stuck fermentation - give up and bottle?

[RobertMuldoon]

Hello all,

I brewed a milk stout on 12/29. Came in with a perfect OG of 1.055 It was cranking along until we had lost power for about a day and the temp dropped down into the low 50's. I took a gravity reading after I got it back up to 65, 1.027. Thought "ok, no worries, give it another week. Target FG is 1.015, you're not TOO far." Still at 1.027. During the third week, I warmed up to 70 and gave it a few swirls, no luck. I then talked to my LHBS, and they recommended pitching US-05. No luck there either. A week after that they recommended I rack to a secondary, no luck. After that, they recommended a champagne yeast as a final resort, still no luck. This milk stout was in primary for 4 weeks and secondary now for 2 and has been repitched twice. Still at 1.027.

My question - the only other option I can think of it racking onto a yeast cake (which I will have in another week or two) OR just bottling it and putting it into a bomb shelter.

I don't want to risk spoiling the beer with all of the nasties in a spent yeast cake, but it is still pretty sweet. Thanks for any input.

 

[thadass]

How does it taste?

 

[eastoak]

is it an extract beer? it might be done if so.

 

[sweetcell]

I don't want to risk spoiling the beer with all of the nasties in a spent yeast cake, but it is still pretty sweet. Thanks for any input.

unless you have sanitation issues, there shouldn't be any nasties in a yeast cake (at least not so many many as to ruin your beer). any chance the brew shop told you about these nasties? maybe they don't want you re-using a cake, they would rather have you buy new yeast.

the likely reason why pitching US-05 didn't work is that the yeast wasn't active, and you pitched it into a low pH environment that contained alcohol. any chance you just sprinkled it on top of the wort? the yeast were dormant and they woke up to an unhospitable enviro. they said "eff this" and went back to sleep.

pitching champagne yeast after brewers yeast rarely works. champagne yeast can only digest simple sugars. simple sugars are the first thing that brewers yeast eats, so by the time you pitch the champagne yeast there is nothing left for it to eat. furthermore, champagne yeast is a killer yeast - it will kill off all brewers yeast (thus ensuring that any complex sugars left will remain unfermented). champagne yeast is great if you want to do late sugar additions to jack up your beer in alcohol.

so what to do? if you have a yeast cake available, i would cold crash your stout to drop out as much champagne yeast as you can, then pitch on to the cake and hope that the cake gets active quickly. or you could look into adding amylase to break down the complex sugars into something the champagne yeast can eat. or, better yet, you can chalk this up as a learning experience, cut your losses, and enjoy a sweet milk stout.

 

[RobertMuldoon]

How does it taste?

A little too sweet.

is it an extract beer? it might be done if so.

Extract, but with a few pounds of steeped grains.

so what to do? if you have a yeast cake available, i would cold crash your stout to drop out as much champagne yeast as you can, then pitch on to the cake and hope that the cake gets active quickly. or you could look into adding amylase to break down the complex sugars into something the champagne yeast can eat. or, better yet, you can chalk this up as a learning experience, cut your losses, and enjoy a sweet milk stout.

Thanks for all the info. I'm leaning towards pitching onto the yeast cake, as I'm certain there is no risk of infection. My LHBS told me there would be so much trub, it could spoil the product, but I suppose they are a business after all.

 

[Conman13]

I've never heard of a fermentation being stuck so stubbornly like that. Are you sure your thermometers are correct and all? How warm was the wort when you pitched the new yeast? Did you hydrate and do everything else correctly?

 

[Bsquared]

How did you take the final gravity reading, hydrometer or refractometer? This is a milk stout so you added lactose, if so how much?

 

[Calder]

Did you use a refractometer?

"A few pounds of steeped grain", these could contribute .011 of unfermentable sugars (that assumes 3 lbs). What was your recipe?

Not knowing the full ingredient list, and hearing you used a lot of speciality grain, I would say you are done, and the yeast is telling you that too.

 

[RobertMuldoon]

I've never heard of a fermentation being stuck so stubbornly like that. Are you sure your thermometers are correct and all? How warm was the wort when you pitched the new yeast? Did you hydrate and do everything else correctly?

I agree, this brew is being very stubborn, makes me think maybe it is just done. My thermometer and hydrometer are both spot on. The wort was 70F when I repitched both times. As per the instruction by the LHBS, I did't rehydrate, just sprinkled it on. They actually specifically told me not to rehydrate.

