Big IIPA and the refractometer

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Don_T

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I have an IIPA in secondary fermentation. I recently got a refractometer to monitor the fermentation progress without having to take large samples of the precious goodness. My OG was 1.129. My last sample read 10 Brix which converted to 1.038. I've been reading as much as I can on alcohol content skewing the refractometer readings so the 1.038 is not accurate. I use Brew Pal and it has alcohol compensation which brings the reading to 0.977. I used the spread sheet from more beer and it came up with a very similar reading. This can't be correct given a predicted attenuation of around 75%.

Any thoughts on what is going on?
 

xerotime

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Have you calibrated your refractometer with distilled water? I only really use mine to get a quick pre-boil gravity and then use my hydrometer for fermenting/finished beer
 
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Refractometer was calibrated. Was planning on taking a hydrometer reading today. Was wondering if this is too big of a beer for the calculations to work.
 

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You cannot use a refractometer on a fermented beer. The alcohol throws it off. You need to go old school and use the hyrdometer. We had this same issue a little while back and found out that this was the issue.

We tested the theory, took a beer that just finished at 1.010 on the hydro and the refract gave 2 differenet numbers before primary and after secondary.

Calculations will always work, its math, it never fails.........

Give us some more info such as ingredients and such.......
 
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That's what I figured, that the refractometer isn't good to use on a beer that is fermenting. From what I read it sounded like the alcohol compensation calculations were supposed to work. Doesn't seem to work in this case.

Am I wrong to think I can use the refractometer to monitor the fermentation to see when the yeast stall out then take a hydro reading once the refractometer readings don't change in a few days?
 

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If you use Beersmith there is a calculation page for using a refract on beer while it is fermenting and after fermentation. I have used this many times and cross checked with a hydro and it is accurate. Post your readings and I can enter them into my beersmith page and give you the results.
 

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I have used a refractometer to measure fermented beer against a hydro on several occasions and it has always been spot on for me. Why not take a few hydro readings and compare against calibrated refractometer readings and see how it compares over a few beers. I've seen a few people complain around here about their refractometers, so I shold give mine another comparison.
 

TheMan

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I have compared mine to a hydro within the last two months or so, it's been within a point or two every time. And at a +/- 2 I can deal with not knowing the exact measurement. Beersmith takes care of the calculations for me.
 
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OG was 1.129, last refrac reading was 10 brix, maybe 9.8 brix.

Thanks for all the help, if you would beersmith this and let me know I will take a hydro reading this evening and we'll see what it says.

Question, when reading the refractometer there is a meniscus at the line, is the reading at the top of the meniscus just like reading a hydrometer?
 

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Question, when reading the refractometer there is a meniscus at the line, is the reading at the top of the meniscus just like reading a hydrometer?
Um... are you sure? The fluid is "squashed" between the prism and cover plate, there is no meniscus. Or are you meaning it goes from blue to white but the line is fuzzy?
 
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Yes that is what I am talking about. white, transition (fuzzy) area, blue. Where is the reading taken?
 

maida7

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OG was 1.129, last refrac reading was 10 brix, maybe 9.8 brix.

Thanks for all the help, if you would beersmith this and let me know I will take a hydro reading this evening and we'll see what it says.

Question, when reading the refractometer there is a meniscus at the line, is the reading at the top of the meniscus just like reading a hydrometer?
Sorry, beersmith uses the same formulas as all the other calculators. Like I said before. One or more of your readings is wrong. You need to use a hydrometer.
 
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Don_T

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Ok, took a hydro and refrac reading.
Hydrometer, 1.018 @ 60F
Refractometer, 10 brix, yes calibrated prior with distilled water.
OG was 1.128 @ 64F, 1.129 corrected.

I took almost 30 hours of chemistry in college so I tend to measure correctly, however there is always a chance of making an error. Depending on the amount of elixir I've imbibed during the brew session, and there was quite a bit during this one.

Here is the grain / extract bill that I brewed. If anyone is willing to plug it into Beersmith I would appreciate it. I only have Mac and am anxiously waiting for the Mac version of Beersmith. I use Brew Pal on my iPhone.

11lbs. LME
1.25 lbs. Dextrose
14 oz. alcohol booster sugar pack
3 lbs. Crystal 10L
1 lbs. Cara Pils
90 min. boil of 5.5 G
Grains were bag mashed at 155 F for 50 min. in 3 G, temperature was held quite constant.
sparge with 2 G of 155 F by suspending grain bag over boil kettle in a strainer and slowly pouring water over the top.
Water was a mixture of boiled and rested tap water and RO water.

