82% attenuation?

[Redtab78]

Just wondering, but is it possible to achieve 82% attenuation from wyeast northwest ale 1332? If my math is correct and my ipa started at 1.072, and has finished at 1.010, that's 82%, how did I mange to get this? I did make a starter with 1 smack pack, but the starter was only 1L og of starter wort was 1.038 (ish) and had it on the stir plate for about 2 days, then cold crashed for about 6 hours, decanted and pitched into 80 degree wort, sat in the fermentation chamber at exactly 66 degrees for 9 days.

Is it typical to get a higher then advertised attenuation with a stir plate? I have never gotten this high before, so I was wondering what I did in my process to do this, thanks.

 

[dmtaylor]

That does seem odd. I calculate more like 86% attenuation. 1332 yeast is supposed to max out closer to 71%. Did you add a lot of simple sugars? Cane sugar? Candy sugar? Honey? Maple syrup? That could do this. Otherwise, makes me wonder if you might have contamination. Pitch rate and temperatures don't matter at all honestly.

 

[Redtab78]

No, nothing of the simple sugar variety...just the grains, mashed in at 152, 14# of standard stuff, 2 row, tad bit of crystal 60l, and a tad bit of Munich....but I am at a loss.

If it's an infection, how could I find out what it is? I just removed the airlock and looked down in and there is nothing that I can see on top like I have seen in other post.

 

[SanPancho]

maybe OG measurement was off. it happens some times. wort was too hot, too cold, etc.

or could be contamination. bottle one up and let it sit for a while. brett could go on eating all the way down to 1.001 or lower. if its a bottle bomb, or a huge gusher, then it was most likely brett or other wild yeast.

maybe keep the bottle somewhere it wont hurt anyone/thing if it does go boom.

 

[dmtaylor]

If you don't see or taste anything odd, then it's probably not contamination. I was only guessing.

Like SanPancho says, could also be measurement error, which could have happened anywhere with the gravity readings, mash temperature readings, whatever. Hard to know for sure.

 

[TheMadKing]

maybe OG measurement was off. it happens some times. wort was too hot, too cold, etc.

This

If your wort was 80 degrees when you pitched and you didn't chill your gravity sample down to mid 60's your OG reading was significantly off.

Also, unrelated, but cold crashing for 6 hours and decanting is basically the same thing as dumping half your starter down the drain. You need to cold crash for at least 48 hours to get all the yeast to settle out.

also, @dmtaylor pitch rate and temperature ABSOLUTELY matter. They both affect attenuation rate and total attenuation because they both affect overall yeast health.

Test it for yourself by making a batch of starter wort and splitting it, underpitch one, over pitch one, and ferment 2 at the same inoculation rate and widely different temperatures (60 and 80 for example). You WILL get different levels of attenuation. Overpitching will cause greater attenuation, and fermenting warmer will also increase attenuation.

http://braukaiser.com/blog/blog/2012/06/09/pitching-rate-experiment/

http://braukaiser.com/wiki/index.php?title=Understanding_Attenuation

 

[dmtaylor]

If your wort was 80 degrees when you pitched and you didn't chill your gravity sample down to mid 60's your OG reading was significantly off.

Also, unrelated, but cold crashing for 6 hours and decanting is basically the same thing as dumping half your starter down the drain. You need to cold crash for at least 48 hours to get all the yeast to settle out.

Great points.

also, @dmtaylor pitch rate and temperature ABSOLUTELY matter. They both affect attenuation rate and total attenuation because they both affect overall yeast health.

Test it for yourself by making a batch of starter wort and splitting it, underpitch one, over pitch one, and ferment 2 at the same inoculation rate and widely different temperatures (60 and 80 for example). You WILL get different levels of attenuation. Overpitching will cause greater attenuation, and fermenting warmer will also increase attenuation.

Not necessarily true, not true in my experience, and definitely not "ABSOLUTELY". Just a couple of examples (of many available all over the interwebs):

http://brulosophy.com/2016/11/07/ye...-vs-overpitch-in-a-lager-exbeeriment-results/

http://brulosophy.com/2016/08/01/fe...-pt-6-frankenyeast-blend-exbeeriment-results/

Cheers all.

 

[TheMadKing]

Great points.



Not necessarily true, not true in my experience, and definitely not "ABSOLUTELY". Just a couple of examples (of many available all over the interwebs):

http://brulosophy.com/2016/11/07/ye...-vs-overpitch-in-a-lager-exbeeriment-results/

http://brulosophy.com/2016/08/01/fe...-pt-6-frankenyeast-blend-exbeeriment-results/

Cheers all.

Not sure if Marshall had a typo or these pictures are not what he actually measured, but the one on the left (cooler fermentation) is reading 1.005 not 1.004 as he states.

 

[dmtaylor]

Not sure if Marshall had a typo or these pictures are not what he actually measured, but the one on the left (cooler fermentation) is reading 1.005 not 1.004 as he states.

Right you are!

 

[flugelizor]

Old thread, I know. But I just want to throw in my case.
I just brewed an IPA with wyeast northwest ale 1332
OG=1.067, FG=1.010
attenuation = 84%

Fermented under 68F ramped up to 71F
All grain, plus 1lb cane sugar per 9 gallon batch.

