US-05 90% attenuation

[An Ankoù]

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.

It's possible, but not likely. Especially when you consider that traditionally, beer was fermented in open vessels. Albeit with a yeast that has a much shorter lag time.
I reckon your beer's going to be fine.

 

[Braumeister]

Thanks will let you know

This is what the ispindel said it did

 

[Sadfield]

Brewers sanitise, which is reducing pathogens to manageable levels, rather than sterilising, which is removing all pathogens. Because of this, fermentation becomes a competition between desirable brewing yeast and everything else for that malty energy source. Therefore pitching enough healthy yeast is vital to load the competion in the yeasts favour. This is how breweries successfully ferment in open fv. Plus, they have an advantage as they aren't brewing in houses, with bacteria, fungus and yeast laden kitchens and bathrooms.

If the mash profile was the issue, wouldn't the linked forum be full of the same complaint? Scrolling through it, I don't see anyone complaining of 90% attenuation from following the original recipe even when they've used us05. There's enough anecdotal evidence there to suggest the mash temp and yeast choice, isn't the problem. 90% attenuation is unusual the vast majority of brewing yeasts.

Off flavours are dependent on flavour thresholds. A contamination may not be sufficient enough to be detectable by smell or taste, however it will from the outset start to breakdown and/or consume sugars, which will increase attenuation. Even if it's only breaking down starch into sugars that yeast can consume.

It may not be a contamination, but your process and laggy fermentation has opened the door to one.

I'd still check that the mash temperature is accurate with a calibrated thermometer. To rule out the possibility you aren't making a more fermentable wort than you think you are.

 

[Sandimas]

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

It'll get in during the brewing process, after the boil, before you start fermenting.

 

[Braumeister]

It'll get in during the brewing process, after the boil, before you start fermenting.

I see!

Brewers sanitise, which is reducing pathogens to manageable levels, rather than sterilising, which is removing all pathogens. Because of this, fermentation becomes a competition between desirable brewing yeast and everything else for that malty energy source. Therefore pitching enough healthy yeast is vital to load the competion in the yeasts favour. This is how breweries successfully ferment in open fv. Plus, they have an advantage as they aren't brewing in houses, with bacteria, fungus and yeast laden kitchens and bathrooms.

If the mash profile was the issue, wouldn't the linked forum be full of the same complaint? Scrolling through it, I don't see anyone complaining of 90% attenuation from following the original recipe even when they've used us05. There's enough anecdotal evidence there to suggest the mash temp and yeast choice, isn't the problem. 90% attenuation is unusual the vast majority of brewing yeasts.

Off flavours are dependent on flavour thresholds. A contamination may not be sufficient enough to be detectable by smell or taste, however it will from the outset start to breakdown and/or consume sugars, which will increase attenuation. Even if it's only breaking down starch into sugars that yeast can consume.

It may not be a contamination, but your process and laggy fermentation has opened the door to one.

I'd still check that the mash temperature is accurate with a calibrated thermometer. To rule out the possibility you aren't making a more fermentable wort than you think you are.

yes I’ll check the thermometer reading is right.

The instructions on the US-05 pack say 1 pack is good for 5 gallons. I don’t think that’s an underpitch is it? I don’t think anyone pitches 2 packs of that unless it’s a high gravity beer. 1 pack should be good up to 1.060.

 

[An Ankoù]

I see!

yes I’ll check the thermometer reading is right.

The instructions on the US-05 pack say 1 pack is good for 5 gallons. I don’t think that’s an underpitch is it? I don’t think anyone pitches 2 packs of that unless it’s a high gravity beer. 1 pack should be good up to 1.060.

This is worth looking at:
https://www.homebrewtalk.com/threads/us-05-very-high-attenuation-85.599397/

 

[dmtaylor]

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

I agree, it's important to use calibrated instrumentation. Great point.

US-05 and 1056 are considered to be comparable and interchangeable.

But they aren't really interchangeable. 1056 averages 75% attenuation, whereas US-05 is a descendant that consistently attenuates to 83%. A difference of 8% average is very significant.

 

[dmtaylor]

The instructions on the US-05 pack say 1 pack is good for 5 gallons. I don’t think that’s an underpitch is it? I don’t think anyone pitches 2 packs of that unless it’s a high gravity beer. 1 pack should be good up to 1.060.

Definitely not an underpitch.

 

[Sadfield]

Definitely not an underpitch.

What would explain the observed lag time?

But, they aren't really interchangeable. 1056 averages 75% attenuation, whereas US-05 is a descendant that consistently attenuates to 83%. A difference of 8% average is very significant.

Consistently to 83%. So not to 90+% unless there's something else acting on the wort? +7% difference is pretty significant.

 

[An Ankoù]

Just as a matter of interest, how are these attenuation rates established by the yeast labs? Do they use a standard wort with a fixed mix of glucose, maltose and m-triose and, perhaps, some dextrins? If not, how can they make a comparison.
So what if we get rid of all the dextrins and m-triose, woudn't we get 100% attenuation?
What if we chucked a pack of US-05 into a solution of just glucose together with some nutrient. Wouldn't we get full attenuation?
Do you see where this is leading? I'll bet an extract brewer would get within range every time.

 

[Sadfield]

Do you see where this is leading? I'll bet an extract brewer would get within range every time.

Why wouldn't a grain brewer?

