Hydro says done, refracto says not done

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Octavius

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Cornfused.

This is the recipe for Wheat beer from the July 2011 of BYO.
It should have a OG of 1.049 and FG of 1.012 (with Wyeast 3944)

Instead I used Flanders Golden (Wyeast says gives an attenuation of approx 70%, ie in this recipe down to 1.015).

It has been fermenting for 9 days at RT (approx 74F). Vigorous at first (using blow-off tube) but now seems over (no bubbles in fermentation lock).

To my uneducated palate it tastes sweet. Confirmed by a refractometer(calibrated with sugar solution) reading 0f 6.2 Brix (approx 1.025 SG).

However, the fermentation appears over and my trusty hydrometer (that I have had forever) reads 1.006 at 74F.

I've never used this yeast before - has anybody got any ideas?

Cheers!
 
I'd trust a hydrometer over some kind of wonky "calibrated" refractometer reading for a fermented beer any day. If you check your hydrometer in distilled water and it reads 1.000 then in your beer and it reads 1.006...it's 1.006. After fermenting for that period of time at that temperature, it's done unless you somehow underpitched.
 
Unless you have a correction for the refractometer, it is way off. They are made for water solutions only - not ones containing alcohol.

As long as your hydrometer is calibrated, go with that.

And, no matter the FG, its not done until the SG is stable.
 
Cornfused.

This is the recipe for Wheat beer from the July 2011 of BYO.
It should have a OG of 1.049 and FG of 1.012 (with Wyeast 3944)

Instead I used Flanders Golden (Wyeast says gives an attenuation of approx 70%, ie in this recipe down to 1.015).

It has been fermenting for 9 days at RT (approx 74F). Vigorous at first (using blow-off tube) but now seems over (no bubbles in fermentation lock).

To my uneducated palate it tastes sweet. Confirmed by a refractometer(calibrated with sugar solution) reading 0f 6.2 Brix (approx 1.025 SG).

However, the fermentation appears over and my trusty hydrometer (that I have had forever) reads 1.006 at 74F.

I've never used this yeast before - has anybody got any ideas?

Cheers!

Did you correct the refractometer reading for alcohol?

If your original refractometer reading was 1.049 and your fermented out reading is 1.025 uncorrected for alcohol, then the corrected for alcohol refractometer reading is 1.009 and close to your hydrometer reading. You didn't specify how close you were to the expected OG and this is critical to adjusting for the alcohol. Could this be the explanation? I'm not a huge fan of refractometers for anything but estimating OG during the boil.
 
For an OG of 1.049, a reading of 6.2 Brix indicates a gravity of 1.010 according to Promash. However, I've never found the refractometer conversions to be very accurate once fermentation has started, so I'd believe the hydrometer.

-a.
 
osagedr,
I think you are correct!
I've just taken readings from the other identical brew (made 10 gal, split it into two 5 gal) that used Wyeast Forbidden Fruit 3463. That gave 6.5 Brix but 1.012 SG at 75F.
I tasted that (and re-tasted the previous brew) and decided that what I thought was sweetness is in actual fact the "softness" of uncarbonated wheat beer. (I've been brewing IPAs for the last couple of years and they don't taste "soft").
Well, that solves that problem - except for the poxy hydrometer. I checked it against tap water and it reads zero. Maybe it got confused with the solid particles of the wheat beer sample. Kind of irritating as I was hoping to use to determine when fermentation is over - a lot more convenient that taking a hydrometer sample.
Thanks for the reply.
Cheers!
 
Younggrad, Ricand and ajf,
Thanks for the replies!
Wow! I didn't know you had to correct the reading for alcohol, doh!
Back to the books for me.
Many thanks - clears up the mystery!
Cheers!
 
You can still use the refractometer to judge when fermentation is finished. when the brix reading stops dropping, it's done. It just won't give you a very accurate FG.

-a.
 
You can still use the refractometer to judge when fermentation is finished. when the brix reading stops dropping, it's done. It just won't give you a very accurate FG.

-a.

Fair dinkum. Thanks!
 
Refractometers are useless, particularly for checking FG. The will check low for OG, because they are only measuring one type of sugar while a beer has many, and they always measure high for FG, because the alcohol causes the light to refract differently. Use a hydrometer for everything, and you can't go wrong.
 
Refractometers are useless, particularly for checking FG. The will check low for OG, because they are only measuring one type of sugar while a beer has many, and they always measure high for FG, because the alcohol causes the light to refract differently. Use a hydrometer for everything, and you can't go wrong.

I have a refractometer and two hydrometers. I get w/i 0.001-0.002 between the refractometer and hydrometers for pre-fermentation specific gravities. And I can take many quick measurements over the course of a brewday with the refractometer. No need to take time to cool a sample and no need to get several ounces for the measurement.

So, I think the refractometer is great for those who adjust gravity on the fly. Of course, once you have brewed beers of every gravity and know how your system functions over every gravity, there's probably no need to measure.
 
I do use mine to check sparge gravity to make sure im over 1.010, but that's it. The last beer I made checked out 1.070 on the hydrometer, and 1.060 on the refractometer
 
I do use mine to check sparge gravity to make sure im over 1.010, but that's it. The last beer I made checked out 1.070 on the hydrometer, and 1.060 on the refractometer

That could be because of a bad hydrometer, or a bad refractometer, or because the refractometer is not properly calibrated.
For details on how to calibrate the refractometer, download a trial version of Promash. From the main screen select Options->System Settings->Instrument Calibration->help.
I followed the suggested procedure, and my refractometer gives me very accurate readings for unfermented wort, but I use a finishing hydrometer to get the FG.

