Help with ongoing high finishing gravity

[Killer Brew]

As the title suggests I am time and time again having issues with my FG finishing at 1015 or above. In fact the only brews I have been able to get down to below this so far have been using Belle Saison yeast which is known to be very aggressive. This is leaving me with a sweeter tasting beer than I desire. The below recipe is an example with it now sitting at 1022 in the fermenter after 10 days.

Title: Critters IPA

Brew Method: Partial Mash
Style Name: American IPA
Boil Time: 60 min
Batch Size: 21 liters (fermentor volume)
Boil Size: 11 liters
Boil Gravity: 1.144
Efficiency: 85% (brew house)

STATS:
Original Gravity: 1.076
Final Gravity: 1.014
ABV (standard): 8.11%
IBU (tinseth): 35.57
SRM (morey): 10.56

FERMENTABLES:
1 kg - Dry Malt Extract - Light (18.2%)
1.5 kg - Liquid Malt Extract - Munich (27.3%)
2 kg - United Kingdom - Maris Otter Pale (36.4%)
0.6 kg - American - Rye (10.9%)
0.4 kg - United Kingdom - Crystal 45L (7.3%)

HOPS:
25 g - Fuggles, Type: Pellet, AA: 4.5, Use: Boil for 60 min, IBU: 5.83
25 g - Amarillo, Type: Pellet, AA: 8.6, Use: Boil for 30 min, IBU: 8.56
25 g - Sorachi Ace, Type: Pellet, AA: 11.1, Use: Boil for 30 min, IBU: 11.05
20 g - Simcoe, Type: Pellet, AA: 12.7, Use: Boil for 30 min, IBU: 10.12
10 g - Amarillo, Type: Pellet, AA: 8.6, Use: Boil for 0 min
20 g - Citra, Type: Pellet, AA: 11, Use: Boil for 0 min
10 g - Sorachi Ace, Type: Pellet, AA: 11.1, Use: Boil for 0 min

MASH GUIDELINES:
1) Decoction, Temp: 67 C, Time: 60 min, Amount: 10 L

YEAST:
Fermentis / Safale - American Ale Yeast US-05
Starter: No
Form: Dry
Attenuation (avg): 81%
Flocculation: Medium
Optimum Temp: 12.22 - 25 C
Fermentation Temp: 16 C

It isn't only US-05 I have the problem with as I had the same thing with dry Nottingham and a liquid British Ale yeast. The dry yeasts I rehydrate for a few hours and always pitch at around the fermenting temp after doing my best to aerate by pouring into the fermenter from a height and splashing it around with the spoon. Have tried giving a gentle stir, increasing temp toward the end but no result. Looking for ideas from those more experienced (eg. do I remove Crystal from my recipes, do I need to aerate better, should I repitch fresh yeast and what type). Cheers!

 

[wide eyed and legless]

How much yeast did you pitch?

 

[TheWiggman]

The things I can see that will influence the FG -

• OG (if it's very high your SG will be high too)
• Yeast quantity and health
• Type of yeast
• Dissolved oxygen in the wort
• Content of non-fermentable sugars primarily from -
  High mash temp on grains
• Excessive quantity of specialty malts

[*]Nutrients in the wort
I'll assume your hydrometer is reading correctly. If you're not sure, double-check as you could be chasing your tail if you don't.
You have a fair portion of malted grain in there which you say you're mashing at 67°C. For a drier finish, drop your temp down to 63°C or thereabouts to increase the proportion of alpha amylase in the wort.
Reducing the amount of crystal will help but not by much give that quantity.
With an OG of 1.076 I think and FG of 1.022 isn't all that bad especially considering the mash temp for 1/3 of your fermentables. You would want two sachets of US-05 for that brew though.

 

[pat_00]

In a beer that strong it's borderline to be pitching 2 packs.

Are you aerating the wort? what about yeast nutrient?

 

[Killer Brew]

How much yeast did you pitch?

Pitched just the 1 pack of US-05 which I rehydrated for approx 3 hours.

 

[Killer Brew]

The things I can see that will influence the FG -

• OG (if it's very high your SG will be high too)
• Yeast quantity and health
• Type of yeast
• Dissolved oxygen in the wort
• Content of non-fermentable sugars primarily from -
  High mash temp on grains
• Excessive quantity of specialty malts

[*]Nutrients in the wort
I'll assume your hydrometer is reading correctly. If you're not sure, double-check as you could be chasing your tail if you don't.
You have a fair portion of malted grain in there which you say you're mashing at 67°C. For a drier finish, drop your temp down to 63°C or thereabouts to increase the proportion of alpha amylase in the wort.
Reducing the amount of crystal will help but not by much give that quantity.
With an OG of 1.076 I think and FG of 1.022 isn't all that bad especially considering the mash temp for 1/3 of your fermentables. You would want two sachets of US-05 for that brew though.

