What's the best way to save a stuck fermentation?

My lager has been fermenting for 3.5 weeks at 53 F. My OG was 1.059 and expected FG is 1.018. Three readings over the last two weeks were 1.041 (2 weeks ago), 1.041 (one week ago) and 1.037 (today). I have good temperature control and I was wondering should I

Turn up the temp a bit to try to resume fermentation? or
Pitch some more yeast and leave temp at 53?
Or something I'm not thinking of?

The optimal temp range for the yeast (Saflager S-23) is 48-59 F.
Also, I used a lot of dark malt extract (9.9 lbs) to get the gravity that high. I know darker extract has less fermentable sugars, but would this cause my FG to be significantly higher?

I would raise the temp a few degrees and see if that gets the yeast going again. It shouldn't affect flavor at this point.

A few of us were recently discussing this.

https://www.homebrewtalk.com/f163/slow-lager-fermentation-240390/

But just in summary, I would recommend raising the temperature a bit more and then maybe think about repitching. If you can get a few more points, they you might be able to just move into the D-rest, which could get you the rest of the way.

I should really stop posting until I've decided if I'm done answering, but I just read your post again. Next time you take a sample, add 1 tsp. or so of baker's yeast, or any dry yeast, and leave it at 70F for a few days. Then take a gravity reading of that sample; that should tell you where you should expect your final gravity to be.

Check this out as well:
http://braukaiser.com/wiki/index.php/Fast_Ferment_Test

I've personally never been able to get a stuck fermentation going again. I tried the "rousing the yeast" and raising the temperature and pitching dry yeast. Nothing seems to work. That being said, I don't think you have a stuck fermentation, but just yeast that drops really slowly. I would forget about the beer for at least another 2 weeks. As long as the gravity keeps dropping it's all good.

Four gravity points over two weeks is a serious red flag.

I will take it at face value that your temp control is really good. If that is the case, 53F is more than appropriate for your yeast. Look elsewhere.

As I see it, there are two possibilties.

First - tell us more about the yeast. You used S-23, right? Was it a fresh pack(s)? Was it being stored cold (not frozen)? Did you calculate the appropriate number of grams to pitch for a lager? Did you rehydrate in 100F water, or did you just sprinkle it into the wort? If so, what temp was the wort you sprinkled into?

Second - I'll post the obligatory, "It would help a lot if you shared the recipe" comment. I know you used extract, but I have seen all-grain recipes mashed correctly, but made with grains with no ability to convert. I'd imagine that if you used very dark extract, and a ton of crystal for steeping, you had a high gravity beer made with a ton of unfermentables.

So if the yeast turns out to be mistreated, you may have a chance of getting new yeast, treating it properly, and pitching it to finish the job - I actually would not bet on this scenario.

More likely, the wort was highly unfermentable. We will be better able to confirm that once the recipe is given. If this is the case (which I bet it is) your beer will be stuck at ~1.037. All the yeast in the world would not be able to process unfermentable sugars. At worst, you will have a batch of undrinkable beer, but you will be able to learn from the experience.

Let us know,
Joe

Here is everything I used in the beer

Partial Mash
1 lb 2row pale
1 lb crystal 60
1 lb chocolate

9.9 lbs (3 cans) Munton's dark liquid extract
1 lb Munton's dry amber extract

I know I mistreated and shocked the hell out of my yeast- this was only my third batch.
I rehydrated the yeast in about room temp, 70 F water, then pitched into wort about about 75 F, then immediately stuck the carboy in a cooler at 53 F. Prior to pitching, the 11.5 g yeast packet was stored in a fridge.

My OG reading was way lower than what i expected: 1.052
I wanted the gravity pretty high as this was supposed to be a doppelbock, and a professor who brews suggested I make a glucose solution and add it to the carboy.

I added enough glucose to bump the gravity up to 1.059, but I couldn't confirm this because the sugar was added a few days after fermentation had begun. However, I know I did the math right.

The sugar solution was pretty warm when I added it; impatience got the better of me and it was well over 100 F when i poured it in.

Have I thoroughly screwed this beer up? I've tasted it and while it has many of the flavor notes I'm looking for, there is a harsh fusel alcohol taste as well. I've since read a lot about how important it is to treat the yeast well, and I will not make these mistakes again.

Thanks for posting the recipe.

I tried getting the specs for Munton's but they require a stupid log-in to get any info, so I jumped over to Briess.

Here is their spec sheet for Dark LME

http://www.brewingwithbriess.com/Assets/PDFs/Briess_PISB_CBWTradDarkLME.pdf

And here is Amber LME

http://www.brewingwithbriess.com/Assets/PDFs/Briess_PISB_CBWSparklingAmberLME.pdf

Lets assume the products are similar enough for the sake of discussion.

Both extracts show as 75% fermentable, so even though I really suggest using Light LME and getting your color/character from mini-mash/steeping specialty grains, the extract is not the culprit. Even if you completely botched the mini-mash, it should have only made a small contribution to the fermentables in the wort.

I blame your yeast (but that is a good thing) or your measurement (that is a better thing).

If you are super confident that you are measuring gravity correctly, then throw out the measurement possibility, get some more dry yeast, rehydrate properly, and re-pitch. I am never a re-pitch guy, but in this case, since the final gravity is so ridiculously high, you are in yeast problem territory, not the more typical wort problem territory.

Just remember, rehydrate, covered, for 15 minutes in pre-boiled 100F water. Give it a stir with a sanitized spoon, and pitch. You are going to have some health issues because the initial pitch used up a lot of the nutrients in the wort, but it is better than nothing.

Good luck, and let me know what you think.

