Over attenuation

[McUbermensch]

I recently brewed an IPA and ended up with a OG of 1.068 and an FG of 1.002. The anticipated FG was 1.012. I mashed at 151 degrees for 60 minutes.

Grains:
7# 2 row
12oz flaked oats
12oz white wheat malt

Yeast
Vermont ale

Fermented in 64 degree ambient temperature room.

The samples I've drawn taste and smell very bready/yeasty. I'm 99% sure it isn't infected. What could the problem be?

 

[Tiber_Brew]

My money is on Saccharomyces diastaticus

Saccharomyces diastaticus has the ability to ferment starch and dextrin, because of the extracellular enzyme glucoamylase, which hydrolyzes the starch/dextrin to glucose. Since it's Saccharomyces, it doesn't produce acid or 4-ethylphenol like most infections do, so it won't taste sour or funky. It will, however, dry the heck out of your beer.

If you don't get headaches from sulfites, I'd add campden tablets at the recommended dosage, cold crash, then rack off of the resulting trub. Better yet, filter to .5 microns if you have that capability. If you are bottle conditioning, add fresh yeast with your priming sugar at bottling. If you're force carbonating in the keg, no worries.

 

[madscientist451]

Did you try to cold crash it yet? That might drop the yeast out, don't know about the "bready" flavor. That might fade with some aging. Where did you get the Vermont Ale yeast?

 

[tooldudetool]

That fg seems very unlikely, as it would be impossible for your yeast to attenuate that far, and as you said you are 99% sure its not infected... I would look at how you are measuring the fg. Did you use a hydrometer or a refractometer? Refractometers don't measure correctly when alcohol is present. If you used a hydrometer did you correct for temperature (if necessary)? Have you tasted it? That fg would be so dry it would feel like it was sucking the moisture out of your tongue...

 

[McUbermensch]

That fg seems very unlikely, as it would be impossible for your yeast to attenuate that far, and as you said you are 99% sure its not infected... I would look at how you are measuring the fg. Did you use a hydrometer or a refractometer? Refractometers don't measure correctly when alcohol is present. If you used a hydrometer did you correct for temperature (if necessary)? Have you tasted it? That fg would be so dry it would feel like it was sucking the moisture out of your tongue...

I used a hydrometer and did correct for temperature. The hydrometer has correctly read the FG of two other batches I have waiting to be bottled. As for the taste, I can only liken it to a super dry IPA. It in no way taste infected.

It's currently cold crashing.

 

[Chrisbrewbeers]

I really want to know how you got 1.068 out of less than 10 lb grain. My beers are all 1.004-1.008 for some reason. I had a few lower but most like that. I think it is mash time but I really have no idea. I want an IPA to finish 1.012-1.016 like everyone says theirs do.

 

[helibrewer]

I recently brewed an IPA and ended up with a OG of 1.068 and an FG of 1.002. The anticipated FG was 1.012. I mashed at 151 degrees for 60 minutes.

Grains:
7# 2 row
12oz flaked oats
12oz white wheat malt

Yeast
Vermont ale

Fermented in 64 degree ambient temperature room.

The samples I've drawn taste and smell very bready/yeasty. I'm 99% sure it isn't infected. What could the problem be?

Was this a 5 gallon batch? Did you add any water after taking your OG reading?

Your OG should have been about 1.057

2 row = 34 ppg x 7# = 238
oats = 30 ppg x .75 = 22.5
wheat = 33 ppg x .75 = 285.5

285.5 points per pound per gallon / 5 gallons = 57.1 points or 1.057

Something seems off here

 

[McUbermensch]

I really want to know how you got 1.068 out of less than 10 lb grain. My beers are all 1.004-1.008 for some reason. I had a few lower but most like that. I think it is mash time but I really have no idea. I want an IPA to finish 1.012-1.016 like everyone says theirs do.

Beersmith estimated the gravity would be 1.064 but my temperature corrected hydrometer reading was 1.068.

Was this a 5 gallon batch? Did you add any water after taking your OG reading?

Your OG should have been about 1.057

2 row = 34 ppg x 7# = 238
oats = 30 ppg x .75 = 22.5
wheat = 33 ppg x .75 = 285.5

285.5 points per pound per gallon / 5 gallons = 57.1 points or 1.057

Something seems off here

This was a 3.5 gallon test batch. No water was added after boil.

Something is off I just can't figure out what it is.

 

[Tiber_Brew]

As for the taste, I can only liken it to a super dry IPA. It in no way taste infected.

I think it is infected, though. See my response above.

 

[McUbermensch]

I think it is infected, though. See my response above.

Tasted another sample yesterday. I'm now in agreement with you. It is almost undrinkable now as it is very dry and boozy. The sample I tasted yesterday reminded me of a young mead a buddy of mine made with Fleishmann's bread yeast.

 

[Tiber_Brew]

Tasted another sample yesterday. I'm now in agreement with you. It is almost undrinkable now as it is very dry and boozy. The sample I tasted yesterday reminded me of a young mead a buddy of mine made with Fleishmann's bread yeast.

That sounds like S. diastaticus to me for sure. It's not a very well known contaminant amongst homebrewers, but it will ruin a batch if given the chance.

 

[McUbermensch]

That sounds like S. diastaticus to me for sure. It's not a very well known contaminant amongst homebrewers, but it will ruin a batch if given the chance.

After reading up on s.diastaticus I'm 100% that is the culprit. Thank you for your help. This batch is getting tossed.

 

[olotti]

Now where would this infection come fro? Sorry for your loss of beer, did you clean and sanitize everything real well? Did u ferment in a bucket or carboy?

 

[McUbermensch]

Now where would this infection come fro? Sorry for your loss of beer, did you clean and sanitize everything real well? Did u ferment in a bucket or carboy?

I am super particular about cleaning and sanatizing. I clean my equipment before and after each brew. This beer was fermented in a brand new bucket. This is my first lost batch in 5+ years of brewing so I'm not super bummed. It was also a test batch so not much money was invested.

 

[brewcat]

I really want to know how you got 1.068 out of less than 10 lb grain. My beers are all 1.004-1.008 for some reason. I had a few lower but most like that. I think it is mash time but I really have no idea. I want an IPA to finish 1.012-1.016 like everyone says theirs do.

To get that OG it would have to be a smaller batch.

Maybe mash temp needs raised for your IPA? Or maybe you need to mash out?

 

[Chrisbrewbeers]

That's true smaller batch would do it, mash temp makes no difference that I can see so it's time or mash out likely. I'm in process of tracking it down. It's really the times that 12 lb grain got me 8% or higher beer that I feel like higher FG would be helpful, but I don't do that much.