-a.
 
ajf said:
That could be because of a bad hydrometer, or a bad refractometer, or because the refractometer is not properly calibrated.
For details on how to calibrate the refractometer, download a trial version of Promash. From the main screen select Options->System Settings->Instrument Calibration->help.
I followed the suggested procedure, and my refractometer gives me very accurate readings for unfermented wort, but I use a finishing hydrometer to get the FG.

-a.

None of the above. Its fairly well known that they don't work worth a damn without complex conversion charts or conversion software. If a hydrometer reads 1.00 in water, it is calibrated. If a refractometer reads 1.00 in water, IT is calibrated. When they both read differently after that, you know that one of them isn't working properly. And its the hydrometer.
 
Refractometers are useless, particularly for checking FG. The will check low for OG, because they are only measuring one type of sugar while a beer has many, and they always measure high for FG, because the alcohol causes the light to refract differently. Use a hydrometer for everything, and you can't go wrong.


Mine is always dead nuts on before and after fermentation. I couldn't imagine my refractions are reading low... After 16 years of brewing, I don't think I can get much higher than mid to low 90's with my extraction efficiency.

On the otherhand. I do own a hydrometer with a .990 to 1.020 scale that is way off.
 
Chesterbelloc said:
Mine is always dead nuts on before and after fermentation. I couldn't imagine my refractions are reading low... After 16 years of brewing, I don't think I can get much higher than mid to low 90's

Unless you are using conversions to get you true FG based on your refractometer reading, this is simply not possible IMHO, regardless of how long you've been brewing. The presence of alcohol disturbs the light refraction. The more alcohol, the more wrong it is. This isn't even a topic for debate, its simple fact.
 
You can still use the refractometer to judge when fermentation is finished. when the brix reading stops dropping, it's done. It just won't give you a very accurate FG.

-a.

I recently got a refractometer. I did find the alcohol conversion previously. I also read the threads concerning hydro vs refract. and decided that it is still VERY useful. I will use it to confirm the gravity has stopped dropping (2 drop samples instead of a tubeful) then I'll take a final gravity reading with the hydro for all the last info and calculations like ABV.
 
kh54s10 said:
I recently got a refractometer. I did find the alcohol conversion previously. I also read the threads concerning hydro vs refract. and decided that it is still VERY useful. I will use it to confirm the gravity has stopped dropping (2 drop samples instead of a tubeful) then I'll take a final gravity reading with the hydro for all the last info and calculations like ABV.

I do acknowledge that it is good for this kind of thing. I only check fg twice during fermentation, once when I know its done, and again a few days later to be sure.
 
Unless you are using conversions to get you true FG based on your refractometer reading, this is simply not possible IMHO, regardless of how long you've been brewing. The presence of alcohol disturbs the light refraction. The more alcohol, the more wrong it is. This isn't even a topic for debate, its simple fact.

No one is disagreeing with this. Everyone who knows how to use a refractometer after fermentation has started knows to use a formula to compensate for the presence of EtOH. It is assumed that the measurement is adjusted and that is how it is still accurate after fermentation.

FWIW, I found a different conversion formula somewhere on this website for post-fermentation adjustment that I have found fairly accurate compared with my hydrometers.
 
None of the above. Its fairly well known that they don't work worth a damn without complex conversion charts or conversion software. If a hydrometer reads 1.00 in water, it is calibrated. If a refractometer reads 1.00 in water, IT is calibrated. When they both read differently after that, you know that one of them isn't working properly. And its the hydrometer.
My refractometer reads 0.00 in water not 1.00. (it reads in Brix). If you calibrated it to read 1.00, then it's way out of calibration (or it doesn't read in Brix). But that's just the first part of calibration. The second part is to adjust for the difference between wort and a simple sucrose solution. This is a simple adjustment of the conversion algorithm rather than an adjustment to the refractometer.
If your refractometer (after conversion) report a gravity of 1.060 when the true gravity is 1.070, then there is clearly a problem. If it wasn't poor calibration, bad hydrometer, or bad refractometer; the only remaining cause of the error is the user.

-a.
 
Is it really this hard for people to use a refractometer? I rarely use a hydrometer, when I do it is at the end of ferment when I want to sample a taste. I kill two birds with one stone that way. I test and taste. I don't see how a hydrometer is any more reliable. I'm not really sure some people know how to read a hydrometer. I think a lot of times people fudge the reading to get what they expect.
 
iaefebs said:
I'm not really sure some people know how to read a hydrometer. I think a lot of times people fudge the reading to get what they expect.

Since we're all here, why don't you tell us how you do it? Assuming of course that you actually meant refractometer and not hydrometer. A hydrometer is pretty easy to read.
 
Since we're all here, why don't you tell us how you do it? Assuming of course that you actually meant refractometer and not hydrometer. A hydrometer is pretty easy to read.

No I meant that some people have a hard time reading a Hydrometer. Understanding the meniscus line seems to be causing trouble. People read above and below the line. To read a refractometer I put a couple drops on the prism and read the result.... simple. If it's pre or post boil I use the result... if it's ferment I convert the reading with Beersmith 2 or an online calculator.
 
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