Understanding Attenuation

[sleepspeaking]

Ok so I have a Belgian going.
I noticed the White Labs vile I used to make my starters says its attenuation is 73-78%. Starting gravity was 1.077, and two weeks ago it was 1.015. Which puts apparent attenuation around 80% and actual around 65%. So which is it that white labs lists, apparent or actual. AND THEN... My concern is that I've reached the limit for this yeast, and it won't carbonate in the bottle.

This batch is still bubbling away, slowly...

If I've reached the attenuation limit of this yeast, would pitching champagne yeast at bottling be a viable option?

Suggestions?

 

[Big Monk]

Ok so I have a Belgian going.

I noticed the White Labs vile I used to make my starters says its attenuation is 73-78%. Starting gravity was 1.077, and two weeks ago it was 1.015. Which puts apparent attenuation around 80% and actual around 65%. So which is it that white labs lists, apparent or actual. AND THEN... My concern is that I've reached the limit for this yeast, and it won't carbonate in the bottle.



This batch is still bubbling away, slowly...



If I've reached the attenuation limit of this yeast, would pitching champagne yeast at bottling be a viable option?



Suggestions?

How much sugar did you use? I just got 85% AA with WY3787 using 10% sugar. I'd wait and see if I could get a steady reading over a couple of days before calling it.

I plan on using Red Star Premier Cuvee to bottle after cold crashing it.

 

[sleepspeaking]

I used 20% invert sugar. I'm thinking I'll get my final gravity just fine, but I'm concerned I won't get much past that and it won't carb up.

 

[Big Monk]

I used 20% invert sugar. I'm thinking I'll get my final gravity just fine, but I'm concerned I won't get much past that and it won't carb up.

What was your gravity?

 

[ajdelange]

So which is it that white labs lists, apparent or actual.

Apparent. Most home brewers aren't willing to go to the trouble to measure actual attenuation (though it isn't hard).

AND THEN... My concern is that I've reached the limit for this yeast, and it won't carbonate in the bottle.

When you add priming sugar they will get going again (unless you have waited too long or exceeded their alcohol tolerance).

 

[sleepspeaking]

What was your gravity?

1.077 og
1.015 when it went to the secondary

 

[Big Monk]

1.077 og
1.015 when it went to the secondary

Adding more yeast at bottling time is a judgement call. I like it because I seem to get faster, predictable and more consistent carbonation.

I don't use a secondary either.

 

[GuldTuborg]

Ok so I have a Belgian going.
I noticed the White Labs vile I used to make my starters says its attenuation is 73-78%.

Don't put too much stock in those numbers. They're what you might expect out of a very average wort, but mainly they're just helpful to compare strains against one another, too see which might attenuate a little more or less. Wort composition makes a far bigger difference on attenuation than yeast selection, with only a couple rare exceptions. It wouldn't be difficult at all to make wort that gets you 100% AA or 50% AA with that strain, for example (you might not like drinking either, depending, but it can easily be done).

My concern is that I've reached the limit for this yeast, and it won't carbonate in the bottle.

There's no limit based on percent attenuation. If the yeast are alive, and have food (sugar), they will continue to ferment, clear past 100% AA in the right situations. Death due to alcohol, time, and the like is what you need to worry about, if anything.