How did you take the final gravity reading, hydrometer or refractometer? This is a milk stout so you added lactose, if so how much?

Hydrometer. 1lb. of lactose. Here is the recipe...

6.6 lb. Munton's Extra-Light Malt Extract
1 lb Lactose
3/4 lb. Munton's Crystal Malt 60° L
1/2 lb. Munton's Chocolate Malt
1/4 lb Thomas Fawcett Pale Chocolate
1/4 lb Munton's Roasted Barley 675° L
1 oz. Northern Brewer Hops (Bittering)
Wyeast #1098 British Ale Yeast

 

[BigFloyd]

That pound of lactose by itself accounts for +.007 on your FG, so it's really at 1.020. I understand that 1.020 FG can happen using extract.

You also have quite a bit of roasted and medium crystal grain in their, the bit that it contributes to the gravity is mostly unfermentable.

IMO, it does no good (as you found out) to sprinkle dry yeast into a beer that has fermented that far. If adding yeast to a stuck fermentation, it's most effective to make a starter and pitch it at high krausen. If using dry yeast to make the starter, rehydrate it first.

I'm confused as to how transferring a beer off the yeast cake could possibly relieve a stuck ferment.

 

[eastoak]

did the target FG take into account the 1lb of lactose? in any event it looks like there plenty of unfermentables in that beer so i'd bet it's done.

 

[sweetcell]

As per the instruction by the LHBS, I did't rehydrate, just sprinkled it on. They actually specifically told me not to rehydrate.

i question the quality of information that your LHBS is giving you. dry yeast should always be rehydrated - and especially if you're going to pitch it into a partially fermented beer.

 

[grasshopper1917]

There is debate whether dry yeast 'should always be rehydrated'. You will find valid arguments on both side of the fence. In defense of the clerks at the home brew store sometimes they are just trying to help best they can. I know locally they are usually just college kids who like to brew a bit, they usually mean well but don't know all the answers all the time.

As for the beer I agree fermentation may be as complete as its getting.

 

[BigFloyd]

In defense of the clerks at the home brew store sometimes they are just trying to help best they can. I know locally they are usually just college kids who like to brew a bit, they usually mean well but don't know all the answers all the time.

That may well be true (depending on the store), but if they don't know much about trying to unstick a potentially stuck fermentation, they shouldn't be giving the sort of advice they gave the OP. They were wrong (or at least partially so) on all three things that they told him to do.

 

[RobertMuldoon]

That pound of lactose by itself accounts for +.007 on your FG, so it's really at 1.020. I understand that 1.020 FG can happen using extract.

You also have quite a bit of roasted and medium crystal grain in their, the bit that it contributes to the gravity is mostly unfermentable.

IMO, it does no good (as you found out) to sprinkle dry yeast into a beer that has fermented that far. If adding yeast to a stuck fermentation, it's most effective to make a starter and pitch it at high krausen. If using dry yeast to make the starter, rehydrate it first.

I'm confused as to how transferring a beer off the yeast cake could possibly relieve a stuck ferment.

Live an learn, I learned a lot from this batch for sure. The guy said that racking to a secondary would take it off the bad yeast that stalled and leave only yeast that are in suspension.

Another question though - will all the unfermentables effect the OG as well? Meaning my 1.055 OG was actually 1.048 accounting for the lactose?

Thanks for the replies everybody! Everybody on this forum is very nice and helpful. I'm used to car forums where people are d-bags and not helpful at all.

 

[sweetcell]

Another question though - will all the unfermentables effect the OG as well? Meaning my 1.055 OG was actually 1.048 accounting for the lactose?

unfermentables are included in your OG. remove the unfermentables and both your OG and FG should fall by the same amount. without lactose your OG would have been 1.048 and *your* FG (i.e. the way this fermentation went) would have been 1.020 (assuming the lactose accounts for 7 points).

assuming that the lactose was in the recipe, the target FG of 1.015 takes into account the lactose.

 

[eastoak]

Live an learn, I learned a lot from this batch for sure. The guy said that racking to a secondary would take it off the bad yeast that stalled and leave only yeast that are in suspension.

this is bad information, very often repeated, but wrong. the best place for a fermenting beer is on the yeast. once it's reached it's final gravity there is more debate as to whether to move it or not but at least you are moving a beer that is fully attenuated.