Why Is My Terminal Gravity So High

[c.bernardoff]

Hey there,

I have recently started BIAB breweing and have been ending up with a high terminal gravity with the last couple of batches. Why??My last batch for example is an APA thats been in the fermenter for 13 days, It started at 1.053, and has stopped at 1.018. The recipe i got says it should come out at 1.008
My strike temp was 71 and mash temp was 67 and dropped to 65 over the hour and mash out at 75. (just checked my thermometer for accuracy in boiling water and it gives a reading about 0.3 degrees lower than what it should be.)
Grain bill as follows:
Golden Promise (Thomas Fawsetts) 2.7
2 row pale (JWM) 3.26
Carapils 0.22
Crystal Grain 0.21
Munich 0.32
Flaked Barley 0.15
Total 6.86Kg
I airated by letting the wort splash into the fermenter from the my cube and every 5L stopped put the lid on and gave the fermenter i nice shake for a minute or 2.
I pitched a pack of US-05 (re hydrated in warmish water), and definately fermented within the recommended temp range.
Im considering bottling now cause ive just tasted it and its not all that sweet.

Any thing obvious that im doing wrong? What are the reasons for a high terminal gravity? and what should i do with the beer - Bottle? add more yeast?

cheerio and look forward to hearing back.

 

[dr K]

1018 is not far far enough out of the ball park to worry to much, could be water.ph lots buts its still just on 65% attenuation, I would be more concerned about the recipe that claimed 84% attenuation !!

K

 

[kelbygreen]

well 67 will give you medium to high body I think it is so doubt it would of ever got to 1008. Was the munich crystal??? As if it was thats a fair bit of crystal not over the top and the flacked barely I never used dunno if it adds much fermentables to the wort.

How long has it been fermenting and at what temps??

 

[browndog]

Two things that come to mind is either your not taking the temp of your mash correctly or your not taking a proper FG reading of your beer. Going by your grain bill and mash temp you should get good attenuation with US05. You have said you checked your thermometer and found it's OK, so how do you check your FG?

cheers

Browndog

 

[yum beer]

By my calculations you should have a FG of around 1016-1017, so your probably on the mark, but I
think you should have started around 1063-1065, so your a fair way off there.

If its been steady for a few days then I say your done.

Give it 5 days to clear up then bottle.

 

[manticle]

Measured with a hydrometer or refractometer?

I'd be wary of 1008 prediction, particularly if your mash temp was actually 67.

How confident are you that all equipment is working properly/accurately?

 

[c.bernardoff]

1018 is not far far enough out of the ball park to worry to much, could be water.ph lots buts its still just on 65% attenuation, I would be more concerned about the recipe that claimed 84% attenuation !!

K

Thats a good point. 84% attenuation was always gonna be a streatch hey.
I didnt know that the water PH can have such an effect. where can i find more info on this? I just use mains water from canberra.

cheers

 

[c.bernardoff]

Two things that come to mind is either your not taking the temp of your mash correctly or your not taking a proper FG reading of your beer. Going by your grain bill and mash temp you should get good attenuation with US05. You have said you checked your thermometer and found it's OK, so how do you check your FG?

cheers

Browndog

Thanks for the reply -
I use a hydrometer and just fill a test tube from the fermenter tap stick in the hydrometer and read from the bottom of the meniscus.

cheers

 

[c.bernardoff]

well 67 will give you medium to high body I think it is so doubt it would of ever got to 1008. Was the munich crystal??? As if it was thats a fair bit of crystal not over the top and the flacked barely I never used dunno if it adds much fermentables to the wort.

How long has it been fermenting and at what temps??

It was munich malt, not crystal.

As for the temp - its been sitting in between 18-21 for 13 days. I dont have great temperature control I just have the fermenter inside on a heated slab.

cheers

 

[Thefatdoghead]

Dont worry about your figures yet. Cold condition after your ferment schedule and keg or bottle for a week or so and taste the beer. If it's good beer then no worries. If it tastes very of from your guidelines etc then go back to your notes and test all your equipment. Maybe don't use dry yeast. Get a stir plate and a smack pack and see what happens.

 

[mje1980]

Hey there,

I have recently started BIAB breweing and have been ending up with a high terminal gravity with the last couple of batches. Why??My last batch for example is an APA thats been in the fermenter for 13 days, It started at 1.053, and has stopped at 1.018. The recipe i got says it should come out at 1.008
My strike temp was 71 and mash temp was 67 and dropped to 65 over the hour and mash out at 75. (just checked my thermometer for accuracy in boiling water and it gives a reading about 0.3 degrees lower than what it should be.)
Grain bill as follows:
Golden Promise (Thomas Fawsetts) 2.7
2 row pale (JWM) 3.26
Carapils 0.22
Crystal Grain 0.21
Munich 0.32
Flaked Barley 0.15
Total 6.86Kg
I airated by letting the wort splash into the fermenter from the my cube and every 5L stopped put the lid on and gave the fermenter i nice shake for a minute or 2.
I pitched a pack of US-05 (re hydrated in warmish water), and definately fermented within the recommended temp range.
Im considering bottling now cause ive just tasted it and its not all that sweet.

Any thing obvious that im doing wrong? What are the reasons for a high terminal gravity? and what should i do with the beer - Bottle? add more yeast?

cheerio and look forward to hearing back.