Thanks. Have checked the hydrometer and is ok. Interesting on the lower mash temp and additional yeast pack, will try that. Also have never tried adding yeast nutrients. After 10 days is it too late to pitch a second pack of yeast or add nutrients?

I do aerate by pouring into the fermenter from above shoulder height which gets plenty of froth. I then thrash it with a spoon. Do you think I need to go a step further and get a slotted paddle or I have read about others using fish tank aerators?

 

[wide eyed and legless]

I reckon that is where your problem is, not enough yeast you are brewing a big beer as pat said you would be better off putting in the 2 pkts.

 

[The Holy Ale]

I agree. I would definitely go with two packs. For anything over 1.060 it's a good idea. Also aerating a bit more could help, shake the shit out of the fermenter for as long as you can be bothered.

Also rehydrating for 3 hours seems excessive to me. Not sure if it would have a detrimental effect but 30mins should be more than enough time.

Do you have the same issue with lower gravity beers? What temperature are you fermenting at?

 

[manticle]

Massive gravity, 1 pack, lots of malt extract, high mash temp, good portion of crystal malt - you've done well to get to 1015 to be honest.
Add enough fresh stuff and rehydrate according to manufacturer's instructions or not at all.

 

[Killer Brew]

I agree. I would definitely go with two packs. For anything over 1.060 it's a good idea. Also aerating a bit more could help, shake the shit out of the fermenter for as long as you can be bothered.

Also rehydrating for 3 hours seems excessive to me. Not sure if it would have a detrimental effect but 30mins should be more than enough time.

Do you have the same issue with lower gravity beers? What temperature are you fermenting at?

Have had the same issue with beers with SG of 1050 and under also. Ferment between 16 - 18 degrees. Will pitch another pack of US-05 dry tonight.

 

[Killer Brew]

Massive gravity, 1 pack, lots of malt extract, high mash temp, good portion of crystal malt - you've done well to get to 1015 to be honest.
Add enough fresh stuff and rehydrate according to manufacturer's instructions or not at all.

Actually this one is still at 1022. Interesting on the malt extract, are there unfermentables there? Mash temp has been around 67 so will try 63 next brew.

 

[manticle]

In my experience extract brews often finish higher than ag or kit. Something to do with Free Amino Nitrogen levels from memory but it's all a bit vague.

 

[The Holy Ale]

I'm not sure of the make up of it but extract tends to not attenuate as well as all grain especially when mash temp is kept low.

Even at 1050 there is a case to pitch more. There are calculators online that can be helpful.

Also if you start fermenting at 18C and it drops to 16C after a day or so it could cause the yeast to stall or become sluggish at least. Try to keep temps as stable as possible for at least the first 3-4 days for an ale then if anything raise them higher after that to help them finish off.

 

[Killer Brew]

Thanks everyone. A few things there for me to work on.

 

[NickyJ]

I've always found that munich liquid malt extract to give a high finishing gravity. I assume that's the briess brand one?

Is your fermentation temp sensor reliable? Could you be dropping below 16 degrees?

 

[Kingy]

Id mash at 64-65 degrees, definately use 2 packs of yeast and ferment at 17degrees. I think your underpich is the main thing in getting your fg down.

 

[MHB]

If you look at what the yeast has done, taking the wort from 1075 to 1022 that's a change of 53 points or about 71% apparent. I wouldn't be surprised it that's all US05 will do in a 1075 wort (normally about 75%) but the higher the OG the lower the attenuation for the same yeast pitch.
Ideally you would be pitching about 4 packets or making a big starter, or choosing a more attenuateive yeast (try SO4) or a bit of both, bigger pitch and more attenuateive.
Another trick to get better attenuation is to reduce the OG and add some of the fermentables later in the ferment but if you want to make good high alcohol beer there really is nothing other than much bigger yeast pitches to get everything working well.
Mark

 

[kevo]

This is handy...

http://www.mrmalty.com/calc/calc.html

I used to sub out 10% of the dry extract and replace with plain sugar to help things dry out - especially in something like the beer you've described above.

Kev

edit ....and ... didn't see this mentioned above... once you're through the first few days of active fermentation, what's happening with the temperature?

 

[Killer Brew]

This is handy...

http://www.mrmalty.com/calc/calc.html

I used to sub out 10% of the dry extract and replace with plain sugar to help things dry out - especially in something like the beer you've described above.

Kev

edit ....and ... didn't see this mentioned above... once you're through the first few days of active fermentation, what's happening with the temperature?

Temp wise I have just been setting the fridgemate at 16 degrees and leaving it until at FG then cold crashing. This time around I have removed it from the fridge after 10 days, given it a stir and it is now sitting in my brew room which holds a fairly constant temp of around 18 degrees.

 

[Killer Brew]

I've always found that munich liquid malt extract to give a high finishing gravity. I assume that's the briess brand one?

Is your fermentation temp sensor reliable? Could you be dropping below 16 degrees?

Yes it was the Briess one, first time I have used it. I use a fridgemate and have calibrated it in a glass of water against another thermometer, seems spot on.