Consistently low FG

[brewser7]

I've been experiencing consistently low final gravity with my all grain beers (5 batches to date) Most of the recipes have called for 1.012 or so but my beers have been finishing at 1.005-1.006. Once I thought I mashed too high (158-160) so the next time I dropped to 152 but still the same problem. I'm still trying to figure out my efficiency so I didn't worry about it too much at first because i wasnt hitting any of my numbers. I was spot on with this last batch so I'm curious now.


The beer tastes just fine but I want to be able to do it "right". Any thoughts, suggestions? Is this a "first day material" question or will it require an in depth analysis of my process, system, water etc? Hopefully it's something simple.

I'm using a hydrometer to take my readings and using wyeast 1056 fermenting at 68 degrees, + or - 1 degree

Thanks

 

[helibrewer]

That strain does attenuate pretty well...are you sure your mash temps are accurate (thermo is calibrated/accurate)? Low temps would give you a more fermentable wort.

Is this a single infusion mash? Are the OG's what you have expected?

 

[brewser7]

I tested the MT thermometer against another and they both read the same.

The first few batches had a lower OG than planned so I didn't worry about missing the FG as much. This last OG was right on the nose and still finished low. That's what made me think it could be me screwing something up. The beers have tasted great so I'm not complaining, just hoping to understand what's going on a bit better.

 

[veritas524]

Test both your thermometers at 32 deg using ice water and 212 via boiling. If either are off check them in your mash range. If you want to raise your fg, try mashing a few degrees higher than what you have been. Also, check your hydrometer with distilled water and make sure it reads 1.000 on the nuts at the appropriate temp.

 

[BobC]

Any FG a program, recipe or calculation comes up with is purely guess work since they have no way of calculating your brewing process. The only time you should worry about your FG is when it doesn't seem to get low enough. The only time you want to mess with your mash temperature, assuming you only want to do a single temperature mash, is if you want to make a sweet beer, like a Belgium. Them you would mash at a higher temperature to get more complex sugar chains that are harder for yeast to break up into alcohol. In short a low FG is nothing to worry about.

 

[bumstigedy]

Maybe you have an infection and the bugs continue to ferment the beer to a lower gravity. Have you checked your hydrometer? Maybe your hydrometer is reading low.

 

[Pommy]

Maybe you have an infection and the bugs continue to ferment the beer to a lower gravity. Have you checked your hydrometer? Maybe your hydrometer is reading low.

worst case scenario this is possible, check everything else first, I found my thrermometer to be off by around 2C so I just adjust for that now and problem fixed

 

[hercher]

What types of beers are you brewing? Can you post a sample grain bill?

 

[brewser7]

I'll test thermometer and hydrometer again tonight to see how they look. I'm on my phone so I'll have to get the recipes later but the three main offenders were 2 blondes and an Irish red.

Thanks for the suggestions

 

[Gduck]

While you may be finishing lower than expected, the one thing you should be happy about is your FG seem to be consistant, and that is important. Using e same yeast and getting the same range of FG, especially when the beer tastes good, sounds like you have a sound process. There's nothing wrong with trying to figure out why you're getting lower numbers as it helps you understand what is going on better, but I wouldn't worry too much over chasing numbers so long as you keep making tasty brew!

 

[RM-MN]

My LHBS has glass lab grade thermometer pretty cheap. When my beers started coming out with a really low OG I invested in one and found that my main thermometer was reading 4 degrees high which meant that I mashed 4 degrees lower than I thought. My Irish red that should have finished at 1.012 to 1.016 actually finished at 1.002 which was not what I wanted and I don't care much for the change in flavor.

 

[JuanKenobi]

I'd be willing to bet that this a hydrometer calibration thing. You say that the OG of the first few batches was also low, and that the most recent one you hit dead on. I bet those first few were closer to target and that the most recent one overshot and that your finished gravity readings were really closer to expectation. Any FG down in the 1.005 - 1.006 range is VERY low and would require extremely attenuative yeast and/or VERY low mash temps (under 150). Plus if the beers taste great to you and are not too thin or dry then it seems unlikely to me that they are drying out that much.

I have had many hydrometers and only 1 of them has ever calibrated dead on.

 

[RandomBeerGuy]

What I find that the lower the FG the better the brew. I like to take them as low as they can. So I know yeast have munched up that sugar. I don't see a low FG a problem. Some people have hard time getting under 1.020.

 

[SwampassJ]

Try a different yeast. What was your grain bill for these beers that finished low? I stopped using 05/1056 because of how much it tends to attenuate. Last beer I used it in was a Wheat and it went from 1.056 to 1.008 and made for a nice crisp finish and that was with a 152ish mash temp. I can only imagine how much lower it would have dropped had I missed and hit 148 like I did on the batch before.