Stuck fermentation or wrong mash procedure?

[luizffgarcia]

Guys, i need some advice.

I have a beer in my primary looking like dirty water after 14 days fermenting. At day 10, after confirming that the fermentation had stopped for 3 days at 1025 i increased the temperature to up to 25c and still the fermentation is not going anywhere.

One important thing is, for the first time i tried the iodine test, which was failing, so i ended up mashing for a long time, 60 min at 65c and 50 min at 77c.

I am very confused here, is this a stuck fermentation that would not restart even raising the temperature AND shaking the carboy for a few days? Or is this the result of an extended 77c mash which extracted way too many complex sugars?

Thanks for the help

 

[Pariah3j]

What was your OG ? Might need more yeast pitched. I had this issue recently, had a really high OG and had to pitch a second thing of yeast to get it going again after it stalled out. Or you might need some Amylase Enzyme to help break up some of those sugars.

 

[luizffgarcia]

What was your OG ? Might need more yeast pitched. I had this issue recently, had a really high OG and had to pitch a second thing of yeast to get it going again after it stalled out. Or you might need some Amylase Enzyme to help break up some of those sugars.

Original was not too high, it was 1070... Don't you think the rest of the sugars are just complex sugars because of the extended high temperature mash time?

 

[unionrdr]

77C equals 170.6F, so the second mash temp was too high & likely denatured the enzymes to some extent. You need these enzymes from the malted grains for conversion to simple sugars. You could wind up with a lot of starch haze & unfermented wort.

 

[luizffgarcia]

77C equals 170.6F, so the second mash temp was too high & likely denatured the enzymes to some extent. You need these enzymes from the malted grains for conversion to simple sugars. You could wind up with a lot of starch haze & unfermented wort.

Makes sense, i think that is what happened...

Is there any way i can save this beer? I already decided not to waste hops in dry hopping, but i am even considering not bottling at all...

 

[TurnipGreen]

The other thing that I am starting to learn about designing beers is keeping an eye on attenuation.

Basically for any of my beers over 1065 I try to really research the yeast choice, especially if I want it to have a dryer finish with a lower gravity. I made a supper strong alt beer that got stuck. I raised the temp and that helped a bit but it never stopped again at 1018. It's still good and pretty well balance but I think it would be a bit nicer if it finished around 1014ish. In retrospect I could have tried pitching a more attenuative yeast.

170f is way too high to mash. But I was under the impression that once those conversions happened at your first temp they higher temp would just stop any further conversion. I think 168 is the manic number to stop enzime conversion. I honestly don't know what happens if you hold it there though?

 

[unionrdr]

I generally mash between 147F & 156F. I sparge after the mash @ 168F top 170F, this stops any further conversion, since that should have been completed during the mash. But that high temp should never be part of the mash cycle. Only after the mash is complete & you're sparging. Not much you can do about it now...

 

[doug293cz]

You can try adding some alpha amylase enzyme (avail at most LHBS's) to your fermenter. This will basically continue your mash conversion, but at fermentation temps (takes days instead of minutes.) Downside to adding amylase is that it can drive your FG too low, as there isn't really a way to stop its action.

Just out our curiosity, what was your grain bill?

Brew on

 

[luizffgarcia]

You can try adding some alpha amylase enzyme (avail at most LHBS's) to your fermenter. This will basically continue your mash conversion, but at fermentation temps (takes days instead of minutes.) Downside to adding amylase is that it can drive your FG too low, as there isn't really a way to stop its action.

Just out our curiosity, what was your grain bill?

Brew on

11.25 lbs. (5.1 kg) 2-row pale malt
1.66 lbs. (0.75 kg) wheat malt
0.625 lbs. (0.28 kg) crystal malt (15 °L)
0.42 lbs. (0.19 kg) dextrose (corn sugar)
0.21 lbs. (95 g) CaraPils malt

Step by Step
Mash in at 145 °F (63 °C) then ramp temperature to 152 °F (67 °C) for conversion. Mash out to 170 °F (77 °C). Boil for 90 minutes, adding hops at the times indicated in the ingredient list. Ferment at 68 °F (20 °C).

So, i mashed for 60 min and then raised the temperature to 77c. But since the iodine was still black (i know now that test sucks), i continued the 77c for too long. How long should i keep it at 77c btw? I use BIAG so i dont sparge...

 

[doug293cz]

11.25 lbs. (5.1 kg) 2-row pale malt
1.66 lbs. (0.75 kg) wheat malt
0.625 lbs. (0.28 kg) crystal malt (15 °L)
0.42 lbs. (0.19 kg) dextrose (corn sugar)
0.21 lbs. (95 g) CaraPils malt

Step by Step
Mash in at 145 °F (63 °C) then ramp temperature to 152 °F (67 °C) for conversion. Mash out to 170 °F (77 °C). Boil for 90 minutes, adding hops at the times indicated in the ingredient list. Ferment at 68 °F (20 °C).

So, i mashed for 60 min and then raised the temperature to 77c. But since the iodine was still black (i know now that test sucks), i continued the 77c for too long. How long should i keep it at 77c btw? I use BIAG so i dont sparge...

The higher temp will speed up the alpha amylase action until denaturing is complete. The alpha amylase enzyme is pretty much fully denatured after 10 minutes at 77˚C. Additional time really doesn't do anything, as far as I know.

Your grain bill should have had plenty of diastatic power to achieve full conversion. I don't see any concern there.

Brew on

 

[EarthwormJim]

Any chance the problem could be that you are reading the gravity with a refractometer and not a hydrometer?

 

[luizffgarcia]

Any chance the problem could be that you are reading the gravity with a refractometer and not a hydrometer?

Well i am using a refractometer, but i use calculators to that use the original brix to convert, and i do this for all my batches which finish around 1009, so i don't think this is a problem.

 

[luizffgarcia]

The higher temp will speed up the alpha amylase action until denaturing is complete. The alpha amylase enzyme is pretty much fully denatured after 10 minutes at 77˚C. Additional time really doesn't do anything, as far as I know.

Your grain bill should have had plenty of diastatic power to achieve full conversion. I don't see any concern there.

Brew on

Sorry i don't follow. The beer i have in the fermenter looks like swamp water, do you think i should just bottle it? Or try something else?

 

[doug293cz]

I'd try the amylase enzyme I suggested in an earlier post before you dump it. I don't think it's worth bottling in its current state.

Brew on

 

[dwhite60]

Your mash was done before you ramped up the temp. You can get full conversion in 30 minutes. You went an hour. You were done. The long period at 77C wasn't necessary.

If you have the same reading with either hydrometer or refractometer for three days, it's done. While your reading with the refractometer may not be correct, if it's not changing, it's done.

Let it sit a few more days. It'll probably clear. If it doesn't it might clear in the bottle. I've had that happen a few times.

Beer can sense your worry and will do things to you.

All the Best,
D. White