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Final Gravity and Alcohol content

Discussion in 'Homebrewing' started by TastyAdventure, Mar 3, 2013.

  1. SKIP to the BOTTOM for my 2 questions. details below in case you care.


    The recipe I followed:

    Belgian Dubbel
    Grains:
    4 oz aromatic
    4 oz chocolate
    6 oz special B
    8 oz carapils

    Hops 2 oz kent golding (45 min) 1 oz Saaz (15 min)

    Yeast. THIS is where it gets hairy. I pitched Wyeast Bel. Abbey II originally that had been sitting out of the fridge for 5 days. After I pitched I learned I was supposed to keep it in the fridge. anyways, after 2 days there was no action in the airlock, so i repitched some new yeast and saw some action in the airlock for somewhere in between 1.5 - 2 days.

    My original Gravity was 1.070 just like the recipe says.

    After 2 1/2 weeks of primary I measured and the FG was 1.020, whereas the recipe says it should be 1.015 - 1.017. After reading around on the internet I decided I should just go ahead and rack it in secondary.

    So,

    1) Considering the recipe says the ABV will be 7.2%, and that my FG was .003 off, what ABV can I expect?

    2) is there anything I can do (add sugar, yeast, etc) to secondary to bring it closer to 1.017?


    Thanks for reading.
     
  2. OP P.S. I've also heard of people shaking primary/secondary containers to get some action going in there. is that legit?
     
  3. VikeMan

    VikeMan Champion (750) Pennsylvania Jul 12, 2009

    Your ABV will be slightly lower. Here's one of many ABV calculators...

    http://www.brewersfriend.com/abv-calculator/

    I suspect the yeast you have already pitched (twice) are going to take this beer's attenuation as far as it's going to go. Adding sugar would boost ABV, but it would not reduce the final gravity. Gravity comes from residual sugars that do not ferment, not from sugars that do. More residual sugars = higher gravity.
     
  4. VikeMan

    VikeMan Champion (750) Pennsylvania Jul 12, 2009

    Gently Rousing the yeast (not shaking, which would cause more 02 to go into your beer, which you don't want at this point) can sometimes unstick a stuck fermentation. But unless you already have a yeast cake forming in the secondary, there's nothing to rouse. I would just keep the wort/beer in the yeast's recommended temperature range and let the yeast finish their job. By the way, you really didn't need a secondary for this beer, and racking before attenuation was done may well be partially responsible for the slowdown (if there actually is one).
     
  5. thanks a lot VikeMan. What kind/amount of sugar should I add to it in secondary?
     
  6. VikeMan

    VikeMan Champion (750) Pennsylvania Jul 12, 2009

    I wouldn't add any personally. You don't know where your FG and ABV are going to end up yet.

    Edit: But if you do, each pound of table sugar added to a 5 gallon batch should add about 1.2% ABV.
     
  7. utahbeerdude

    utahbeerdude Savant (440) Utah May 2, 2006

    1.070 --> 1.020 = ~6.6% abv. Adding sugar to the secondary may raise the abv, but it won't lower the FG. If the yeast are weak, it may not even raise the abv. Personally, I don't think I wouldn't add any sugar. To decide this I guess I would taste the beer and see whether I thought added alcohol would improve it.

    You may be able to lower the FG by making a starter and pitching it while active. To do this you could simply go with a dry, neutral ale yeast such as US-05. At this point you have pretty much gotten the character you are going to get from your Belgian yeast.

    Adding some fresh yeast will also help with carbonation in the bottle, if, indeed, your Belgian yeast is weak. It may simply be that (pretty much) any yeast will not lower the FG any more; i.e., all the fermentables may have been consumed.

    As the beer has only been fermenting 2 1/2 weeks, it may also be that the yeast isn't quite finished doing its job. Simply waiting a week and taking another gravity reading will tell you whether this is the case or not.
     
  8. I disagree. A sugar addition is a bad idea :p Seriously though, this is an obvious underpitching situation. Adding more yeast or more sugar will not dry out this beer.

    It is what it is. That said, it is still beer.
     
  9. How does the beer taste? Do think you can taste a 0.5% ABV difference?

    RDWHAHB!

    Edit - would you want to drop the ABV if the FG came out to 1.010? Just saying it is not worth the effort to bump the ABV.
     
  10. premierpro

    premierpro Savant (315) Michigan Mar 21, 2009

    Well I do not see what he used for his base grains or mash temp witch can effect F.G. I would not touch this beer unless it tastes too sweet. I have had beer finish higher then expected pitching on a yeast cake. Somtimes things do not go as planed and thats where plan "B" comes in.
     
  11. i guess now my main concern is: what if I add the priming sugar and bottle, and there's not enough yeast to bring about carbonation?
    I'm thinking of adding a half pack of yeast and some sugar to it, letting it sit for a week more in secondary, and then bottling.

    Or should i just quit worrying and see what happens??
     
  12. VikeMan

    VikeMan Champion (750) Pennsylvania Jul 12, 2009

    If you're going to add some insurance yeast, just do it at bottling time, along with your priming sugar. And a half pack would be way more than enough.

    That would be my first inclination.
     
  13. thanks Vikeman, that was most helpful. I'll add a pinch of yeast at bottling time.
     

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