Consistent low final gravity, need a little advise please

Shamby

Shamby

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I have been brewing for some time now and I have a hard time hitting my final gravity numbers. I'm always way to low like by 10 points. I mash in at 152 and mash out at around 168. I usually can hit my Original gravity before boil but never my final gravity. I use imperial liquid yeast always with a starter and ferment at 68. The beers taste fine but always on the dry side, any ideas on what I could be doing wrong? Below is a common recipe I use. I hit my original gravity but my final was 1.006. I use Spikes 3 kettle HERMS for my equipment. Thanks


STATS:
Original Gravity: 1.062
Final Gravity: 1.014
ABV (standard): 6.3%
IBU (tinseth): 34.91
SRM (morey): 5.87
Mash pH: 0

FERMENTABLES:
11 lb - Standard 2-Row (88%)
1 lb - American - Caramel Malt - 20L (8%)
0.5 lb - American - Carapils Malt (4%)

HOPS:
1 oz - Cascade, Type: Pellet, AA: 6, Use: Mash, IBU: 2.13
1 oz - Cascade, Type: Pellet, AA: 6, Use: Boil for 15 min, IBU: 5.31
1 oz - Cascade, Type: Pellet, AA: 6, Use: Whirlpool for 0 min at °F, IBU: 4.09
1 oz - Chinook, Type: Pellet, AA: 13.1, Use: Boil for 60 min, IBU: 23.37
1 oz - Cascade, Type: Pellet, AA: 6, Use: Dry Hop for 0 days
1 oz - Chinook, Type: Pellet, AA: 13.1, Use: Dry Hop for 0 days
 
A few possibilities that come to mind:

1. Your thermometer is off and your mash temp was actually lower
2. Your hydrometer is off, giving you a low reading.
3. Did you previously brew using a diastatic yeast, such as a saison? If some of those yeast cells remain, it could attenuate lower than you would expect.

BTW, welcome to the forum!
 
1. What particular yeast are you using?
2. What temperature are you fermenting at at? You say 68, but does the wort stay at that temp for the entire time?
3. How long are you mashing for?

Some yeasts will attenuate far more than others and high fermentation temps usually lead to quick fermentations and over attenuation. And a long mash *might* make a more fermentable beer.

Apologies, because I'm sure you are aware of this, but I had to ask.

In your example, OG = 1.062, FG = 1.006, that’s 90% attenuation. Pretty high for most yeasts, but not out of reach for some.
 
Thanks for the quick replies.
I'm hoping that the easy answer is that my mash temperatures are to low but I have a cheap thermometer that I check with my main temperature and they are within 2 degrees from each other. I've ordered a more accurate thermometer for a better comparison. I use tilt hydrometers in my fermenters and they are generally accurate

As for yeast I use imperial liquid yeast always with a starter and I hold the 68 with a glycol chiller. You have a good point on quick fermentation, my beers take no more then a 7 to 10 days to fermit. Very fast
 
Shamby said:
Thanks for the quick replies.
I'm hoping that the easy answer is that my mash temperatures are to low but I have a cheap thermometer that I check with my main temperature and they are within 2 degrees from each other. I've ordered a more accurate thermometer for a better comparison. I use tilt hydrometers in my fermenters and they are generally accurate

As for yeast I use imperial liquid yeast always with a starter and I hold the 68 with a glycol chiller. You have a good point on quick fermentation, my beers take no more then a 7 to 10 days to fermit. Very fast
Click to expand...
Unless I’m misunderstanding, Imperial is just a brand name. They make many different yeasts.
https://www.imperialyeast.com/organic-yeast-strains/
 
If you are getting 90% with that yeast then something isn’t right. A couple of degrees in mash temp isn’t going to do it, in my opinion.

Read @MaxStout ‘s reply above. Especially #2 and 3. Either measurement error or maybe something more nefarious, like remnants from a previous brew or an infection.

First thing I would do is double check your final gravities on your Tilt vs a hydrometer to make sure they are the same, and then give your equipment a good, thorough cleaning.

Good luck.
 
Will do. I mash for 1 hour always. After every brew day I clean everything with PBW and starsan along with my fermenters . I have to agree it does not add up. I'll also check my tilt vs. a hydrometer. Thanks again.
 
Shamby said:
I'm using my tilt for final gravity.
Click to expand...

A Tilt is a great device to monitor the progress of fermentation and give you an idea of when it's done. But don't rely on it for accurate FG readings, as it is better suited for tracking changes. I have heard some Tilt owners say that it can become encrusted with debris while floating in the beer, affecting its buoyancy and thus, gravity readings.

Take a sample and use a regular hydrometer.
 
Been using tilts for 3 years. Don't trust them for ultra accurate results. Great for trends, but tend to be a little flakey. Have had mine be up to 5pts off. Not the end of the world.

I agree though, 90% would be highly unlikely unless you have some lacto or brett in there. Pbw and star San won't kill it either. I would run some boiling water in your fermentors and soak in iodofur for 30 minutes. See if that doesn't slow it down
 
A bunch of questions from me to try and work through the diastaticus idea. Any chance of an image of the tilt data? Over attenuation due to diastaticus is pretty recognisable. After the main fermentation is done the gravity drops by one point every 1.5 to 3 days and depending on the mash it can take weeks to stop. What's your trigger for deciding the fermentation is finished?

How do you package your beer? If you bottle do you have a lot of highly carbonated beers?
 
Here is the tilt info
12/16/2022 15:59:23 1.005
12/15/2022 6:44:43 1.005
12/14/2022 16:26:44 1.011
12/14/2022 6:44:10 1.012
12/13/2022 20:41:27 1.015
12/13/2022 15:48:33 1.016
12/13/2022 12:43:50 1.019
12/13/2022 6:44:39 1.022
12/12/2022 18:56:42 1.029
12/12/2022 17:12:09 1.026
12/12/2022 16:56:27 1.026
12/12/2022 6:40:07 1.031
12/11/2022 17:48:24 1.041
12/11/2022 8:00:28 1.050
12/10/2022 17:56:22 1.056
12/10/2022 17:15:07 1.055
12/10/2022 16:51:12 1.061

When I don't see a gravity change for a day or two I consider it done. I keg my beers. I've ordered some Iodophor and plan on boiling and sanitizing everything good over the holiday weekend. Thanks again
 
Shamby said:
Here is the tilt info
12/16/2022 15:59:23 1.005
12/15/2022 6:44:43 1.005
12/14/2022 16:26:44 1.011
12/14/2022 6:44:10 1.012
12/13/2022 20:41:27 1.015
12/13/2022 15:48:33 1.016
12/13/2022 12:43:50 1.019
12/13/2022 6:44:39 1.022
12/12/2022 18:56:42 1.029
12/12/2022 17:12:09 1.026
12/12/2022 16:56:27 1.026
12/12/2022 6:40:07 1.031
12/11/2022 17:48:24 1.041
12/11/2022 8:00:28 1.050
12/10/2022 17:56:22 1.056
12/10/2022 17:15:07 1.055
12/10/2022 16:51:12 1.061

When I don't see a gravity change for a day or two I consider it done. I keg my beers. I've ordered some Iodophor and plan on boiling and sanitizing everything good over the holiday weekend. Thanks again
Click to expand...
Not questioning that it is done, the tilt does a good job, just a matter of if it truly 1.005 or is it 1.010?
 
Classic precision vs. accuracy situation. A couple consistent FG readings, but might not be accurate. Seems odd that it would drop 6 points in one day (12/14-12/15), after the previous several days showed 1-3 point daily drops. I'm thinking those last 2 are outliers, perhaps due to something affecting the buoyancy.
 
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