The predicted attenuation for the recipe on Brewfather was 81% based on ingredients and mash parameters. That should be achievable. Rather than being 10% out. Why aren't the others from the posted thread experiencing the same discrepancy? Why are they achieving an abv of 5.5% from c1.053 OG?

 

[dmtaylor]

What would explain the observed lag time?

24 hours lag is really not that bad. That being said, there are probably dozens of variables affecting lag time. Number one is that we don't know how the yeast was treated before purchase. Maybe it experienced 37C weather during shipping. Maybe this batch was just cranky because it didn't like the phase of the moon. Who knows.

Consistently to 83%. So not to 90+% unless there's something else acting on the wort? +7% difference is pretty significant.

Mash time. And maybe a great batch of base malt with extra enzymes. Maybe lack of calibration of instrumentation. A perfect storm of several variables.

 

[dmtaylor]

Just as a matter of interest, how are these attenuation rates established by the yeast labs? Do they use a standard wort with a fixed mix of glucose, maltose and m-triose and, perhaps, some dextrins? If not, how can they make a comparison.
So what if we get rid of all the dextrins and m-triose, woudn't we get 100% attenuation?
What if we chucked a pack of US-05 into a solution of just glucose together with some nutrient. Wouldn't we get full attenuation?
Do you see where this is leading? I'll bet an extract brewer would get within range every time.

Who knows how the yeast labs measure attenuation. I'm not using their data for the numbers I report. I'm using real-world data from myself and the interwebs.

Without dextrins and maltose and maltotriose, we could get 100% apparent attenuation, or even higher. For example, many ciders, wines, and meads containing mostly simple sugars will attenuate to a finishing gravity of 0.992-0.996. Same could theoretically happen with beer if certain sugars could be taken out (a challenging task).

I would expect US-05 in a glucose solution to finish below 1.000.

 

[dmtaylor]

The predicted attenuation for the recipe on Brewfather was 81% based on ingredients and mash parameters. That should be achievable. Rather than being 10% out. Why aren't the others from the posted thread experiencing the same discrepancy? Why are they achieving an abv of 5.5% from c1.053 OG?

Sounds like a problem with Brewfather's calculations. If they offered me a job I might consider it. But I mean, honestly, of course, no calculators are ever going to be perfect for every situation. Not possible.

Others won't report discrepancies if they don't measure or don't care. And I ain't reading 35 pages in the other thread to see what they've reported because, for as much time as I waste on homebrewing forums, I don't have THAT kind of time.

 

[Sadfield]

A perfect storm of several variables.

Indeed, that's why I asked multiple questions in my first post.

Although having you point out how consistently US-05 normally attenuates, I'm more inclined to view such super-attenuation is being a contamination. Its what I'd expect from mixed fermentation or a diastatic strain.

The software is predicting an FG of 1.010. That looks reasonable to me from the mash temperature.

 

[An Ankoù]

Why wouldn't a grain brewer?

Malt extract is a concentrate of a standardised mash with a fixed ratio of the various saccharides. Grain brewers have a bit more control- we tend to mash at a high temperature for low attenuating, full-bodied beers and mash low for stronger less-full-bodied beers. We can also vary the time of the mash, we don't have to stop when starch end-point is reached. If our temperatures are out, or the thickness of the wort or one sack of grain is slightly different to the last then we can get variations. But if we used, say, M J light Malt Extract all the time then we'd need to be using different yeasts to get different degrees of attenuation.

I'm more inclined to view such super-attenuation is being a contamination. Its what I'd expect from mixed fermentation or a diastatic strain.

Fair point. It's worth asking the OP what he fermented in that vessel before and what yeast he used. I understand some of these diastaticus strains can produce a protective biofilm and might hang about. I'm not persuaded that contamination is necessarily the case, though, as I get similar attenuation with US-05 and zero gushers.

 

[dmtaylor]

Indeed, that's why I asked multiple questions in my first post.

Although having you point out how consistently US-05 normally attenuates, I'm more inclined to view such super-attenuation is being a contamination. Its what I'd expect from mixed fermentation or a diastatic strain.

Of course contamination is a possibility. But I wouldn't say likely or expected. I would estimate odds of contamination at less than 50/50. It is much more likely some combination of instrumentation calibration, mash time, & yeast selection.

 

[Sadfield]

Less than 50/50 isn't great odds. How would you improve them? A bigger pitch of viable yeast to reduce the lag time?

 

[Sadfield]

Malt extract is a concentrate of a standardised mash with a fixed ratio of the various saccharides. Grain brewers have a bit more control- we tend to mash at a high temperature for low attenuating, full-bodied beers and mash low for stronger less-full-bodied beers. We can also vary the time of the mash, we don't have to stop when starch end-point is reached. If our temperatures are out, or the thickness of the wort or one sack of grain is slightly different to the last then we can get variations. But if we used, say, M J light Malt Extract all the time then we'd need to be using different yeasts to get different degrees of attenuation.

The brewing software accounted for all this and predicted 81% attenuation. The same as the beer being cloned. The OP says that they achieved the correct time and temperature. A homebrewers mash process should be just as accurate as a malt extract manufacturers. mash.

 

[dmtaylor]

Less than 50/50 isn't great odds. How would you improve them? A bigger pitch of viable yeast to reduce the lag time?

Actually I wouldn't change anything. A concerned person could pitch more yeast but I see it as a waste. A 24-hour lag time is not bad at all.