Attenuation question

[Whiskey]

Alright I'm on my second batch, which has been in the fermenter going on 14 days. I checked the FG which read 1.020 (the OG was 1.060). Doing the math I'm getting about %66 attenuation, does this sound right? I used a WY1338 smack pack in a chocolate porter. From what I can find 1338 has a apparent attenuation of %69.

It's going to stay in the fermenter a couple more days irregardless so I can take a second reading, I just wanted a second opinion.

 

[Evan!]

A couple things we need before we can answer your question:

• Fermenting temps
• Starter: Y/N?
• Oxygenation: Y/N?
• Recipe and mash temps if applicable

If you added any adjuncts (like chocolate) that can affect your FG. 66% for a 69% apparent yeast isn't bad...and if you mashed high or you used adjuncts, it might be just about right. Did you oxygenate your wort in any way? Did you make a yeast starter?

 

[david_42]

You've got the math correct and it's probably done or close to done.

 

[Whiskey]

A couple things we need before we can answer your question:

• Fermenting temps
• Starter: Y/N?
• Oxygenation: Y/N?
• Recipe and mash temps if applicable

If you added any adjuncts (like chocolate) that can affect your FG. 66% for a 69% apparent yeast isn't bad...and if you mashed high or you used adjuncts, it might be just about right. Did you oxygenate your wort in any way? Did you make a yeast starter?

Fermentation temps have been at or near 68F
No starter just the WY1338 smack pack.
No oxygenation other than shaking the hell out of the wort before pitching yeast.

Recipe

6.6 Lbs Light DME
2 lbs 60L Crystal
1/2 lbs chocolate malt,
1/2 lbs Caramel Pils
1/2 lbs Debitterized Black Barley

1 oz Northern Brewer Hops at boil
1tsp Irish Moss @ 40 min
24 Tbsp Plain Chocolate Powder @ 50 min (I used Ghirardelli unsweetened)
WY 1338 European Ale

The grain was steeped in 2 gallons of distilled water @ 155 for 30 minutes drained then rinsed with 1 gallon of hot water. Boil volume at the end of the boil was right at 3 gallons. Yeast was pitched at 65F.

I wasn't worried about a stuck fermentation, just whether I was figuring the attenuation correctly or not. I'm going to check for FG on Thursday and then hopefully rack to secondary.

That WY1338 leaves an impressively thick krausen, it looks like chocolate mousse.

 

[TheJadedDog]

66% sounds about right to me for an extract brew. Most extracts have a bunch of unfermentable sugars in them so they tend not to attenuate much above 65%.

 

[Whiskey]

Outstanding, thanks.

 

[mdowns63]

What is the math exactly for figuring % attenuation? I am about at the same step in my first batch and would like to figure this out. Thanks!

 

[Got Trub?]

Fermentation temps have been at or near 68F
No starter just the WY1338 smack pack.
No oxygenation other than shaking the hell out of the wort before pitching yeast.

Recipe

6.6 Lbs Light DME
2 lbs 60L Crystal
1/2 lbs chocolate malt,
1/2 lbs Caramel Pils
1/2 lbs Debitterized Black Barley

1 oz Northern Brewer Hops at boil
1tsp Irish Moss @ 40 min
24 Tbsp Plain Chocolate Powder @ 50 min (I used Ghirardelli unsweetened)
WY 1338 European Ale

The grain was steeped in 2 gallons of distilled water @ 155 for 30 minutes drained then rinsed with 1 gallon of hot water. Boil volume at the end of the boil was right at 3 gallons. Yeast was pitched at 65F.

I wasn't worried about a stuck fermentation, just whether I was figuring the attenuation correctly or not. I'm going to check for FG on Thursday and then hopefully rack to secondary.

That WY1338 leaves an impressively thick krausen, it looks like chocolate mousse.

Considering you didn't use a starter and did not vigourously aerate your beer you were pretty damn close to expected attenuation. Invest in a cheap "deep" tank aquarium pump and a sterile filter and you can reach oxygen saturation in your wort in about 30 minutes. Learn to make starters - they are easy and you can make a single (expensive) smack pack go a long way. If you do those two things you should hit the higher attenuation limit for a given yeast strain.

GT

 

[DeathBrewer]

What is the math exactly for figuring % attenuation? I am about at the same step in my first batch and would like to figure this out. Thanks!

OG = Original Gravity
FG = Final Gravity

(OG-FG)/(OG-1) [*100 will give you percentage]

 

[beertard]

It's going to stay in the fermenter a couple more days irregardless so I can take a second reading, I just wanted a second opinion.

Just so you know, "irregardless" is not a word. If you think about it, it makes no sense.

 

[Whiskey]

Just so you know, "irregardless" is not a word. If you think about it, it makes no sense.

Not trying to start a debate or anything....

irregardless

Main Entry:
ir·re·gard·less Listen to the pronunciation of irregardless
Pronunciation:
\ˌir-i-ˈgärd-ləs\
Function:
adverb
Etymology:
probably blend of irrespective and regardless
Date:
circa 1912

nonstandard : regardless
usage Irregardless originated in dialectal American speech in the early 20th century. Its fairly widespread use in speech called it to the attention of usage commentators as early as 1927. The most frequently repeated remark about it is that “there is no such word.” There is such a word, however. It is still used primarily in speech, although it can be found from time to time in edited prose. Its reputation has not risen over the years, and it is still a long way from general acceptance. Use regardless instead.

Improper, maybe, mainstream, not really, definitely nonstandard, but it is a word.

Back to the subject....

After 2 more days, the FG is still at 1.020 so I went ahead and racked to secondary. This one was especially fun as I had about 2 inches of trub on the bottom and a thick mousse like head, which never settled out. I plan on leaving it in the secondary for the full two weeks (2 weeks primary, 2 weeks secondary).

Again thanks for all the help guys.