US-05 90% attenuation

[Braumeister]

My current brew has supposedly fermented down from 1.054 to 1.005 which is 90%. It took 24 hours to get going but it’s just kept on going, it’s day 10 now. Brewfather has US-05 at 81% so how is this possible? Is it normal to get that low a gravity? I mashed 10 mins at 40, 90 at 66, 10 at 77. Is that why? Maybe I should just do 10 at 40, 60 at 68C, 10 at 77 next time? I changed it as I had trouble getting down to FG last time

It’s a little bit annoying as now the beer is quite a bit stronger than planned and I suppose drier.

It’s a Blue Moon clone which was supposed to be 5.5% but now might be 6.5%. I thought 5.5% was a little high for an easier drinker anyway, but will have to be a bit careful with drinking this one in the hot weather

 

[dmtaylor]

It's the total TIME of your step mashing that caused this. Next time try mashing for just 45-60 minutes total. So maybe 10 at 40C, 30-40 (instead of 90!) at 66C, 10 at 77C, and maybe skip the last step entirely (I would). Problem solved.

 

[Braumeister]

It's the total TIME of your step mashing that caused this. Next time try mashing for just 45-60 minutes total. So maybe 10 at 40C, 30-40 (instead of 90!) at 66C, 10 at 77C, and maybe skip the last step entirely (I would). Problem solved.

Thankyou! No idea where I got the idea of a 110 minute mash, what a wally

 

[Cheshire Cat]

Don’t step mash 60 minutes at 65 and a sparse at 75 for 20 minutes will do the job fine.

 

[Braumeister]

Don’t step mash 60 minutes at 65 and a sparse at 75 for 20 minutes will do the job fine.

OK you would go for 80 minutes total? I will try that.

I found where I got the 90 minutes at 66C, it was from the Blue Moon clone thread on homebrewtalk, from the Blue Moon brewer. Probably it doesn’t translate well to home brewing. Although I guess I added 20 minutes with the mash in and mash out which probably didn’t help matters.

Post in thread 'Blue Moon Clone'
Blue Moon Clone

 

[dmtaylor]

OK you would go for 80 minutes total? I will try that.

I found where I got the 90 minutes at 66C, it was from the Blue Moon clone thread on homebrewtalk, from the Blue Moon brewer. Probably it doesn’t translate well to home brewing. Although I guess I added 20 minutes with the mash in and mash out which probably didn’t help matters.

Post in thread 'Blue Moon Clone'
Blue Moon Clone

80 minutes might be fine with a different yeast. But you are using US-05 which is very highly attenuative, averaging 83% even on a bad day. Why aren't you using a witbier yeast, like Lalbrew Wit, or Mangrove Jack M21? Not that this will help the attenuation -- they still attenuate >80% typically.

Bottom line is I think 80 minutes is still a lot for these yeasts. So I guess I question the reasoning behind the 90 minutes from the original recipe. There's no good reason, especially for Blue Moon which is not as dry of a witbier as other examples.

 

[Braumeister]

80 minutes might be fine with a different yeast. But you are using US-05 which is very highly attenuative, averaging 83% even on a bad day. Why aren't you using a witbier yeast, like Lalbrew Wit, or Mangrove Jack M21? Not that this will help the attenuation -- they still attenuate >80% typically.

Bottom line is I think 80 minutes is still a lot for these yeasts. So I guess I question the reasoning behind the 90 minutes from the original recipe. There's no good reason, especially for Blue Moon which is not as dry of a witbier as other examples.

Yes thanks for this, it makes sense. Will definitely dial the mash duration down. Apparently they use an American ale yeast for Blue Moon, rather than a Belgian Wit yeast, even though they advertise it as a Belgian Wit. Not sure if that’s still the case but that’s what that chap Wayne said, who apparently brewed it for Coors. Hopefully it still turns out ok, sample seemed promising.

 

[Sadfield]

If the actual brewer of the beer suggests that mash schedule with US05, then it should be repeatable. Likewise, if the brewing software suggesting 81% attenuation for those ingredients then that should be roughly where you should finish up.

Rather than changing the mash schedule or yeast, next time. I suggest you should be looking at why a proven recipe has over-attenuated. (Edit) Or, as your initial post hints to, under-attenuated previously. This suggests the problem is process related and not a recipe fault.