First keg tastes a bit boozy (vodka?)
We will see if the next keg is better after aging a while.

 

[dmtaylor]

I've never used the 1332 yeast. Maybe it just attenuates much more than the manufacturer claims. Maybe it is able to eat some complex sugars like a saison yeast. Hmm.

 

[chris000]

getting over 80% with wine yeasts for sure, but ale yeasts is rather rare and the one you mentioned should be around 70%.
I think the cause is more likely in the gravity reading; e.g. 2 different (non-calibrated) hydrometers used for OG and FG, lots of suspended particles during OG measurement, air bubbles, reading hot sample without temperature compensation (@65C a 1.066 reads for example just 1.05)

 

[flugelizor]

OK, Chris00,
Here is how I measured:

The OG was read two or three times with a temperature compensating refractometer.
the FG was read with the refractometer(1.031), and converted (1.012). then also read with a hydrometer (1.010)to compare.

Just for accuracy sake, I just read FG again with degassed and warmed beer 1.010.
I will concede 1.012 reading below the liquid level, instead of looking down from the top.

I just checked both calibrations against tap water. They are spot on zero.

So that's 81% apparent attenuation.

 

[thehaze]

I think you just got lucky, but that is not a bad thing.

Regarding what chris000 said above, I kinda disagree: I have a Belgian ale in bottles, which I fermented with a combination of T-58 and Brewferm Blanche and I got 81% attenuation, down from 1.066 to 1.012.

I also have an IPA with S-04, T-58 and Brewferm Blanche in bottles: down from 1.070 to 1.012. That is 83% AA.

Both beers were mashed at 154.4F and had no sugars in the boil. Simple grain bills with Pilsner, Wheat and Flaked Wheat. Hydrometer is calibrated and reads properly.

I can also add that T-58, which I use regularly for belgian beers I brew for some friends, is a poor attenuator, that clocks around 70%. I usually get between 75 and 81% AA with this yeast, using sugar as late additions.

So it is definitely possible that 1332 has some hidden traits, which we/nobody is/are not aware of it.

 

[dmtaylor]

So it is definitely possible that 1332 has some hidden traits, which we/nobody is/are not aware of it.

We are now! Maybe anyway. I've added a note to my yeast database for future reference -- expect attenuation closer to 81-85%, not as reported by the mfr.

 

[flugelizor]

I was always a bit wary of attenuation numbers.
I always thought attenuation was more a function of yeast health combined with fermentability of the sugars.

I am guessing if I used this yeast on pure honey, I could get FG down to 1.000.

 

[dmtaylor]

I don't believe health has much to do with it. If your yeast is 100% dead, then yeah, it won't ferment. But a little viable yeast will attenuate the same as a major overpitch of the same yeast -- I'd expect no difference in attenuation between an under and over pitch.

In a mead, many (most?) yeasts can take it all the way down to 0.992-0.994 if you let it. This yeast looks like it surely would do that.

 

[chris000]

...

I can also add that T-58, which I use regularly for belgian beers I brew for some friends, is a poor attenuator, that clocks around 70%. I usually get between 75 and 81% AA with this yeast, using sugar as late additions.
....

70% is what Fermentis also gives as ballpark figure.
What is interesting is you say that you use it regularly; do you mean re-use in the sense of multiple generations or buy it "new" all the time?
I'm wondering if you "trained" your yeast to certain prevailing conditions (3+ generations)

 

[thehaze]

70% is what Fermentis also gives as ballpark figure.
What is interesting is you say that you use it regularly; do you mean re-use in the sense of multiple generations or buy it "new" all the time?
I'm wondering if you "trained" your yeast to certain prevailing conditions (3+ generations)

No, I am pitching new yeast every time, due to the very low price of this particular yeast.

For reference ( I am not a skilled brewer, nor have years worth of experience ) I made the following beers using fresh packs of T-58:

1. A simple red belgian: Pilsner, Munich I, CaraAmber, Special B, Carapils ( 15% specialty malts ) got 75% attenuation with a 65C/149F mash temp. No sugar

2. A Belgian Dark-ish: Munich, Pilsner, Biscuit, CaraMunich III, Special B, Chocolate Wheat, CaraRed and Dark muscovado Sugar got 81% attenuation. The same 149F mash temp.

3. A leftover belgian. Pilsner, Chocolate, Special B, Biscuit and some sugar got 78% attenuation. Same mash temp as the others.

Common for all was a pitch temp. of around 64F which got to rise naturally until done, but this was not long as T-58 starts fermenting quickly and finishes pretty fast. Highest temp. was around 76F.

 

[chris000]

Everything that reduces flocculation; e.g. slightly higher temperature, rising, CO2 degassing during fermentation etc. can increase attenuation. However, I don't think that's the cause here.
and sorry didn't think of it before since I don't use adjuncts...
Highly fermentable sugars get your attenuation up - past the conservative values of the manufacturer, which are based on malt

 

[chris000]

oh and something else to keep in mind.
And I'm not saying anyone in this tread would have done anything wrong, but it is not uncommon to read them wrong or at least a little inconsistent.
Just an example; 1.055 to 1.011 gives you 80% right. But if you look for the next line; one might go 56-10 (82%) and another 54-12 (78%). So at the end of the day, there is no difference (in this example) if the values were 4% apart.