You Cant Explain It So Dont Even Try!!

[docmoran]

Ok, so you looked - now have a try. Although a noob I know enough about every conceivable variable involved in fermentation yet just dont get why I miss my FGs so consistently. I am always off by .02 - .03 in FGs and thats with Oxygenation/two liquid yeast vials/strict temp control etc!! I am ok with this as my beer is GOOD in my humble opinion -- just dont want to miss the full deal. Any comments on this PERPLEXING problem??? thanks, doc

 

[GilaMinumBeer]

The beer gods are tormenting you.

 

[farmbrewernw]

I wouldn't worry about it too much, being off by a few points isn't a big deal usually.

 

[chumprock]

I cant explain it, but maybe the wiki can shed some light on the subject:

Understanding Attenuation - Home Brewing Wiki

 

[Evan!]

Are you doing all-grain or partial mashes? If so, your thermometer might be off, and you could be mashing too high. Use ice water to calibrate your thermometer.

If you're doing extract beers, then you might try a different brand of extract. I know for a fact, for instance, that Laaglander DME is not very fermentable, relatively speaking.

 

[rsmith179]

I would also check your hydrometer to make sure that it is reading properly. Test it out in some distilled water. You should have a hydro reading of exactly 1.000. It is very possible that the hydrometer is not calibrated quite correctly resulting in a slightly off gravity reading. Also, check the temp of the sample you are taking and make sure that you have adjusted the gravity accordingly for the temperature of the sample.

 

[Revvy]

I wouldn't worry about it too much, being off by a few points isn't a big deal usually.

Yeah, that's my feeling as well...especially for extract..if you are that close to your fg then all is well....

 

[JuanKenobi]

I know it's super obvious, but hydrometer calibration would be my first stop. I'm sure you've thought about that. At finished gravity ranges I doubt this would make much of a difference, but there's a very interesting article on hydrometer calibration on HoneyCreek Vineyard's website where the author had 2 hydrometers that both read 1.000 in 60* water, but one was off at higher gravities: Calibrate Your Hydrometer

If you're brewing with extract, I'd think about that. I have brewed a lot with Munton's LME with similar results to yours. I've had better results with DME and even better with PM batches.

EDIT: I'm way to slow

 

[SnickASaurusRex]

It sounds like a case of system variation. For the most part the FG is a predicted number, and 2 - 3 points is a very normal margin of error. The biggest factor here is variation in malts or malt extracts. and to a small degree a variation in technique.

The best way to overcome these system specific variations, is to brew the same (exact same) recipe several times using the same procedure. If your numbers are always the same then you know the yeast are fully attenuating. If the numbers are varying then you know something is up.

Once you know that the yeast are fully attenuating, you can begin to change variables in your system. mash temp and time for one. replace a portion of the malt with a high fermentable, honey or sugar etc.. Then you can make the necessary changes to your recipe to make it work on your system.

I call this process "dialing in". I think I have seen other people use that term too.

 

[GilaMinumBeer]

I think it's entirley possible you are hitting your targets and what you have is a condition of the error tolerance inherent in the tool.

I forget what exactly the error tolerance is on most hydro's.

 

[Boerderij_Kabouter]

I am always off by .02 - .03 in FGs and thats with Oxygenation/two liquid yeast vials/strict temp control etc!!

Do you mean 0.02 - 0.03 off? because that would be 20-30 gravity points and a big deal. if it is only 2-3 gravity points then I would blame it on the extract you are using. If it really bothers you, switch brands or go AG.

 

[simps984]

Another idea - you exercise strict temperature control, well make sure all those things are correctly calibrated. Perhaps if your thermometers are off a tad, you might be having a higher/lower mash temperature, or a higher/lower ferment temperature. The mash temp, for instance, would affect fermentability and thus, the final gravity.

 

[docmoran]

Appreciate all the responses -- yes, it is AG. Yes, I mean missing by .02!! I have not calibrated and will do so now. I have always wanted to push out several of the same beers to check system/yeast/technique and then dial in from there but always get excited about having multiple beers in line up. Will probably suck it up and stay same for a few now. thanks, doc

 

[irunxcjm]

While you're at it, I would check your thermometers as well. You might be mashing too cool or something if they are off. You should also check out the AG board and there are many threads about poor effeciency.

 

[IrregularPulse]

I don't know much about it since I've not used it, but are 2 vials of liquid yeast enough? I always thought a starter was required for vials? Possibly under pitching? Also how are you storing these vials once you receive them?

 

[Lou]

Yes, I mean missing by .02!!

so you're expecting to hit something around 1.012 and you're getting 1.032??

this is a big difference.

 

[menschmaschine]

If you can rule out all other possibilities, what's your water profile like?

 

[JesseRC]

Yeah you need to give us some real numbers or atleast an example, being off by .02 is a big deal, being off by .002, not so much.

 

[ericm]

are you consistently off high or low? or does it vary?

 

[JesseRC]

Ok, so you looked - now have a try. Although a noob I know enough about every conceivable variable involved in fermentation yet just dont get why I miss my FGs so consistently. I am always off by .02 - .03 in FGs and thats with Oxygenation/two liquid yeast vials/strict temp control etc!! I am ok with this as my beer is GOOD in my humble opinion -- just dont want to miss the full deal. Any comments on this PERPLEXING problem??? thanks, doc

Also, it's not just about every conceivable fermentation variable. You said this was AG, so then you have to think about your mash temps. If you mashed high, you would hit your OG but you may end up with a less fermentable wort. .02 seems like a lot. Can you give us an example and tell us about your recipe and mash technique. And if the recipe's are high gravity one, that may come into play as well.

 

[Boerderij_Kabouter]

I think you must be suffering from bad efficiency. Either in the mash, the sparge or both.

We need actual details to help.

 

[woollybugger2]

sorry... hit reply instead of new thread....