how slow is "stopped"?

[GeneDaniels1963]

I made up a 1 gal batch of cherry dark sour, fermented with some sour trub (in fridge) from a batch last year. SG was 1.100. It has fermented VERY slow. I was aiming for it to finish around 1.020-25, but was stalled last week at 1.063. I have tried yeast starters twice, maybe kicks up the ferment for a very short while, but then back to almost nothing.

It has been fermenting for almost 2 months, so I thought it was a hopeless cause. But before dumping it, I decided to check again, and today it is down to 1.055. Not much of a drop, but it is something. If I watch closely I can see an occasional bubble rise to the top.

As for flavor, it has good cherry and is sour, maybe even too sour. But that is not the problem, I don't mind lots of sout. Even the sweet I can deal with, but the low ABV (3.9% right now) just makes it a waste to me. Will it continue to ferment at this snail's pace and make it down to something drinkable over a few months?

Should I wait it out? (for how long?)
Should I cut it with some spirits? (how much and what kind?)
Should I brew another batch and blend? (I'm afraid to throw good wort after bad)

Any suggestions are appreciated

 

[brownni5]

What was in the sour blend? Brett? Very high OG for a mixed ferm beer, but it's not done. 2 months is nothing in the life of a sour beer - this one will likely need a year or more to reach terminal, especially if only the Brett, which works very slowly, is working at this point.

 

[GeneDaniels1963]

It was Wyest 5223-PC Lactobacillus brevis, its the only sour yeast my brew shop had at that time.

 

[myndflyte]

So you've pitched normal yeast at some point and it still won't ferment? What yeast are you using and is it sensitive to acidity?

 

[GeneDaniels1963]

Yep, did yeast twice. But it is still only down about 45 grav points

 

[GeneDaniels1963]

Yep, did pitched Nottingham yeast twice. But it is still only down about 45 grav points

 

[yoop89]

I have tried yeast starters twice

If you just pitched the Lacto "trub" it is likely that you soured your 1.100 wort and didnt really ferment it. Adding yeast starters after that pitch, depending on timing, was most likely deadly to the yeast not to mention that you would need a pretty healthy starter or a few packs of Notty to ferment a 1.100 wort on its own. Add in a low PH environment and it just adds to the stress.

If you want to get a yeast starter going look up "acid shock starters" and try to adapt that method with whatever yeast you want to try but build it up a few extra steps prior to adding to the main ferment.

EDIT- missed that this was only a 1 gallon batch, disregard my mention of pitch rate above.

 

[brownni5]

You say it's very sour - that's affecting the ability of the Sacch to ferment well. If it were me, and it's undrinkable (and to me, 1.055 would be), I would likely wait it out to see what happens. Adding a $10 Brett culture to a 1-gallon batch to me wouldn't be worth it, but that's likely the only way to get it down in the neighborhood of 1.020. Maybe dregs from another sour beer?

 

[GeneDaniels1963]

If you just pitched the Lacto "trub" it is likely that you soured your 1.100 wort and didnt really ferment it. Adding yeast starters after that pitch, depending on timing, was most likely deadly to the yeast not to mention that you would need a pretty healthy starter or a few packs of Notty to ferment a 1.100 wort on its own. Add in a low PH environment and it just adds to the stress.

If you want to get a yeast starter going look up "acid shock starters" and try to adapt that method with whatever yeast you want to try but build it up a few extra steps prior to adding to the main ferment.

EDIT- missed that this was only a 1 gallon batch, disregard my mention of pitch rate above.

Thanks for the advice. I found a "low tech" instruction for "acid shock starters" on Milk the Funk. Looks easy enough. I am going to wait another week to see what the gravity does. If it is still dropping I will probably just wait it out. If not, the I will try a acid shock starter.

 

[bleme]

Are you measuring FG with a hydrometer or a refractometer?
If a refractometer, how are you calculating the alcohol correction?

 

[GeneDaniels1963]

I am using a refractometer, and I use Northern Brewer's adjustment calculator:
https://www.northernbrewer.com/pages/refractometer-calculator

 

[jrgtr42]

Personally, I ferment my sours with a standard yeast first, then add in souring bugs later.
My go to is based on Russian River's Consecration, so it's basically a Strong Dark Ale, so I primary with Abbey Ale yeast, then once that's about done - it finishes around 1.020, I'll pitch the souring bugs and forget about it for a year. (not quite; there's a couple additions in between, but you know what I mean) At that point the bugs have brought it down around 1.010, so I'll pitch a bit of champagne yeast for bottling.

 

[GeneDaniels1963]

Well, I just checked it again, and it is down to 1.038, making it about 6.5%. It has some sour and even more vinegar taste, almost too much vinegar, but... the sour/vinagar kind of balances the high finishing grav.

I am still not sure what to think about it. I kind of like it, but the vinegar is right on the edge of too much for me.

 

[brownni5]

Well, I just checked it again, and it is down to 1.038, making it about 6.5%. It has some sour and even more vinegar taste, almost too much vinegar, but... the sour/vinagar kind of balances the high finishing grav.

I am still not sure what to think about it. I kind of like it, but the vinegar is right on the edge of too much for me.

It's dropped around 25 points since your first post a week ago - obviously it's not done, or at least wasn't last you checked. Sours sometimes require a lot of patience.

Too vinegary? That seems odd. Brettanomyces will produce acetic acid (i.e. vinegar) if exposed to too much oxygen, but you said there is no Brett in the blend. Acetobacter also produces acetic acid, and works well in the presence of oxygen. 1 gallon glass carboy/jug? It may be too late, but if acetobacter is present you shouldn't sample so often since sampling introduces oxygen. If you're sampling through a spigot from the bottom, well that theory is busted.

Might be worth a look at the acetobacter page on Milk the Funk to see if you think that sounds right.

 

[GeneDaniels1963]

Yeah, I was shocked with the drop. But I just got a new refractometer and I am pretty sure it is correct. Maybe putting it out on the porch in the sun raised the temp so much that it roused the yeasties.

As for sampling, I have probably done that 3 or 4 times over the months. Is that too much? The jug is full to the top, so not much headspace, but O2 certainly could have gotten in while it was stalled.

 

[brownni5]

Again, just speculating, but that in my opinion is too often to sample,i at least when sampling from the top. I typically don't sample my sours (or any of my beers) until I'm ready to package or if at least 6 months have passed (well, not clean beers). If I see my sours (with Brett) are at 1.005 or lower, I call that close enough to bottle. With enough patience, no need to worry about bottle bombs.

 

[GeneDaniels1963]

6 months, wow, that is a long time. I guess I will let this one sit for 2-3 more then test SG again. If it is stable, then I'll bottle it. If not???

Since its just 1 gal its not a huge loss if I toss it. But I like strange brews, so I am hoping this will turn out to be something strange yet drinkable