Give your fermenter a good swirl/shake. You might get a few more points out of it.

 

[goomboogo]

What does your hydrometer read in water at 20c?

 

[gravey]

Give your fermenter a good swirl/shake. You might get a few more points out of it.

I just transfered a Pale Ale into secondary after almost 4 weeks in primary.....it seemed to stall at 1.018, though was still bubbling quite vigorously (once every 30 secs). I was thinking it may have been infected, but the taste and smell is great. In the last week it dropped to 1.010, which was close enough to my target. No idea why it stalled, but perhaps sitting on the washing machine stirred it up a bit and kicked things off to get me to the target

 

[kevin_smevin]

You should be able to get about 75-80% attenuation with US05. That would take you down to 1011-1013 ish. To calculate how much yeast you need per brew you can use this calculation:

750 000 yeast cells (for an ale, twice as much for a lager) x ml wort x degree plato (SG/4) = yeast cell to pitch

So for this recipe assuming you have 20L of wort:

750 000 x 20 000 x 13.25 = 199 billion cells.

Each packet of dry yeast is packed with about 70 billion cells. So you might have better results if you pitched 2 more packets of yeast. Aerating is still important when pitching this much yeast.

You can certainly get away with pitching less yeast but for optimum results you'd need to pitch more.

 

[MarkBastard]

Could just be a case of a few of your measurements being a bit out.

For example maybe your thermometre is reading 2 degrees low, and you didn't stir your mash that well accounting for another 2 degrees. That would make your mash 71 degrees. Plus you have a bit of crystal there, and maybe your hydro is a bit out too.

It's not going to make your beer undrinkable anyway.

 

[Jazzafish]

Thanks for the reply -
I use a hydrometer and just fill a test tube from the fermenter tap stick in the hydrometer and read from the bottom of the meniscus.

cheers

Are you allowing for temperature of sample? The above point of testing/calibrating your hydrometer is also a good point. Get some 20*C distilled water and see what you read. if off 1.000, then this varience needs to be factored in to future readings.

At that gravity, I would look to add more yeast or make a starter (Yes I do starters with dried yeast if I need a higher cell count. Yes I know the risks of contamination from the drying process. No I haven't had it fail as of yet). I think your FG result is ball park, but I believe it will increase a little in this instance.

Something to try is a cooler mash. I have seen a 1*C change significantly affect the attenuation on a commercial scale.

That all said and done, if the beer tastes good and is balanced to your liking... then change nothing next brew and enjoy the fruits of your labour!

 

[///]

I've just had a small trial batch with near the same ingredients go from 1.062 to 1.008 with the same yeast.

A few important points were raised, such as equipment calibration and testing temperatures. Can I ask if you knocked the CO2 out of the sample before trying with the hydrometer. Dissolved CO2 coming out of solution will suspend the hydrometer.

Also the comments on pH (high pH = high TG) and a few on aeration. Eliminating all factors, I'd say a lack of oxygen and nutrients may be the cause. High finishing TG's are a common indicator of not enough o2 for the yeast to do the job.

Scotty

 

[Bribie G]

When I do a <4% ABV mild I start off with a fairly hefty grain bill as if I'm doing an English Special Bitter strength of beer, but I deliberately mash at 70 and end up with a less fermentable wort but packed with flavours. I generally get a FG of up to 1022 using Ringwood or 1469. Last time I didn't hit the 70 and ended up mashing at around 69. It was amazing what effect from just that 1 , I got a FG of around 1018 - still well in the BJCP ballpark.

If you mashed at around 67 and your measurement was out even by a degree it could certainly account for a high FG. I'd have been looking at 65 for your recipe.

 

[c.bernardoff]

When I do a <4% ABV mild I start off with a fairly hefty grain bill as if I'm doing an English Special Bitter strength of beer, but I deliberately mash at 70 and end up with a less fermentable wort but packed with flavours. I generally get a FG of up to 1022 using Ringwood or 1469. Last time I didn't hit the 70 and ended up mashing at around 69. It was amazing what effect from just that 1 , I got a FG of around 1018 - still well in the BJCP ballpark.

If you mashed at around 67 and your measurement was out even by a degree it could certainly account for a high FG. I'd have been looking at 65 for your recipe.

Cool - Im gonna end up with a really tasty 4% beer, Thats great Ill just drink more in each sitting.

Yeah, Im pretty convinced I've been mashing too high. Ive ended up with a higher than expected final gravity on the last three brews each time using the same temps. Next time Ill drop 1 degree and eliminate 1 possibility.

cheers

 

[JDW81]

I've just had a small trial batch with near the same ingredients go from 1.062 to 1.008 with the same yeast.

A few important points were raised, such as equipment calibration and testing temperatures. Can I ask if you knocked the CO2 out of the sample before trying with the hydrometer. Dissolved CO2 coming out of solution will suspend the hydrometer.


I had never thought of that, but it makes perfect sense. How do you knock the CO2 out to prevent it from suspending the hydrometer? Is tapping the measuring tube on the bench sufficient?

I'm struggling with this at the moment as well. My ESB FG is stuck at approx 1021 after two weeks and I was putting it down to a mash temp 2 degrees above what I intended due to an I.D.I.O.T error in beersmith. But it sounds like it might be a few factors. I'll check the calibration of my hydrometer, learn to use beersmith better and try and eliminate some suspended CO2 from test samples.

JD