Noob problems - missing FG

[Buccaneer]

I've fermented two batches of extract-based brews now and in both instances I've hit the OG pretty much bang on, but been short of the FG.

My first brew was an amber ale from Everwood, fermented with US-05. I came up a bit short on this one (hit 1.015 instead of 1.012). The research I did at the time suggested maybe I didn't have enough aeration.

My second brew was an IPA, again from Everwood, again fermented with US-05. I made sure to pour back and forth between the kettle and fermentation bucket a lot. I came up a little bit shorter this time around - 1.020 instead of 1.015.

In both cases, I rehydrated the yeast in about 1 cup of sterilized water (at about 20-23C) for about 30 minutes before pitching. Fermentation temps were 20-22C throughout the entire process.

For both batches, fermentation was very vigorous after about 24 hours and started dying down after about 4 days. For the first batch, fermentation stopped on day 5. For the second batch, things moved along for a couple extra days, stopping on day 7.

I'm not really sure where to go from here. Any thoughts or suggestions?

[RubberToe]

Do you have another hydrometer to check against? It's also possible it's just off. I have one that reads high by a few points.

Sent from the brew timer.

[mr x]

Could be the extract. How are you figuring your og?

Sent from my Nexus 4 using Tapatalk 4

[GuingesRock]

How long after pitching are you checking your FG? Have you checked again to see if it came down further? You don't need to aerate with dry yeast. Does the beer taste sweet or dry? Is it a high gravity beer? If so, you could double up on the yeast.

[LeafMan66_67]

You mentioned fermentation stopped at day 5 and day 7. Did you keep measuring for days after that for comparison?

[Joeg]

Just throwing this out there where you say this is a "noob" problem I always make sure I temperature correct my hydrometer readings with http://hbd.org/cgi-bin/recipator/recipa ... meter.html because mine is calibrated at 60 F.

[Buccaneer]

Do you have another hydrometer to check against? It's also possible it's just off. I have one that reads high by a few points.

I don't. I should look into that. However, the OG seems to be accurate.

Could be the extract. How are you figuring your og?

I'm taking a sample right before I pitch the yeast.

How long after pitching are you checking your FG? Have you checked again to see if it came down further? You don't need to aerate with dry yeast. Does the beer taste sweet or dry? Is it a high gravity beer? If so, you could double up on the yeast.

I typically leave the beer in the fermenter for almost 3 weeks. Then I take the FG sample right before kegging.

The first batch was pretty sweet. I'd say the latest one is less sweet, but still there. Dave from Everwood also suggested I double up on yeast.

You mentioned fermentation stopped at day 5 and day 7. Did you keep measuring for days after that for comparison?

The only time I've opened up the fermenter is pretty much just before I keg it, so I've never taken measurements along the way. I was thinking of doing that with my next batch. The only way I judge fermentation is by looking at activity in the airlock. I have taken that out to look at the krausen for both batches. I've been too nervous to open any more than that.

[mr x]

Sorry, I meant FG, and not how you are measuring it, but how are you deciding what it should be?

Sent from my Nexus 4 using Tapatalk 4

[saosborne]

if you're measuring your FG by airlock activity ,don't. leave it longer than suggested. see if the SG goes lower. currently drinking a cda that, according to the airlock finished at 1.020, left it for 10 days FG is 1.011. what are you fermenting in plastic or glass? how much head space? these all play into airlock activity.

[GasMD30]

3 weeks is a good amount of time. If it was all grain I'd say you mashed at too high of a temperature....

[saosborne]

I might mention that over those 10 days i never saw any airlock activity in addition to being in glass. my advise is transfer it to a secondary( if you haent already), wait a week, see if the SG drops.

[RubberToe]

If you had a vigorous fermentation at the temperatures you say, I doubt doubling the yeast will help. IMO it would be a waste to throw another pack of US-05 at a middle of the road gravity brew.

Regarding aeration, assuming your yeast pitch is big enough you really don't _need_ to aerate using dry yeast as they contain the lipids needed for replication. Having said that, I usually aerate anyways, and more so on higher gravity brews.

