FG vs time in bucket

[duskb]

I'm having a tough time understanding the concept of FG. Now that I'm brewing big IPAs I'm looking to obtain a sweeter beer, which implies that the beer needs to finish higher, but I'm also trying to figure out how to manage this without ending fermentation too soon or drying the beer up. The last several batches ended up below FG in less than 12 days (at 1.01.) They seem to finish too low too fast. To rectify this I've started pulling the beer off the yeast cake earlier at 10 days because it was already below the FG. But then, the most recent beer I did this to has a meaty taste to it and Im not really into it. I can't help but think I'm missing something. Obviously I want the beer to "finish" but I also want to keep some sweetness left in it. How does one manage to accomplish a finished beer without sucking all of the sweetness out of it?

 

[day_trippr]

How does one manage to accomplish a finished beer without sucking all of the sweetness out of it?

By the grain bill, and in consideration of the expected attenuation of the particular yeast strain used (more aggressive = more dextrins in the grist).
A recipe calculator is a huge help in calculating - and adjusting - expected FG.

btw, wrt to your FG readings, rounding to one decimal place doesn't tell us enough.
There's an obvious difference in body (and potential residual sweetness) between a 1.010 beer and a 1.019.
I like my IPAs to finish around 1.015 - right in the middle.

Also, are you using a pitch rate calculator? A big time over-pitch - which includes reusing an entire yeast cake from one batch for the next - can easily dry the heck out of a brew...

Cheers!

 

[flars]

Using a yeast that attenuates less will leave a residual sweetness without the risk of a fermentation slowly finishing in the bottle.

 

[worlddivides]

There are several factors:
1. The biggest factor, in my opinion, is the yeast that you use. As just an example, you could have the exact same wort - half in one fermenter and half in the other - and ferment half with a high attenuating yeast (some type of Californian yeast, for example) and ferment half with a low attenuating yeast (some type of English yeast, for example) and the one half ends up at 1.011 and the other half ends up at 1.019 (for example).
2. How fermentable your wort is. Obviously if you mash higher, the wort will have more complex sugars, which are harder to ferment or impossible to ferment (with brewers' yeast, at least). In general, mashing lower will get you a dryer beer and mashing higher will get you a maltier beer.
3. You could also add unfermentable sugars like maltodextrin directly to the wort. I haven't had many IPAs that add unfermentable sugars, but I have had a few, I guess.
4. By your grain bill.

Also, you should never try to get a higher finishing gravity by pulling the beer early. The only way that will succeed is if you pasteurize your beer immediately after you pull it. Otherwise, you could get bottle bombs because if the yeast isn't done and you bottle it (without pasteurizing), it WILL keep fermenting.

 

[Magnus314]

Crystal/caramel malt.

 

[Denny]

I've found that the attenuation rating of a yeast doesn't make a lot of difference. It's simply a way of comparing one yeast to another, not necessarily an indication of the attenuation you can expect to get. Using the same yeast, I can get from 65-85% attenuation by varying the grist. You do not want to try to control sweetness by underfermenting. You want to get eh beer you're looking for once it's completely fermented out. You can do that by manipulating the grist, cutting back on hopping, or cutting back on sulfate in your water.

 

[stratslinger]

One misconception I think OP is expressing is just exactly what FG is.

Final Gravity is the point at which fermentation is complete and stable, full stop. It is impossible for a beer to ferment lower than FG. If it's still fermenting, it hasn't reached FG.

_Target_ FG is the Final Gravity that you're trying to hit. You can have beers underattenuate (leading to a higher FG than targeted) or overattenuate (leading to a lower FG than targeted).

This is an important distinction - mostly because, as folks have pointed out, if you're bottling and just go straight to bottling at your _Target FG_ instead of making sure you're at your actual FG, you could set yourself up for a potentially dangerous situation (a la bottle bombs).

So - OP, how are you calculating your target FG? Are you using some recipe software, or just going by the target listed in a kit? Are you brewing extract or all grain? If all grain, you have a lot of options to tweak your recipe to arrive at a higher FG (or just a sweeter tasting beer - I have a 1.014 beer that's actually very sweet, and have had beers at the same gravity that taste very dry). Try mashing higher, increasing (just by a little at first!) the amount of crystal/caramel malts in your recipe, using dextrine or lactose (actually, lactose can work for extract too, though the sweetness it adds tends to lend more towards sweet stouts than IPA's).

Heck - if you're talking IPA's, try just backing off a little on your 60 minute hop addition. Less bitterness can lead to greater perceived sweetness - a LOT of the New England IPA's that are all the rage lately use very small or no bittering addition, leading to some pretty sweet beers.

 

[dmtaylor]

I think selection of yeast is the number one most important factor. If you're using US-05 or Nottingham ale yeast or their relatives, you're going to get high attenuation every time. Try different yeasts and look for one with lower attenuation ratings. Also like Denny indicates, the comparison between ratings is most important but the actual numbers they give you are often wrong. Just use them to compare and select based on that.

Recipe also matters. Simple sugars will reduce FG while crystal malts will increase it. These are just a couple of examples. With experience you'll learn much more.

 

[Denny]

I think selection of yeast is the number one most important factor. If you're using US-05 or Nottingham ale yeast or their relatives, you're going to get high attenuation every time. Try different yeasts and look for one with lower attenuation ratings. Also like Denny indicates, the comparison between ratings is most important but the actual numbers they give you are often wrong. Just use them to compare and select based on that.

Recipe also matters. Simple sugars will reduce FG while crystal malts will increase it. These are just a couple of examples. With experience you'll learn much more.

Not necessarily, Dave. You may get higher attenuation than another strain, but you can reduce attenuation even with 05 by manipulating your recipe.

 

[dmtaylor]

True. Recipe also matters.

 

[duskb]

Thanks for the replies. I'm not thrilled about the wording of my original post but the statement above "never try to get a higher finishing gravity by pulling the beer early" answers my question. I was not aware of this until now and it probably explains why this beer tastes 'off'. I yanked it off too early. Maybe it will continue to age and get better, maybe not. It's in a keg so of course there's plenty of room for fermentation to continue.

FWIW, Most of the beers I have been having trouble with (lately) were extract or AG recipes that were pre-made by Northern Brewer. We followed the recipe in both cases to the letter and should have gotten acceptable results. The wort tastes fine, and it tastes fine in the bucket, but it's pretty clear the beer finishes fast and below what the "target" gravity should be. I've been using 05 in all cases. Maybe the sweetness is what it should be and I'm just expecting something sweeter than the recipe actually provides. I understand the idea of mashing to control sweetness but I didn't realize crystal malts could help increase sweetness without adding more fuel to the fire. I never added two and two together.

I have made a few small batch partial mash homegrown recipes from the second runnings of all the AG beers and have noticed the beers all taste great but need to be a tad sweeter. In the future in these experimental recipes I'll find some extra unfermentables to help ensure sweetness, especially when dumping fruit on top of it, which always seems to dry it up.

 

[dmtaylor]

I've been using 05 in all cases.

I also love to say I told you so.

You may have better luck with most other yeasts. US-05 is a relatively very high attenuator. Try BRY-97 or S-04 or something else.