Trouble hitting FG

[ekacnap]

Hello fellow homebrewers,

I've got a problem. I'm having trouble hitting my final gravities. They're fermented in a basement that's usually 65-74 degrees. Could this be the cause of missing my final gravity by 10-20 points? I used to use just one smack pack but even after I switched to using two for each batch the problem has persisted.

Some examples: Creme Ale starting at 1056, ending at 1030.
Saison starting at 1054, ending at 1029
Honey brown starting at 1052, ending at 1024
Irish Red starting at 1042, ending at 1022

Thanks!

 

[biestie]

The temp in your basement is on the high side if anything, so that wouldn't typically lead to high FGs.

Before I started making starters, my FGs were on the high side, but not that high.

Are you aerating? That's even more important if you're doing full wort boils.

If I were you, I'd make my next beer with dry yeast, and see if the problem persists. If not, than it's likely due to underpitching/underaerating (I suspect it's both).

 

[pabloj13]

Need to know much more. All-grain? Mash temp? Recipe?

 

[ekacnap]

I do aerate, just by shaking for a few minutes before fermentation. I brewed a black IPA and used dry yeast a few weeks ago, which started at 1067 and ended at 1024.

I just ordered a stir plate and flask, so hopefully making a starter will help too.

I do all grain, my mash temps are usually 154-157. Recipes used are mostly AG kits from NB.

Thanks for your help!

 

[pabloj13]

I do aerate, just by shaking for a few minutes before fermentation. I brewed a black IPA and used dry yeast a few weeks ago, which started at 1067 and ended at 1024.

I just ordered a stir plate and flask, so hopefully making a starter will help too.

I do all grain, my mash temps are usually 154-157. Recipes used are mostly AG kits from NB.

Thanks for your help!

Are you sure of your thermometer? Have you calibrated it?

 

[1Mainebrew]

I think your mash temps are too high. Try dropping that down to 152 or so and that should lighten the load on the yeasties ability to get at some small chain sugars.

 

[phoenixs4r]

Something is wrong. Probably your hydrometer. I've pitched 3 month old smack packs in 1.087 beers and they came out fine. Winning competition fine? Probably not but I and my friends drank them, enjoyed them and got wasted, which is ultimately the point.

What temperature are you taking OG, what temperature are you taking FG? How long in between?

What does your hydrometer read in 60° tap water? Yes your supposed to used distilled to get a real accurate number of your hydrometer, I don't care we just need a baseline.

 

[ekacnap]

I haven't calibrated my thermometer, so maybe that could be it. It seems pretty accurate though, the only way we've tested it was to leave it in water that we were bringing to a boil. It said 212 right when it started to boil.

I tried using a little lower temp (154-152) on the black IPA I brewed today, hopefully that will help.

I use a refractometer to take my readings. We calibrated it with distilled water. I checked the reading of our cream ale refractometer reading against our hydrometer reading and they were about 5 points off. Maybe I'll try to re-calibrate.

 

[1Mainebrew]

How much crystal malt are you using in your recipes?

 

[mvcorliss]

Are you using your refractometer for both your SG AND your FG? Cuz you can't.
Once fermentation starts and alcohol is produced the refractometer is no longer accurate. It is designed to measure sugar content in WATER. Alcohol is much less dense and throws off the readings. You need to used a hydrometer .... or, plug your fermentation readings into a spreadsheet that will (approximately) correct for the alcohol.
Here's a link to someone who has been working on tweaking his calculation for awhile.

http://seanterrill.com/2011/04/07/refractometer-fg-results/

Scroll down to just before the comments section for the spreadsheet link.

Some people don't believe that these calculations are accurate enough. I think this one is close enough to offset that PIA that I find using a hydrometer vs the ease of a refractometer. This calculation is easily within .001 SG point the vast majority of time. Not all of the formulas out there are even close.

 

[pabloj13]

Are you using your refractometer for both your SG AND your FG? Cuz you can't.
Once fermentation starts and alcohol is produced the refractometer is no longer accurate. It is designed to measure sugar content in WATER. Alcohol is much less dense and throws off the readings. You need to used a hydrometer .... or, plug your fermentation readings into a spreadsheet that will (approximately) correct for the alcohol.
Here's a link to someone who has been working on tweaking his calculation for awhile.

http://seanterrill.com/2011/04/07/refractometer-fg-results/

Scroll down to just before the comments section for the spreadsheet link.

Some people don't believe that these calculations are accurate enough. I think this one is close enough to offset that PIA that I find using a hydrometer vs the ease of a refractometer. This calculation is easily within .001 SG point the vast majority of time. Not all of the formulas out there are even close.

I bet this is it.

 

[ekacnap]

Are you using your refractometer for both your SG AND your FG? Cuz you can't.
Once fermentation starts and alcohol is produced the refractometer is no longer accurate. It is designed to measure sugar content in WATER. Alcohol is much less dense and throws off the readings. You need to used a hydrometer .... or, plug your fermentation readings into a spreadsheet that will (approximately) correct for the alcohol.
Here's a link to someone who has been working on tweaking his calculation for awhile.

http://seanterrill.com/2011/04/07/refractometer-fg-results/

Scroll down to just before the comments section for the spreadsheet link.

Some people don't believe that these calculations are accurate enough. I think this one is close enough to offset that PIA that I find using a hydrometer vs the ease of a refractometer. This calculation is easily within .001 SG point the vast majority of time. Not all of the formulas out there are even close.

That's probably it! I kind of just assumed it worked for both, but I guess I never checked for sure.

Thanks so much for your help! I plugged some readings in and it looks much better. Not perfect, but I think the only thing between me and getting a low FG I'm looking for is making a starter.

And 1Mainbrew, not much Crystal was used. Maybe a fourth of a pound in 2-3 recipes. Is that known for creating sugars that are stubborn when fermenting?

 

[pabloj13]

That's probably it! I kind of just assumed it worked for both, but I guess I never checked for sure.

Thanks so much for your help! I plugged some readings in and it looks much better. Not perfect, but I think the only thing between me and getting a low FG I'm looking for is making a starter.

And 1Mainbrew, not much Crystal was used. Maybe a fourth of a pound in 2-3 recipes. Is that known for creating sugars that are stubborn when fermenting?

They would also taste insanely sweet at those FGs.

 

[1Mainebrew]

Too much crystal will lead to high FG. CM's contain sugars that are not fermentable. They become cloying at too high of percentages of your grain profile.

 

[ekacnap]

Yes, I thought they should have been sweeter too at those gravities, but I figured maybe the hops balanced it out if the readings were right.

Thanks, I'll try to not use too much CM in the future, that's a good bit of knowledge to have.