Joe

jfowler1 said:

Just remember, rehydrate, covered, for 15 minutes in pre-boiled 100F water. Give it a stir with a sanitized spoon, and pitch.

Click to expand...

No argument here but 100 degrees F sounds pretty high to rehydrate the yeast. I've read that it's a good strategy to rehydrate in water colder than the wort because apparently yeast that warm up to fermentation temp do better than yeast that cool down to it.

What's your rationale for using water at 100F?

bmurph said:

No argument here but 100 degrees F sounds pretty high to rehydrate the yeast. I've read that it's a good strategy to rehydrate in water colder than the wort because apparently yeast that warm up to fermentation temp do better than yeast that cool down to it.

What's your rationale for using water at 100F?

Click to expand...

Good question.

This is actually accessable through a sticky on the mead forum (of all places) but it references to an interview with Clayton Cone of Danstar. For a while I talked about rehydrating in 105F water, but someone told me it applied to wine yeast, so I felt stupid and kind of let it go. But after reading through the attached document, I am once again convinced that it is actually applicable to beer yeast, but the reference can be used for wine/mead. Maybe I'll e-mail Dr. Cone myself one day, but for now, I'll just offer the link and a copy/paste.

(sorry if the formats don't transfer cleanly)

http://home.comcast.net/~mzapx1/FAQ/Rehydrate.pdf

Although the following information was intended for dry beer yeast, I believe it underscores some of the
points made above, and provides a bit more technical detail (source: Dr. Clayton Cone, rec.crafts.brewing
03/03/03):
“Every strain of yeast has its own optimum rehydration temperature - all of them range between 95 F to
105F (most of them closer to 105°F). The dried yeast cell wall is fragile and it is the first few minutes
(possibly seconds) of rehydration that the warm temperature is critical while it is reconstituting its cell wall
structure. As you drop the initial temperature of the water from 95 to 85 or 75 or 65F the yeast leached out
more and more of its insides damaging the each cell. The yeast viability also drops proportionally. At 95 -
105 F, there is 100% recovery of the viable dry yeast. At 60F, there can be as much as 60% dead cells.
The water should be tap water with the normal amount of hardness present. The hardness is essential for
good recovery: 250 -500 ppm hardness is ideal. This means that deionized or distilled water should not be
used. Ideally, the warm rehydration water should contain about 0.5 - 1.0% yeast extract.
Dry Yeast Rehydration
Rev 1 (2/14/07)
For the initial few minutes (perhaps seconds) of rehydration, the yeast cell wall cannot differentiate what
passes through the wall. Toxic materials like sprays, hops, SO2 and sugars in high levels, that the yeast
normally can selectively keep from passing through its cell wall rush right in and seriously damage the cells.
The moment that the cell wall is properly reconstituted, the yeast can then regulate what goes in and out of
the cell. That is why we hesitate to recommend rehydration in wort or must. Very dilute wort seems to be
OK.
We recommend that the rehydrated yeast be added to the wort within 30 minutes. We have built into each
cell a large amount of glycogen and trehalose that give the yeast a burst of energy to kick off the growth
cycle when it is in the wort. It is quickly used up if the yeast is rehydrated for more than 30 minutes. There
is no damage done here if it is not immediately add to the wort. You just do not get the added benefit of that
sudden burst of energy. We also recommend that you attemperate the rehydrated yeast to with in 15F of
the wort before adding to the wort. Warm yeast into a cold wort will cause many of the yeast to produce
petite mutants that will never grow or ferment properly and will cause them to produce H2S. The
attemperation can take place over a very brief period by adding, in increments, a small amount of the cooler
wort to the rehydrated yeast.
Many times we find that warm water is added to a very cold container that drops the rehydrating water below
the desired temperature. Sometimes refrigerated, very cold, dry yeast is added directly to the warm water
with out giving it time to come to room temperature. The initial water entering the cell is then cool.
One very important factor that the distributor and beer maker should keep in mind is that Active Dry Yeast is
dormant or inactive and not inert, so keep refrigerated at all times. Do not store in a tin roofed warehouse
that becomes an oven or on a window sill that gets equally hot.
Active Dry Yeast looses about 20% of its activity in a year when it is stored at 75 F and only 4% when
refrigerated.”

So it's been six weeks since brew day and I'm still about 15 points above where I want to be. The cooler I keep the beer in is on my college campus and will soon become unavailable to me when the semester ends.

I'm gonna have to take it home shortly, but hopefully the warmer temp of my apartment will rouse the yeast a bit and dry out the beer. If I don't see activity soon after I warm it up, I'll have to pitch more yeast (which I already did about two weeks ago, and the SG has dropped maybe 3 points since then), and I'm wondering if it would be better to use a lager or ale yeast for this.

Also, should it be dry/liquid? If liquid should I make a starter for it?

I would wait to see if it ferments any more after you raise the temperature (let it go as high as 70F if need be), which I would suggest doing immediately, before the yeast completely go to sleep. You may be surprised at how quickly it finishes after you raise the temperature.

Just took the beer home a couple hours ago.

It's right at 70 in here; we'll see what happens soon.

Good luck! I hope it turns out!

The beer has spent a good 48 hours at 70 F and there's no activity. No bubbles in the airlock at all. Time to repitch?

And should it be ale or lager yeast?

Sounds like it probably is time. But before you do, take a gravity sample and perform a fast ferment test (you can just use dry or even bread yeast) to determine how far you can expect it to ferment; it can help you determine if it is worth repitching.

If you do repitch, I would probably recommend using an ale yeast at this point, as it is more likely to work, faster, and easier to work with.