I used a new yeast that was rated for 72-78% attenuation. I got 85%...

Offline sbuller38

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Re: High FG
« Reply #14 on: January 14, 2014, 08:33:58 AM »
Makes sense guys, thanks. Definitely a lot more mental stuff to add into when I'm brewing my next batch.

Mucho gracias