US-05 Very High Attenuation, 85%++

[jmitchell3]

Anyone else had experience with US-05 attenuating crazy high like this? My last 3 batches with this yeast have gone absolutely nuts. The last was a pale ale mashed at 152F that attenuated to 1.007 (90% pale ale malt, 5% victory, 5% C60). I use an electric temp controlled RIMS mash--so my mash temps are spot on...

 

[petrolSpice]

My last batch I made 3 weeks ago attenuated 90% with US-05. Mashed at 150F, fermented at 65F 8.1 gallons, used 2 packs rehydrated, yeast nutrient, and oxegenated. This is my normal process but the US-05 has never done this well, it's usually around 80% for me.

 

[dmtaylor]

It sure seems as though US-05 has mutated in just the last year or so. I can confirm that I too have noticed an obvious jump in attenuation of about 5-10% in recent history.

It's either a yeast mutation, or suddenly every malt on earth has experienced a sudden jump in diastatic strength, and I seriously doubt that.

 

[martiniw2olives]

My last batch I made 3 weeks ago attenuated 90% with US-05. Mashed at 150F, fermented at 65F 8.1 gallons, used 2 packs rehydrated, yeast nutrient, and oxegenated. This is my normal process but the US-05 has never done this well, it's usually around 80% for me.

Is the crush any different?

 

[petrolSpice]

Is the crush any different?

No, crush didn't change. Besides, crush should not have any appreciable effect on attenuation.

 

[jmitchell3]

My last batch I made 3 weeks ago attenuated 90% with US-05. Mashed at 150F, fermented at 65F 8.1 gallons, used 2 packs rehydrated, yeast nutrient, and oxegenated. This is my normal process but the US-05 has never done this well, it's usually around 80% for me.

Interesting...

 

[millsbrew]

Have the same experience. Got 87%. 1.055 down to 1.007 in 9 days. Kegged it right away so it wouldn't keep going. I think O2 and low mash temps are the cause.

 

[A2HB]

When I first started brewing back in 2014 I primarily used US-05 and I usually attained upper 80's to low 90's attenuation percentages. Typical gravity's would go from the 1.070's to below .010 on first pitch, with resulting yeast slurry pitches yielding similar results. I always figured it was a beast of a strain and kept using it for that reason.

I'm on liquid yeast now and only use 05 in emergency situations these days though

 

[benco]

Here's my experience with 05. I know there's a many kinds of yeast out to use depending on what your making. Yes it goes low, I love it. I mainly make ipas with it. It should do petrolSpice 8.1 gallons with one pack easily. Anyway I'm always around 1.010 and I don't rehydrate.

 

[FatDragon]

One more data tick: I've had many US-05 beers in the 85-90% range. A simple ~1.055 pale ale grainbill mashed ~152 and fermented ~65 seems to attenuate in the upper 80's almost every time.

 

[LordRogan]

I seem to have a beer that, according to my calculations, is at 0.9 and still fermenting. How is this possible?!

Here is the recipe and my process:

25 litres

12 oz Melanoidin
11 lb 2 row
1 lb Cara Pils
3.7 oz acidulated
.5 lbs sugar (after mash)

Mash Ph 5.4 at 120
OG at 1.063
137 IBUs

66 for 60 mins
78 for 10 mins

Boil for 75 mins

2 oz Chinook 75mins

1 oz Centennial 40 mins

1 oz Centennial 25 mins

.7 oz Huell Melon 0 mins

1 oz Chinook 0 mins

Pitched two packs of dry Safale 05 ( Mrmatly said 1.5 so added extra .5 for yeast wort death potential) Fermented at a constant 18.2 degrees with a slow climb to 21 as airlock activity decreased. Only three days so far in primary but calculations say 0.9 and 10.88%!?!

Maybe refractometer needs calibrating but was good for last brew.