2 oz. Nugget 13% for 90 min.
4 oz. Cascade 5.4% 8 min.
4 oz. Cascade 5.4% 5 min.
4 oz. Cascade 5.4% at flame out
there will be 4 oz. Cascade 5.4% dry hop for 1 week

Ok, let the analysis begin. Thanks for the help.
 
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The LME could have been up to 11.75 lbs. the scales at the HB store are less than accurate I'm sure. I pitched 2 packs of Safale US-05. I don't remember the brand of the alcohol booster pack, a friend brought it over so for the hell of it we threw it in.
 

BrewNinja1

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What was the actual OG brix? Or are you just using what the OG "should" have been?

I too only use a refractometer anymore. I found that its always very close after using corrections. I see people say they are off, but have to wonder if they have a bad one or arent using it right.
 
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I didn't have the refractometer when I started the fermentation.
 
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The OG was a hydrometer reading
 

Homercidal

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It certainly looks like your refractometer is reading wrong. I wonder what it would read against calibrated samples...

Check your hydrometer at 1.000 and then add sugar to water in increments, noting the difference in readings between the hydro and refractometer. I suspect you'll see a curve develop as the gravity goes up.
 
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Thanks for all the input. Seeing as how I didn't have the refractometer at the beginning of this brew and the possibility that my OG reading may have been wrong I'll just chock it up to hmmm. Another batch right around the corner so I'll be able to take before, during and after readings and see how it works. I need to run a few batches to figure my wort correction number anyway, may not be the assumed 1.04 with the big beers I'm brewing.

I'll mix up a batch of calibration liquid at a few concentrations as well and check the instrument for irregularities. Simple enough.
 
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I mixed up some sucrose solutions last night. My refractometer is WAY off.
9.8 for 10 brix (not too bad)
15.4 for 20 brix (bad)
23.2 for 30 brix (real bad)

Made the solutions with a digital scale as accurately as possible. Calibrated with distilled water before each measurement.

This sucks. Anyone have a reliable source for refractometers that aren't expensive, or is it like anything else? You get what you pay for.
 

Homercidal

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I don't know. I bought the cheapest I could find on Ebay and I think it's been ok so far. I tested it against my hydro for brewday and kegging day for 3-4 brews after I got it and it's been dead on each time.

With enough samples, you could theoretically map a correction curve for it...
 

logdrum

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I don't know. I bought the cheapest I could find on Ebay and I think it's been ok so far. I tested it against my hydro for brewday and kegging day for 3-4 brews after I got it and it's been dead on each time.

With enough samples, you could theoretically map a correction curve for it...
I too bought the ebay model & have had nothing but stellar results. Checked the first couple of brews vs the hydrometer & w/ the more beer spreadsheet they were within .002 points. Close enough for me.

-d
 

mattd2

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I mixed up some sucrose solutions last night. My refractometer is WAY off.
9.8 for 10 brix (not too bad)
15.4 for 20 brix (bad)
23.2 for 30 brix (real bad)

Made the solutions with a digital scale as accurately as possible. Calibrated with distilled water before each measurement.

This sucks. Anyone have a reliable source for refractometers that aren't expensive, or is it like anything else? You get what you pay for.
HAve you checked your distilled water is actually 1.000? just a thought ;)
 
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That's a thought. I was going to make a few more larger batches of sucrose solutions tonight to check them against the hydrometer. This was one of the ones off ebay, I think they will trade me out with a new one. We'll see.
 
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Ok, new data. Did some more measurement tonight. Measured my distilled water at 1.002. Made some sugar solutions, 1.109 (hydrometer), 26Bx (1.101). 1.073 (hydrometer), 18Bx (1.070). 1.040 (hydrometer), 9.6 Bx 1.037. So it seems to be spot on accurate. I used the long formula for my Bx conversions, and my samples were near ideal temps (59-63F). So, how can my wort measure 1.018 with the hydrometer, and 10 Bx which comes to .986 with the various alcohol compensation calculators?
 

BOBTHEukBREWER

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10 brix is not 0.986 it is nearer to 1.040 - you quote 1.040 hydrometer equated to 9.6 brix = 1.037 Wort made up of maltose and alcohol that measures 10 brix is SG 1.029
 
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The .986 is with an alcohol compensation equation. The solutions I measured last night were pure sucrose and distilled water.

Which calculator are you using for the 10 brix = 1.029 with alcohol? I've used pro mash and brew pal and the more beer spread sheet, they all come up with very similar numbers, all <1. Taking into account the OG of 1.129.
 
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