OG 1.072, FG 1.020 = Stuck Fermentation?

[wstcstnative]

I know I messed this up a little bit. I used one smack pack of old yeast and no starter. I also ended up with a higher OG than expected (1.065 target). The target final gravity was 1.012...does this mean I have a stuck sparge? I'm brewing a dry-hopped double IPA and i'm 2 weeks in primary so far. Is there anything I can do to get this down to target or is it pretty much over for this beer?

 

[dstockwell]

You may be able to rouse the yeast and it might go lower, but hard to say without knowing the recipe, and mash temp.

 

[Morrey]

1.020 may be a shade over your target gravity but should be a nice beer with a great mouthfeel. I personally wouldn't try to do something like add more yeast for fear of drying it out beyond enjoyable. I actually like for my double IPAs to be no less than 1.015 for the richness. Some may disagree with my FG ideas, but I'm sure it will be a good drinking ale.

**A stuck sparge means wort wont drain thru your grain bed in a multi vessel AG system. You may be thinking stuck or stalled fermentation.

If you can raise the ferm temp a degree or two that may rouse it too.

 

[rmyurick]

I think for most yeast varieties that's pretty good. (72% apparent dof) Unless there was some sugar in the recipe.

 

[wstcstnative]

no sugar. mash temp was 155F. recipe was a Bell's Two Hearted IPA clone...LBHS didn't have exact matches for my recipe, so some substitutions were made in grain bill. yeast was Wyeast Pacman, 1 smack pack. 5 gal batch size.

 

[Morrey]

I think you've done a good job^^^. Enjoy!!

 

[wstcstnative]

1.020 may be a shade over your target gravity but should be a nice beer with a great mouthfeel. I personally wouldn't try to do something like add more yeast for fear of drying it out beyond enjoyable. I actually like for my double IPAs to be no less than 1.015 for the richness. Some may disagree with my FG ideas, but I'm sure it will be a good drinking ale.

**A stuck sparge means wort wont drain thru your grain bed in a multi vessel AG system. You may be thinking stuck or stalled fermentation.

If you can raise the ferm temp a degree or two that may rouse it too.

you're right...stalled fermentation is what i meant

 

[wstcstnative]

I think you've done a good job^^^. Enjoy!!

thank you. i've been quite impressed with my igloo cooler. it holds temps pretty well. i usually only lose 1 or 2 degrees at the most.

 

[kh54s10]

Pacman attenuation 72-78% 155 is high for an IPA. I would have mashed that about 150 so I am not surprised at the FG. I bet it is done. The under-pitch may have lead to some off flavors, they should be masked by the hops, but I think you got all you are going to get.

Look into making starters whenever you use liquid yeast.

Added: There should be nothing wrong with the beer - maybe a tad sweeter than it should have been.

Also: assuming you mean a stuck fermentation and not a stuck sparge......

 

[wstcstnative]

Pacman attenuation 72-78% 155 is high for an IPA. I would have mashed that about 150 so I am not surprised at the FG. I bet it is done. The under-pitch may have lead to some off flavors, they should be masked by the hops, but I think you got all you are going to get.

Look into making starters whenever you use liquid yeast.

yeah, i'll be doing starters from now on. i didn't plan things out right and got too excited once i got home from the LHBS

could you explain why 150 is better for an ipa? I'm still learning how mash temp affects the final outcome and haven't brewed an IPA since the days of extract.

 

[Redlantern]

MAsh temp affects if the process yields fermentable or non fermentable sugar. Two different enzymes are present that make the sugar (alpha and beta amylase) They are active at different temps.
Chart below should help. I target 148 - 150 for my IPA's

Edit - Beta makes fermentable sugar - Alpha? not so much...

 

[wstcstnative]

Added: There should be nothing wrong with the beer - maybe a tad sweeter than it should have been.

I've read about bottle bombs in this situation...should i go a little lower on the corn sugar when bottling? i don't have the setup for kegging yet. in a 5 gal batch i usually add about 4-5oz of corn sugar boiled in a about 1-2 cups of water to bottle carbonate

 

[kh54s10]

Not if you take FG readings two days apart and they are the same. If there is any drop you are still getting fermentation and you need to wait. I use this calculator to determine priming amounts: http://www.northernbrewer.com/priming-sugar-calculator

I think, given the high OG, the high mash temperature and the attenuation to range, that you have FG. Pitching more yeast will not do anything if all the consumable sugars are gone.

How long has it been dry hopped? I would give it between 3 and 7 days, check the gravity again then if the same go ahead and bottle it.

 

[wstcstnative]

Not if you take FG readings two days apart and they are the same. If there is any drop you are still getting fermentation and you need to wait. I use this calculator to determine priming amounts: http://www.northernbrewer.com/priming-sugar-calculator

I think, given the high OG, the high mash temperature and the attenuation to range, that you have FG. Pitching more yeast will not do anything if all the consumable sugars are gone.

How long has it been dry hopped? I would give it between 3 and 7 days, check the gravity again then if the same go ahead and bottle it.

sounds good, thank you.
dry hopped last night which was exactly two weeks in primary. been kept somewhat stable temp in my pantry.

 

[eadavis80]

The lower your mash temp (I would not mash below 149 or so for an IPA) the more fermentable your wort will be. That means you'll have more available sugar for the yeast to eat, thus a higher ABV. GENERALLY I try to mash around 151-152 for most beers (wheat, IPA, amber) and maybe a few degrees higher for stouts and porters as I like those usually a little sweeter with a heavier mouthfeel. Lower mash temp = higher ABV possibility/thinner mouthfeel. Higher mash temp = lower possible ABV/heavier mouthfeel.

 

[wstcstnative]

So it turns out that this beer finished at 1.014, only 0.002 away from my target final gravity! I ferment in my pantry and it's been pretty warm where I live the past couple weeks, making the ambient house temp in the mid to high 70s (we don't have A/C), so that probably had something to do with the finishing gravity. After two weeks in primary this was 1.020 so I dry hopped and then after another 10 days it finally finished! I'm sure glad it did. the 1.020 sample i tasted wasn't great, but i think the final product now will be just fine.