Is your thermometer calibrated?
Does your mash maintain a consistent temperature?
How much yeast did you pitch? Into what volume of wort?
Is there any possibility of contamination? Have you used saison yeasts recently?
Have other beers over-attenuated?

 

[jceg316]

I would agree with @Sadfield here. I went from 60 min infusion mash to 90 mins, 10 min mash out and fly sparge which takes an hour. The increased mash time improved my efficiency quite drastically but didn't break up the sugars any more (which would lead to a dryer beer). What would lead to this is mashing at lower temperatures. Something else it could be is an infection.

 

[Braumeister]

Ok thanks both, if it’s an infection would the beer taste bad? I could pull another sample

 

[Braumeister]

If the actual brewer of the beer suggests that mash schedule with US05, then it should be repeatable. Likewise, if the brewing software suggesting 81% attenuation for those ingredients then that should be roughly where you should finish up.

Rather than changing the mash schedule or yeast, next time. I suggest you should be looking at why a proven recipe has over-attenuated. (Edit) Or, as your initial post hints to, under-attenuated previously. This suggests the problem is process related and not a recipe fault.

Is your thermometer calibrated?
Does your mash maintain a consistent temperature?
How much yeast did you pitch? Into what volume of wort?
Is there any possibility of contamination? Have you used saison yeasts recently?
Have other beers over-attenuated?

Thermometer should be fine, it’s just built in the system and temp was consistent
I pitched 1 packet into 20 litres, didn’t rehydrate
I haven’t used saison before
No my last beer struggled to get down but that was higher gravity and a different yeast I may have under pitched

I’m just reading through the thread again and the brewer said he used 1056 or 1187 liquid yeasts which I think is American ale and Ringwood. Ringwood looks to be low attentuation, maybe that’s the problem, US-05 is not comparable. I didn’t consider attenuation, I was thinking flavour

 

[Sadfield]

I wouldn't assume that the thermometer is accurate, just because it's built in.

US-05 and 1056 are considered to be comparable and interchangeable. And you have over-attenuated for US05, rather than selected a too attenuative yeast.

By a number of pitch rate calculators, one packet in 25L of 1.054 wort is an under-pitch (by 45% on Brewer's Friend). This is evident by the 24hr lag phase and long, ongoing fermentation of more than 10 days. Over-attenuation is often a symptom of a contamination having been able to take hold due insufficient brewers yeast being pitched.

 

[Braumeister]

Ok thanks @Sadfield, I’m guessing if it’s contaminated or infected it will have strange off flavours and taste bad, or will it still be drinkable?

 

[foxy]

If the actual brewer of the beer suggests that mash schedule with US05, then it should be repeatable. Likewise, if the brewing software suggesting 81% attenuation for those ingredients then that should be roughly where you should finish up.

Rather than changing the mash schedule or yeast, next time. I suggest you should be looking at why a proven recipe has over-attenuated. (Edit) Or, as your initial post hints to, under-attenuated previously. This suggests the problem is process related and not a recipe fault.

Is your thermometer calibrated?
Does your mash maintain a consistent temperature?
How much yeast did you pitch? Into what volume of wort?
Is there any possibility of contamination? Have you used saison yeasts recently?
Have other beers over-attenuated?

I would add one more possibility to Sadfield's list, fermentation temperature, this can also increase the FG.

 

[Sandimas]

I’m guessing if it’s contaminated or infected it will have strange off flavours and taste bad, or will it still be drinkable?

Sometime it is drinkable, sometimes not. Be careful if you're bottling, as if infected it'll keep generating CO2 and the bottles may go bang.

It certainly sounds like an infection to me. Might just be wild yeast in the air, lots of us stop brewing mid-summer due to this. I thought I'd got away with it this year (had it previous years) but my last brew in late May has it and the bottles are foaming like crazy. All brews prior to this are fine, and I've only just done my next brew as tried to avoid mid-summer. Would also add that I've done over 250 brews many with US05 and it always attenuates around the 80% mark so definitely something amiss with your brew.

 

[Covrich]

Could be possible some wild yeast which this time of year is not uncommon could have got in and attenuated it.

