*never* ending fermentation

[sbaclimber]

First of all, I like a nice dry, bitter, hoppy beer as much as the next guy, but I have also apparently discovered the limit on dryness for the IPA I have been brewing. Once that limit has been passed, it just doesn't taste as good a should any more.
The problem is, after ~4 weeks in the bottle, my IPAs keep turning too dry. Brew after brew after brew...
After coming up with a recipe that gives me a beer I really like, I have been repeatedly brewing the same recipe over and over, in order to get my fermentation / conditioning process dialed in. I am pretty sure I have that process pretty much down pat now too, and am at a loss as to what to do against the last remaining problem.
The problem of yeast that just doesn't want to stop fermenting!
For example, my 2nd to last brew:
All grain, 93% pale ale malt, 7% CaraFoam. Mashed @ 67°C, sparged @ 75°C.
60min boil w/ bittering addition @ 60min and aroma @ 5min.
OG = 15.5° Plato (68% brewhouse efficiency)
WLP007 yeast, fermented @ 17°C for 2 weeks, raised temp to 23°C for one more week.
Bottled with no priming sugar at SG = 3.2° Plato. (no priming sugar, because I was fairly sure the SG would drop some more)
3 weeks later...SG = 2.8° Plato. At this point everything was good! The brew tasted the way I expected and I was happy with 82.5% attenuation.
2.5 weeks after that...SG 2.4° Plato. 85% attenuation, and things are starting to go south. Bitter and weird and grassy are the words that come to mind. Besides the fact that the attenuation is overshot and the C02 in the bottle is ever-increasing, what is happening!? Why is the yeast still this active!?
Like I said, this has been happening brew after brew...
Does anyone have any ideas?

 

[Nosybear]

First place I'd look is for contamination. Particularly given the off flavors you mention.

 

[sbaclimber]

First place I'd look is for contamination. Particularly given the off flavors you mention.

"off flavors"?
"grassy" was an exaggeration based on previous experience, and I shouldn't have used it as an example. Please don't bring that into any sort of analysis.
The extended fermentation time has been something I have been dealing with for over 2 years now. The only consistent factor being WLP007 and a >50% pale ale grain bill.
I did in fact have an infection last year which added some very off flavors (iodine), but have since replace all of my equipment. The off flavors have disappeared since then.
What I want to know, is why the yeast doesn't stop at 82%, or 84%, or 8x% attenuation...? Should I be mashing at maybe a higher or lower temp?

 

[UgliestLemming]

Higher temps make the less fermentable sugars.
Source:
http://beersmith.com/blog/2012/12/20/ma ... n-brewing/

 

[Ozarks Mountain Brewery]

after your 2 weeks or what ever time fermenting & conditioning , keep all beer ice cold, problem solved

 

[sbaclimber]

after your 2 weeks or what ever time fermenting & conditioning , keep all beer ice cold, problem solved

Hehe! Yeah, you're right, that would fix the problem.
If only I had a frig big enough...

 

[sbaclimber]

Higher temps make the less fermentable sugars.
Source:
http://beersmith.com/blog/2012/12/20/ma ... n-brewing/

That is exactly my question though...
"less fermentable sugars" doesn't mean "non-fermentable", and obviously the WLP007 continues to ferment them until it has eaten all it can. What bugs me, is that it takes so long.
So, I guess my detailed question is, do I...
a) mash at a higher temp, in the hopes that yeast will not be able to ferment the more complex sugars and simply give up earlier?
or...
b) mash at a lower temp, in the hopes that yeast will be able to more easily and quickly ferment all of the sugars?
What I am worried about with option b) is ending up with too high of an attenuation and a thinner drier beer. :?

 

[grainy one]

I seen this post and had to jump in. My 1st ? is, do you all ways use 007 yeast or have you had this problem with other yeasts?
2nd Do you all ways bottle with out priming sugar or was that just a once in a while thing?
007 yeast is vary dry yeast so it would be better I think, to mash at 154+ and don't mash for more then 60 min.
The use of a secondary fermenter may help shut down the yeast also. just do not use the yeast from that secondary fermenter for anything else or you will end up with even dryer beer in the next generation.

 

[UgliestLemming]

So, I guess my detailed question is, do I...
a) mash at a higher temp, in the hopes that yeast will not be able to ferment the more complex sugars and simply give up earlier?
or...
b) mash at a lower temp, in the hopes that yeast will be able to more easily and quickly ferment all of the sugars?
What I am worried about with option b) is ending up with too high of an attenuation and a thinner drier beer. :?

68 or 69 degrees C might keep just enough complex sugars to keep it from being too dry. If that doesn't work have you thought about adding dextrin to the boil to make up for the high attenuation?

 

[sbaclimber]

So, I guess my detailed question is, do I...
a) mash at a higher temp, in the hopes that yeast will not be able to ferment the more complex sugars and simply give up earlier?
or...
b) mash at a lower temp, in the hopes that yeast will be able to more easily and quickly ferment all of the sugars?
What I am worried about with option b) is ending up with too high of an attenuation and a thinner drier beer. :?

68 or 69 degrees C might keep just enough complex sugars to keep it from being too dry. If that doesn't work have you thought about adding dextrin to the boil to make up for the high attenuation?

I would consider the higher mash temp. Dextrin is an ingredient that I am not so keen on adding...

 

[sbaclimber]

I seen this post and had to jump in. My 1st ? is, do you all ways use 007 yeast or have you had this problem with other yeasts?