The fermentability of LME and DME is always suspect.

If you don't normally transfer to secondary, I wouldn't. Removing the beer from the bulk of the yeast isn't going to help it finish any lower.

You might want to rouse the yeast somehow, either by shaking the carboy or stirring it up with a sanitised spoon (try not to aerate).

It's worth a little effort trying to fix this brew but don't beat yourself up about it.

If you bottle, bottling a beer that's not finished may be problematic. If you keg, keg / drink it and move on.

That's all I got now. Cheers and good luck.

[Buccaneer]

As I said, for both batches, I let the beer sit in the fermenter for just shy of 3 weeks (I think it just happened to be 19 days for each batch - purely coincidence). I didn't transfer either to secondary.

I have run across the idea of stirring up the yeast when things start to slow down while researching this, and now that it's being mentioned here, I think I'll give it a try for the next batch (second one is already in the keg). I ferment in a plastic bucket and I've been hesitant to open that up until everything is "finished" (based purely on time). But if I'm going to open it to potentially stir it, then I may as well take an SG reading (perhaps even a couple of times during the 2nd week). And I should probably crack it early on to actually SEE how fermentation is progressing.

[adams81]

Could some of your sugars be caramelizing in the boil? When and how are you adding your extract?

[Buccaneer]

I get the water to boiling, then I take it off the heat, and slowly add in the extract, making sure I stir it well. Then I put it back on the heat and bring to boiling again, stirring occasionally.

[GuingesRock]

Where did the predicted FG come from? Who calculated it? The predicted FG could be wrong.

The hydrometer could still easily be the problem. I have 4, maybe 3 now (broke one, they quite often get broken and it's an idea to have a spare). only two of them agreed with each other. I have my favorite one that I use because it more often gives me the figures that I want. Your hydrometer gives you the OG figure you are looking for, but that doesn't mean the hydrometer is accurate. It could be way off on the OG as well. Like my hydrometer could be. I believe in it because it often gives me the figures I'm looking for. Hydrometers are notoriously inaccurate, like most thermometers.

You could buy another couple of hydrometers and use the one that gives you the results you want to have. That's what I did any way.

Apparently (Sandy told me at the RB firkin Wednesday) you can get separate hydrometers, one specifically designed for measuring OG and one for measuring FG. Just more sensitive within the two ranges, and not designed to measure everything from engine oil to neat spirits LOL. I think that's a great idea. I don't know where you get them though.

[GAM]

Apparently (Sandy told me at the RB firkin Wednesday) you can get separate hydrometers, one specifically designed for measuring OG and one for measuring FG. Just more sensitive within the two ranges, and not designed to measure everything from engine oil to neat spirits LOL. I think that's a great idea. I don't know where you get them though.

Greg has a set of three that provide more accurate measurments. I have one FG one and a regular one for all else.

Sandy

[Buccaneer]

Where did the predicted FG come from? Who calculated it? The predicted FG could be wrong.

Dave gave me the numbers, since they are his kits.

Apparently (Sandy told me at the RB firkin Wednesday) you can get separate hydrometers, one specifically designed for measuring OG and one for measuring FG. Just more sensitive within the two ranges, and not designed to measure everything from engine oil to neat spirits LOL. I think that's a great idea. I don't know where you get them though.

Apparently (Sandy told me at the RB firkin Wednesday) you can get separate hydrometers, one specifically designed for measuring OG and one for measuring FG. Just more sensitive within the two ranges, and not designed to measure everything from engine oil to neat spirits LOL. I think that's a great idea. I don't know where you get them though.

Greg has a set of three that provide more accurate measurments. I have one FG one and a regular one for all else.

Sandy

Sounds like something I should investigate further. I did manage to find a second hydrometer (my dad used to try to make wine years ago) and both came up with the same OG for the batch I just brewed.

[AllanMar]

The seperate range ones are way better. Much easier to read and more accurate. Winemakeri (online/sackville) also sells em