first time this has happened.

[Soulshine2]

2 weeks ago I brewed,by style and its numerical characteristics its an American premium lager if it makes any difference . my norm for all of my brews up til now is 10-14 days in the fermenter and its done ,like swiss clockwork right? basement has been perfect upper 50's -mid 60's and optimal for the yeast (34/70) so thursday is day 13 ,i go down to do a gravity check and im still a solid 10 points from what I think is done (OG was 1.058...target FG is 1.010-12 ) Im at 1.024 still , wort/beer is 53 degrees. so I put a heat mat under it to give it a boost to get it going again. yesterday (24 hrs forward from the heat mat ) its 63 degrees according to the stick-on fermenter thermometer and been back to fermenting and i recheck , its now at 1.026 . im using a digital refractometer with 2 drops on the lens ,i thought temperature didnt matter with these. How did the gravity go up ?

 

[balrog]

Were that to happen to me, I would use a hydrometer to check. I've found scattered results using refractometer for FG, regardless of the equations/calculators used to "correct for the presence of alcohol".

 

[Soulshine2]

I'll try that , i know i used to use the hydro until i got this refracto,less sample lost ,right? ...if it is in the ballpark ill cut off the heat and let it crash , hoping to bottle in a few days while i still have time.

 

[balrog]

 

[Soulshine2]

this was a 5 gallon batch using a base of 10# weyerman barke pilsner. kind of a kitchen sink inventory clean out brew ,little vienna , little munich ...its a darker pils ,not quite amber. 2oz hallertauer , good flavor so far

 

[brewbama]

How much yeast did you pitch? Did you use yeast nutrient?

I’ve found a healthy pitch and yeast nutrient helps start fast, finish fast, and finish at expected AA. I used to get sluggish, slow ferments before, now I am fermenting lagers in 6-7 days and ales in 4-5. The airlock sounds likes a Gatling gun.

However, I also ferment 34/70 at 60*F.

 

[Hwk-I-St8]

Refractometers don't give accurate readings once there's alcohol in solution. There are calculaters that use the OG and current reading to figure ot current gravity, but why? Use a hydrometer, do it right and enjoy the sample after.

 

[kh54s10]

Did you make the correction for the presence of alcohol when using the refractometer.
If so did you use the same program/formula to do the correction.
It is not possible for the gravity to go up so there is error in the reading of the refractometer or in the correction calculations.

 

[Jag75]

This is why a tilt is in my future . When brewing lagers it will be really nice to know when to start upping the temp slowly.

 

[Soulshine2]

How much yeast did you pitch? Did you use yeast nutrient?

I’ve found a healthy pitch and yeast nutrient helps start fast, finish fast, and finish at expected AA. I used to get sluggish, slow ferments before, now I am fermenting lagers in 6-7 days and ales in 4-5. The airlock sounds likes a Gatling gun.

However, I also ferment 34/70 at 60*F.

same as I always pitch and never an issue. one 11 g packet per 5-6 gallon .

 

[Soulshine2]

Refractometers don't give accurate readings once there's alcohol in solution. There are calculaters that use the OG and current reading to figure ot current gravity, but why? Use a hydrometer, do it right and enjoy the sample after.

in the past thats what I have done. I was just using the refracto to not pull so much sample . i'll check it again today and I guess i'll go old school and use both the refracto and the hydrometer. i know both before and after i refract i do a calibration with tap water ...which btw is always .01 bx
what calculators are there for the alcohol presence ? I use an app on my phone for the gravity /alcohol calcs.

 

[Soulshine2]

Did you make the correction for the presence of alcohol when using the refractometer.
If so did you use the same program/formula to do the correction.
It is not possible for the gravity to go up so there is error in the reading of the refractometer or in the correction calculations.

exactly, thats what has me puzzled.

 

[Soulshine2]

ok , so after this post , yesterday morning I went down and pulled a sample for the hydrometer and rechecked it against the refractometer. refract said the same 1.024 while my handy dandy hydro read spot on my target FG , 1.012 . Its done and the sample looks ,smells and tastes wonderful. I plan on bottling today. Its looking like its a 6% abv Lager.
So, looking back , even with all the electronic gizmos and gadjets available , the old manual stuff is still more accurate ,tried and true . The short cut or step you attempt to save isnt always in the best interest of finding out what you want. Looks like the hydro wins over the refractometer in this case. Maybe it'd all match if I knew how to do the alcohol correction.

 

[Soulshine2]

View attachment 663588

please explain, some of the header is cut off and I dont know what the numbers represent. do you have the link to the source of this chart?

 

[S-Met]

There are loads threads here regarding off gravity readings linked to misunderstanding of refractometers.

Readers digest version: refractometer measures brix or sugar in liquid. I think some have other non-brix scales,not sure though. Presence of alcohol offsets the refractive index as compared to water/juice. As alcohol forms, a correction factor needs to be applied for an accurate reading.

At least until you trust and learn your device, most use to monitor progress and confirm stability with a drop rather than 200ml sample each time. Once you are stable, measuring fg with your hydrometer.

 

[balrog]

please explain, some of the header is cut off and I dont know what the numbers represent. do you have the link to the source of this chart?

That's my data, my spreadsheet, my batches, measuring OG/FG, Rinitial, Rfinal, using different formulas to determine if any formula worked for me and my batches. I showed it merely as my example of my samples and the errors I am getting, sometimes I am certain based on my measurement errors.

 

[Soulshine2]

There are loads threads here regarding off gravity readings linked to misunderstanding of refractometers.

Readers digest version: refractometer measures brix or sugar in liquid. I think some have other non-brix scales,not sure though. Presence of alcohol offsets the refractive index as compared to water/juice. As alcohol forms, a correction factor needs to be applied for an accurate reading.

At least until you trust and learn your device, most use to monitor progress and confirm stability with a drop rather than 200ml sample each time. Once you are stable, measuring fg with your hydrometer.

i understand, thank you

 

[Soulshine2]

60 bottles yesterday . in 10-14 days I should be cracking one.

 

[jgmillr1]

The short cut or step you attempt to save isnt always in the best interest of finding out what you want. Looks like the hydro wins over the refractometer in this case.

The refractometer is a good way to monitor the progress of your fermentation for the very reason you had said earlier: no need for temperature correction and only a couple drops of liquid. And you were aware of the alcohol convoluting the exact end result. This is what I use it for with my wine.

Now that you know the refractometer will measure about 1.024 at completion, then you have an approximate target value to track it against. Collecting both the hydro and refractometer readings on upcoming batches will give you a better feel for using it solo later.