I have only ever (30+ brews) used WLP007.

2nd Do you all ways bottle with out priming sugar or was that just a once in a while thing?

I used to bottle with priming sugar, but the continuing fermentation was producing waaaaaaaaay too much CO2, so I decided to cut it out. The last 2 brews have been with no priming sugar, because I knew that the SG would drop significantly in the bottle.

007 yeast is vary dry yeast so it would be better I think, to mash at 154+ and don't mash for more then 60 min.
The use of a secondary fermenter may help shut down the yeast also. just do not use the yeast from that secondary fermenter for anything else or you will end up with even dryer beer in the next generation.

The high mash temp and secondary ideas sound good. I haven't used a secondary in a while. That sounds like it might help.

 

[The Brew Mentor]

SBA,
You have something else going on here (infection) :cry: .
Most likely something in your bottles or brew house.
It's time to review your cleaning and sanitizing processes and eliminate that possibility.
Brett, Lacto, and other things that can sour a beer and make it continue to ferment as you described are extremely difficult to get rid of. Even boiling water isn't enough in some cases.
I'd use a caustic wash followed with a rinse, then I'd go to an acidic wash and rinse and then a boiling water rinse ( Be very careful with any glass in this whole process). Replace any tubes and hoses. You may even change up your sanitizer, just to hit it full force.
Unless I'm missing something (ie letting the bottles get warmer than your ending fermentation temperature) this is the only thing that makes sense.
Brian

 

[sbaclimber]

Unless I'm missing something (ie letting the bottles get warmer than your ending fermentation temperature) this is the only thing that makes sense.
Brian

Oh, boy...I really hope it isn't an infection. :cry:
I just retested a brew I did back in January, which also slowly fermented slightly beyond what I had been aiming for. It has been in bottles for 3 months now, and the FG hasn't changed since what I measured ~2 months ago. Attenuation has remained at ~82.5%.
I think the following brew has also stopped now, after being in the bottle ~2 months and hitting an attenuation of 85%. That brewed was mashed slightly cooler and had a slightly higher efficiency.
I am thinking (and really really hoping) that I am simply misusing the WLP007. 80-85% attenuation is not unusual for that strain, but probably simply too high for the taste I am aiming for with the recipe I am using.
I will first try mashing at a slightly higher temp (+~1-2°C) again, to see if I can get the final attenuation down to around 80%.

 

[The Brew Mentor]

OK, after thinking a bit more, I'm wondering if your pitching healthy yeast? My though's are that if you're pitching incorrectly (hi, low, or unhealthy) that they are struggling to finish the fermentation process and therefore just barely munching away at the sugars. Are you starting with fresh yeast and making an appropriate starter?
You may also want to move to a more vigorous strain with less attenuative characteristics.
Most of my fermentation's are at terminal gravity in under 7 days. There's no reason you should be 4 weeks before bottling and not at terminal gravity.
I'd certainly assault my brewing/fermenting equipment if you're not 100% certain it's not and an infection.
Mash temperature shouldn't have anything to do with how long it takes to ferment. OG will.
Hope this helps.
Brian

 

[sbaclimber]

OK, after thinking a bit more, I'm wondering if your pitching healthy yeast? My though's are that if you're pitching incorrectly (hi, low, or unhealthy) that they are struggling to finish the fermentation process and therefore just barely munching away at the sugars. Are you starting with fresh yeast and making an appropriate starter?

Yes, I always use the calculator here and make a starter that at least qualifies as "Pro Brewer 1.0", even with fresh yeast.

You may also want to move to a more vigorous strain with less attenuative characteristics.

I've wanted to try WLP001 for a while now, but my normal supplier doesn't stock it. :-(

Most of my fermentation's are at terminal gravity in under 7 days. There's no reason you should be 4 weeks before bottling and not at terminal gravity.

Yes and no...
I have actually hit terminal gravity relatively quickly with this yeast before, but it was in summer and crazy warm. So, obviously, there were a lot of esters present in the finished product.
To avoid the esters, I have been brewing cold (17°C) for the first 2 weeks. 17° has successfully removed most of the esters, but is below the recommended fermentation temp.

 

[The Brew Mentor]

Most ale strains will ferment that low and I regularly ferment @ 17-18 C. I also warm up to 19 after a week and re-suspend the yeast, all without transferring from the primary. I'm usually in bright and conditioning in 10 days for a normal gravity beer and 14 for a bigger one.
Process aside, I think you may have something else going on.
Good Luck,
Brian

 

[sbaclimber]

Process aside, I think you may have something else going on.

You're probably right... :cry:

 

[7 Slot Brewing]

I believe WLP001 is a "Chico" strain and would be the samesimilar ads Safale us-05.

 

[sbaclimber]

I believe WLP001 is a "Chico" strain and would be the samesimilar ads Safale us-05.

Thanks for the tip! I can get Safale us-05 fairly inexpensively. And with it being dry, I can order more packs ahead of time (save on shipping) and store them.

 

[TheZel66]

Have you ever brewed a beer with Brett or any other souring yeast? That stuff is a challenge to remove from fermentors. It also might be a wild yeast strain introduced at some point, that is causing the issue. If you use a plaster fermentor, get a new one. If glass, soak for a few days using PBW. I did this and after three days, I saw flakes of stuff that came off the glass that I didn't know were there before. It solved my problem of high attenuating beers.