Best way to check is, to try it. It will be drier than anticipated though but possibly perfrctly drinkable.

 

[An Ankoù]

My current brew has supposedly fermented down from 1.054 to 1.005 which is 90%. It took 24 hours to get going but it’s just kept on going, it’s day 10 now. Brewfather has US-05 at 81% so how is this possible? Is it normal to get that low a gravity? I mashed 10 mins at 40, 90 at 66, 10 at 77. Is that why? Maybe I should just do 10 at 40, 60 at 68C, 10 at 77 next time? I changed it as I had trouble getting down to FG last time

It’s a little bit annoying as now the beer is quite a bit stronger than planned and I suppose drier.

It’s a Blue Moon clone which was supposed to be 5.5% but now might be 6.5%. I thought 5.5% was a little high for an easier drinker anyway, but will have to be a bit careful with drinking this one in the hot weather

Seems perfectly normal to me. Just looked back through my brewing records and last autumn I made 3 X 25L batches with an OG of 1050 -1052 and FG of 1004-1006 ie 90% attenuation. later I made a couple of batches with CML Five with the same results. I mash overnight with a single-step infusion mash at a corrected starting temperature of 64-65C, which is gradually declines overnight. I like drier beers,
I think people jump to the conclusion that there's an infection far too quickly. Unless you have grounds to suspect something is wrong, look to the process first. All the beers mentioned above were primed and bottled and I'm still drinking them. If they were infected, they'd all be gushers by now, but, even after 9 months, they're still normally carbonated.

(My trusty hydrometer is out by two degrees, which I correct for. In any case, using the same hydrometer for start and finish gravities will always give the same gravity difference provided the "outness" doesn't change in between.)

Which leads me to ask, did you correct you hydrometer reading for the temperature of the sample? Mind you, it would only be one degree difference at current ambient temperatures.

 

[Braumeister]

Seems perfectly normal to me. Just looked back through my brewing records and last autumn I made 3 X 25L batches with an OG of 1050 -1052 and FG of 1004-1006 ie 90% attenuation. later I made a couple of batches with CML Five with the same results. I mash overnight with a single-step infusion mash at a corrected starting temperature of 64-65C, which is gradually declines overnight. I like drier beers,
I think people jump to the conclusion that there's an infection far too quickly. Unless you have grounds to suspect something is wrong, look to the process first. All the beers mentioned above were primed and bottled and I'm still drinking them. If they were infected, they'd all be gushers by now, but, even after 9 months, they're still normally carbonated.

(My trusty hydrometer is out by two degrees, which I correct for. In any case, using the same hydrometer for start and finish gravities will always give the same gravity difference provided the "outness" doesn't change in between.)

Which leads me to ask, did you correct you hydrometer reading for the temperature of the sample? Mind you, it would only be one degree difference at current ambient temperatures.

Yes I think you’re right, it’s most likely the mash temp and time that made it attenuate more. I suppose infection isn’t impossible but it’s less likely. The last hydrometer reading was 1.009, and that was after I let it go flat for a day, it was 1.012 initially, when it was probably 18C. It’s stopped at 1.005 off the ispindel reading, I’ll take a sample today and check it with the hydrometer, it might not be that low.

 

[Braumeister]

Sometime it is drinkable, sometimes not. Be careful if you're bottling, as if infected it'll keep generating CO2 and the bottles may go bang.

It certainly sounds like an infection to me. Might just be wild yeast in the air, lots of us stop brewing mid-summer due to this. I thought I'd got away with it this year (had it previous years) but my last brew in late May has it and the bottles are foaming like crazy. All brews prior to this are fine, and I've only just done my next brew as tried to avoid mid-summer. Would also add that I've done over 250 brews many with US05 and it always attenuates around the 80% mark so definitely something amiss with your brew.

Interesting thanks, how can wild yeast get in I wonder though? It is sealed from outside air during fermentation.

 

[Braumeister]

Could be possible some wild yeast which this time of year is not uncommon could have got in and attenuated it.

Best way to check is, to try it. It will be drier than anticipated though but possibly perfrctly drinkable.

Thanks, good idea, I’m going to try it today, it tasted good last time I check a couple of days ago. I didn’t know wild yeast can be a possibility to get into a brew.