Confused.com

 

[Lefou]

So you had a great conversion, a highly fermentable mash, and a vigorous ale yeast. If you're doing a pale ale or variation of an IPA don't be surprised if US-05 goes beyond the stated alcohol tolerance and attenuation level.
I've used this yeast to levels above 12% ABV, so mash carefully and choose your starting fermentation gravity wisely.
I'm wondering ....if your original gravity was 1.063, you shouldn't be anywhere near 10%, you should be closer to 7% max.

 

[LordRogan]

So you had a great conversion, a highly fermentable mash, and a vigorous ale yeast. If you're doing a pale ale or variation of an IPA don't be surprised if US-05 goes beyond the stated alcohol tolerance and attenuation level.
I've used this yeast to levels above 12% ABV, so mash carefully and choose your starting fermentation gravity wisely.
I'm wondering ....if your original gravity was 1.063, you shouldn't be anywhere near 10%, you should be closer to 7% max.

I know. You're right. All these things are healthy. I just panic when gravity drops below 1!

How are you doing your abv calculation as I keep coming up with higher numbers?
I'm using: https://www.brewersfriend.com/refractometer-calculator/

Cheers.

 

[Lefou]

I use an online calculator (Brewer's Friend).
If your hydrometer/refractometer is calibrated well, using your stated OG and 87% apparent attenuation would yield an FG around 1.008 and ABV of 6.96%.
I've had one of my non-sour, well-attenuated ales drop to 1.004 before. That was a blonde ale with WLP-001, using a step mash method, and the gravity measurement was taken weeks after bottle-carbing. I would expect a saison to do this, but if you have a highly fermentable wort that has converted well, a healthy yeast pitch will yield a dry beer no matter what is printed as the claimed tolerance level.

 

[Lefou]

Furthermore, you should expect somewhat of a drying effect. You added a half pound of sugar (sucrose). It's easily converted to fructose/glucose and the yeast will consume this quickly.

 

[LordRogan]

I use an online calculator (Brewer's Friend).
If your hydrometer/refractometer is calibrated well, using your stated OG and 87% apparent attenuation would yield an FG around 1.008 and ABV of 6.96%.
I've had one of my non-sour, well-attenuated ales drop to 1.004 before. That was a blonde ale with WLP-001, using a step mash method, and the gravity measurement was taken weeks after bottle-carbing. I would expect a saison to do this, but if you have a highly fermentable wort that has converted well, a healthy yeast pitch will yield a dry beer no matter what is printed as the claimed tolerance level.

I was aiming for a dryer beer, just as a slight experiment into dryer IPAs. My 66oc is on the lower end of the scale and favours Beta Amylase, which, as I'm sure you know, leaves more fermentable sugars. That coupled with the added .5lb of sugar had me expecting a low FG....just not this low...and still going!

Brewers Friend has me at.....oh wait.....I ****ed up. Just double checked.

FG at 10.12 thus far so all well within my happy place and abv at 6.8%.

You nailed it sir. Sorry to have publicly panicked! Hahaha.

I'm feeling it at the moment as my last beer went from 10.54 to 10.12 in 1.5 days. Made me think something was off in my brewhouse.

Thanks all

 

[Silver_Is_Money]

A long time ago there were rumors that US-05 was selectively evolved out of Danstar Nottingham. Since Nottingham can attenuate to these recently observed levels, and assuming some level of potential truth to the rumor (with admittedly no grounds upon which to do so), perhaps US-05 is merely reverting back to the norm over time, and essentially devolving back into being more along the lines of the parent Nottingham.

 

[Lefou]

... and possibly our friend LordR. will quite likely end up with a dry, ester-rich, and possibly fruity IPA for his efforts instead of a neutral, hop forward beer with a light-to-moderate body you'd normally expect from a run of the mill IPA.
Sometimes the yeast will surprise you with something better than you expected.

 

[LordRogan]

A long time ago there were rumors that US-05 was selectively evolved out of Danstar Nottingham. Since Nottingham can attenuate to these recently observed levels, and assuming some level of potential truth to the rumor (with admittedly no grounds upon which to do so), perhaps US-05 is merely reverting back to the norm over time, and essentially devolving back into being more along the lines of the parent Nottingham.

My aforementioned 1.5 day attenuation with primary was with Nottingham.