Can somebody help me with a high final gravity. In search of solutions or cause of problems.

[brewbuddynick]

Greetings fellow brewers! About three weeks ago, I embarked on my tenth all-grain beer brewing adventure, crafting a delightful amber ale. However, it seems the fermentation process has been a bit sluggish, concluding a week ago with a final gravity of 1.020 – a tad higher than the anticipated 1.012.

Admittedly, I realized I may have under-pitched the yeast a bit too late in the game. Despite this hiccup, I soldiered on, hoping for a miraculous gravity drop. Noteworthy, my hydrometer was calibrated in distilled water.

Fermentation took place at 19°C, with a slight temperature boost to 20.5°C in the last week in an attempt to rev up the process.

Now, I find myself pondering the use of my remaining 2 packs of S-04 – is a repitch in order, or do you seasoned brewers have alternative pearls of wisdom to share?

Your insights are much appreciated!

For those curious minds, here's the breakdown of the recipe:

• Original Gravity (OG): 1.060
• Measured Final Gravity (FG): 1.020
• Expected FG: 1.012

Grains:

• 3.45 kg (75.2%) Swaen Pilsner — Grain — 3.7 EBC
• 780 g (17%) Weyermann Carared — Grain — 47.5 EBC
• 180 g (3.9%) Swaen Goldswaen Brown — Grain — 220 EBC
• 180 g (3.9%) Weyermann Melanoidin — Grain — 59 EBC

Hops:

• 14.7 g (14 IBU) Cascade 6.8% — Boil — 60 min
• 11.6 g (9 IBU) Centennial 9.1% — Boil — 20 min
• 11.6 g (5 IBU) Cascade 6.8% — Boil — 15 min
• 23.2 g (5 IBU) Amarillo 7.4% — Boil — 5 min
• 11.6 g (3 IBU) Centennial 9.1% — Boil — 5 min

Mash:

• Temperature — 66.7°C — 60 min
• Mash out — 75.6°C — 10 min

Yeast:

• 1 pack — Fermentis US-05 Safale American (rehydrated)

Looking forward to your brewing wisdom and advice! Cheers!

 

[VikeMan]

Given your recipe and mash specs, I'd predict your FG to end up around 1.015. (I'm assuming your actual OG was 1.060.) How sure are you of your mash temperature, and how did you measure it? And was your thermometer(s) calibrated? Also, are you by any chance using a recirculating mash system?

 

[brewbuddynick]

Given your recipe and mash specs, I'd predict your FG to end up around 1.015. (I'm assuming your acual OG was 1.060.) How sure are you of your mash temperature, and how did you measure it? And was your thermometer(s) calibrated? Also, are you by any chance using a recirculating mash system?

I'm not 100% sure about the temperature. I brew on the grainfather g30 and expected it to be correct from the box

 

[Stikius]

With G30 (Brewfather preset efficiency values) I calculated the grain bill to get OG 1.060 with 14.8 liters in fermenter. With the mash temps mentioned it should also result in 1.012 FG. I suspect either mash temperature need to be calibrated if you only reached 1.020 in 2 weeks, or temperature swings during fermentation could have confused the yeast. At least those two would be the two first things I would investigate since they are most likely the easiest ones to verify.

 

[brewbuddynick]

is there any

With G30 (Brewfather preset efficiency values) I calculated the grain bill to get OG 1.060 with 14.8 liters in fermenter. With the mash temps mentioned it should also result in 1.012 FG. I suspect either mash temperature need to be calibrated if you only reached 1.020 in 2 weeks, or temperature swings during fermentation could have confused the yeast. At least those two would be the two first things I would investigate since they are most likely the easiest ones to verify.

is there anyway to fix this now, add more yeast or just accept it?

 

[Stikius]

In case the mash temperature was too high there's not much to do really. You could add some sugar to get ABV up, but there would still be unfermentable sugars left. Or add a yeast that can handle those sugars.
I would probably just try it, and if it tastes ok you can happily drink it while figuring out what went wrong before next brew. I honestly wouldn't try to fix a beer if I just miss a few points. If it tastes crappy just pour it out and start over again more or less. But then again, I'm not the worrying kind. Sometimes my hommus gets to thick and not at all as fluffy as I want it, but I just eat it anyway...

There are most likely people here with much more insight and experience on how to fix a beer though. I wouldn't bother, but rather take notes and change process/procedure. Every time something goes wrong there's an opportunity to learn

 

[Bassman2003]

I agree with the posts above. 1st place to look is your temperature measurements. If the mash actually took place at a higher temperature then you would end up with less fermentable sugars and a higher final gravity. Mashing really sets the tone for how much attenuation you can expect. If you mash for some time at lower temps (beta rest 62-65C) the wort composition will contain more for the yeast to work with.

Another angle is yeast cell count. 1.060 is pushing it for one pack of dry yeast. I know many probably use one pack but you will have a stronger ferment if you use two packs. So if you brew this beer again, try using two packs of US05 and it will probably power through.

 

[mac_1103]

FWIW, I direct pitch dry yeast and have never had an issue getting from an OG of up to 1.066 down to a FG < 1.015 with one pack of US-05 or S-04. It's within Fermentis' recommendations even if it's an underpitch according to many (most?) calculators. So my personal opinion is that OP's problem is with his mash thermomter. But if he's brewed nine other batches on the same equipment without issues that argues against my opinion.

I usually will use two packs for anything much over 1.070, but I've done a couple of high gravity stouts with lots of unfermentables with a single pack of S-04 and reached the expected FG within four weeks. I don't have a tilt or anything so I couldn't tell you what my curves look like. For all I know they could be stopping cold after two weeks and starting again after three. Seems unlikely though.

 

[Stikius]

I also had some thoughtd about that. Is is the tent batch on the G30 or is it the first batch on tat equipment? "Tenth all-grain beer brewing adventure" could be just about anything. Anyway, assuming the OG of 1.060 was the expected OG this was a 14.8 liter (3.25 gallon) batch. I wouldn't pitch 2 packs yeast into that.

I suspect this has to do with either mashing or fermenting temps. Could of course be bad water or a whole lot of other things as well but I would investigate G30 thermometer first of all. All you need is a bit of water and a thermometer to verify it is correct. An FG of 1.020 however, would probably require a mashint temperature a few degrees over 70°C which would be way off from 66.7°C. I wouldn't be super surprised if it was 1 or even 2 degrees off, but 5..?

 

[Bassman2003]

Sorry, I did not realize this was for a 3.25 gallon batch. I guess you worked backwards from the grain bill amounts and the OG. Yes, 2 packs for 3.25 gallons is probably not needed.

 

[Bobby_M]

21% crystal malts at that mash temp, I'm not baffled. I suspect perhaps your controller probe is slightly out of calibration reading low maybe a degree or two.