FG high, stuck fermentation or just the recipe.

[labradorbeer]

I brewed a 5G batch of chocolate milk stout 3.5 weeks ago with this grain bill:

10# 2 row
1# chocolate malt
1# pale chocolate malt
1# roasted barley
1# lactose

OG was 1.078.
I messed up and forgot to make a starter so I pitched the only pack of US-05 I had hoping for the best. fermentation started pretty good but got to 1.040 and has stayed there, tried warming to 72F and no restart. this is my first time using lactose so I'm not sure if thats contributing to my high gravity but I have a feeling its due to the under pitch of yeast. the beer taste's really good and isn't overly sweet, taste's about right comparing it to the commercial milk stouts I've had.

so what do you all think is going on and what do you think I should do? I will be doing a black IPA this weekend maybe so I have the option to rack this stout onto that cake once its done if nessary.

 

[pittbrewing]

I made a CMS the other month that finished high as well, I believe at around 1.026-1.028. Its possible that its done, but you could make a starter with another pack of yeast and pitch it at high krausen. If you just pitched another pack without a starter idk if it would do much since it already has a decent amount of alcohol in it


EDIT: my og was about 10 points lower than yours too, for comparison

 

[chickypad]

Lactose is about 35 ppg so would only account for about 7 extra gravity pts in a 5 gal batch. 1.033 still sounds on the high side for a 1.078 stout with 05, maybe you mashed on the higher end?

 

[labradorbeer]

mash target was 154 but it did creep up a little higher then that at times,I'm doing BIAB and this was only my second beer using my new induction burner over propane so I'm still figuring it out. also I rechecked my notes and apparently I cant remember 3.5 weeks ago, my OG was 1.080.

 

[IslandLizard]

Current gravity measured with hydrometer or refractometer?

 

[labradorbeer]

all measured with hydrometer.

 

[IslandLizard]

all measured with hydrometer.

I was hoping you had used a refractometer without a correction formula that compensates for alcohol present. That would have been the simplest fix.

If it doesn't taste too sweet, Milk Stouts are very forgiving in that regard, drink as is. If you're bottling you will need to keep an eye on carbonation progress, then when done, store very cold (<40F), or it may decide later to kick up again.

Repitching onto the upcoming IPA cake is a big toss up. Don't ruin 2 beers.

A stalled fermentation could be due to old yeast, underpitching, and/or lack of adequate oxygenation/aeration during pitching. 1.078 is pretty high for a single pack of US-05. I doubt the higher residual gravity is from mashing 2 degrees high.

 

[labradorbeer]

if I can some more US-05 in town (only one store here that sells homebrew supplies and its mostly towards wine) I will try a repitch I think, if not I will just keg it and drink as is. the lower % doesn't bother me and I like how it tastes now so just as well.

 

[IslandLizard]

if I can some more US-05 in town (only one store here that sells homebrew supplies and its mostly towards wine) I will try a repitch I think, if not I will just keg it and drink as is. the lower % doesn't bother me and I like how it tastes now so just as well.

Just pitching a pack of fresh dry yeast in an under-attenuated beer may not resume fermentation, due to alcohol being present. Pitching a good size starter at high krausen has generally more success to revive stalled fermentation.

Is it possible the mash temps were way off, causing lots of unfermentables?

I had an Old Ale stall at 1.032 after pitching 2 packs of properly rehydrated fresh S-04, in well aerated 1.090-some wort. It wouldn't budge, whatever I tried. A small temp drop at the tail end of fermentation may have been the cause.

I'd keg it and enjoy as it. Carbonation will make it taste fuller, thicker, chances are that extra bit of sweetness will work well with that. The sensation of drinking fresh creamy milk.

 

[labradorbeer]

I kegged the stout as it was and it’s not bad, there’s a little sweetness but it doesn’t taste out of place. I’m brewing a Hefeweizen here now and after the stout I’m double checking my temps with a second thermometer and I noticed my mash temp top center is 7-8 degrees higher then the temp shown on my kettle thermometer. So that means the stout was really mashed in at around 160. Strange that the Irish blonde ale I did just before the stout on the exact equipment setup turned out fine.