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Hoptimus Maximus

Refractometer RSG 32ATC

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Well my new Refractometer (RSG 32ATC) arrived this morning and so I have a new toy to play with and get used to.

http://www.ebay.com.au/itm/270748552919?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

Cost $29.80 (incl postage). The ATC in the model number indicates automatic temperature correction model.

Checked the calibration with RO water and the null line is spot on as they say null calibration is checked before leaving factory.

I thought I would do a test by putting a starter on the stir-plate which I need for a brew I have planned.

100gms DME and 1000ml water plus some nutrient has produced a wort which the refractometer says has OG of 1.0435 and Brix of 11.2. This was a little higher than I had expected but is confirmed with a hydrometer which gives a 1.043 reading.

First thing I notice is how much easier it is to read the scale on the refractometer compared to the hydrometer. I aim it into my halogen desk lamp and can easily get a clear half point reading which would be guesswork with the hydrometer.

Not sure if there is any value in this little exercise but I will read it at regular intervals and see how the readings line up between the hydrometer and the refractometer using Morebeer's Excel Calculator if necessary.

How great it will be if it can be used to calculate accurate readings throughout the fermentation process as you only take a couple of drops of the wort to do your reading. I will post my experience with it.

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Yes, keep us informed please. I have been debating whether or not to get one, I will eventually.

 

How does it do the automatic temp correction?

Are they hard to clean?

Do you still do a "run off" first before taking a sample?

How did you extraced the wort from the FV to use for a sample?

How often would you expect to have to change a pipette?

Ebay site claims that it reads unfermented wort. So does this actually mean it is no good to take a FG considering the wort is then fermented?

 

Sorry about all the questions.... just some things I'd like to see answers. However, I understand you only just got it so, "give the man a break" [bandit]

 

A lot of the calculators around; if you enter brix 11.2 they are coming up with a SG 1.045 so i am not sure what gives there.

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I have bought the same one just waiting on it to arrive.

 

Your OG you just take your brix and refer it across to the chart in the refrac for your OG pre fermentation but for your final you need to do a calculation with your FG or use a hydrometer in association with it, heres a good little calculator.

 

Calculator Brix to FG

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Also remember we are only wasting a few drops of beer compared to a couple of glass's of it.

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Also remember we are only wasting a few drops of beer compared to a couple of glass's of it.

 

I don't waste mine... it goes down the hatch [innocent] and considering I usually only take 3 readings, I'd probably only have 1 glass [rightful]

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Yeah i got to agree Bill, i dont mind a sip before and after and 3 reading is my limit pretty much, maybe i dont need a whole testing glass to get a taste [lol] then again maybe i do....

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Yes, keep us informed please. I have been debating whether or not to get one, I will eventually.

 

How does it do the automatic temp correction?

Do not know it just does it somehow??

Are they hard to clean?

Very easy - just wipe with cotton cloth.

Do you still do a "run off" first before taking a sample?

No just take it from the top.

How did you extraced the wort from the FV to use for a sample?

I used one of the disposable plastic pipettes that come with it to take a sample from the Erlenmeyer flask. You only want a couple of drops. I believe you could keep reusing over again just squirt out with RO water. I do have a long 10ml glass pipette which I could sterilise and use as required if necessary.

For the FV I guess I will just get a couple of drops out of the tap onto the refractor glass

How often would you expect to have to change a pipette?

Never probably if I use the tap - I will test and see if reusing a cleaned disposable gives different reading to a new one.

Ebay site claims that it reads unfermented wort. So does this actually mean it is no good to take a FG considering the wort is then fermented?

Well Bill the Jury is out for me on that until I finish my little play around. I would expect to have to use the calculator if it is to be of value but no previous convictions on that one.

 

Sorry about all the questions.... just some things I'd like to see answers. However, I understand you only just got it so, "give the man a break" [bandit]

 

A lot of the calculators around; if you enter brix 11.2 they are coming up with a SG 1.045 so i am not sure what gives there.

This unit has both Brix and SG showing on 2 different scales when you do the peep test. No need for calculator.

 

 

 

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First reading after 6 hours not so easy to read with confidence like OG reading. There appears to be no clear horizon to read accurately. It is more like a graduated colour change from white to grey. Wonder if that is the yeast in solution?

I guessed what the refractometer was indicating and came up with Brix 10.4 SG 1041. Hydrometers show around 1.041. No calculator was used to adjust that refractometer reading. But it was not clear and I suspect if different people read the refractometer they could have different opinions up to a couple of sg points apart.

I note the calculators show Brix 10.4 as SG 1.040 but the lines on the scales on the refractometer do not appear to concur with the calculators? 10.4 appears to line up with 1.041 but maybe my eyes are deceiving me. Otherwise all good.

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Do the Fractometer reading before pitching yeast as the Brix falls dramatically after pitching for about 3 days then levels out. The Brix reading to SG is a times 4 conversion so 10.4 (seems low as would being showing because you did the reading after pitching yeast)) that would equate to 1.0416 so lets say 1.042 to round it up (its actually according to the calculator 1.042557512402427), but when you measure FG the alcohol throws it out. Lets say our FG was 5 brix the original calculation would make it 1.020 but in actual fact its 1.006 or a bit shy of 4% abv. I am guessing your initial reading may have been as high as 13 or 14 Brix without the yeast.

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Do the Fractometer reading before pitching yeast as the Brix falls dramatically after pitching for about 3 days then levels out. The Brix reading to SG is a times 4 conversion so 10.4 (seems low as would being showing because you did the reading after pitching yeast)) that would equate to 1.0416 so lets say 1.042 to round it up (its actually according to the calculator 1.042557512402427)' date=' but when you measure FG the alcohol throws it out. Lets say our FG was 5 brix the original calculation would make it 1.020 but in actual fact its 1.006 or a bit shy of 4% abv. I am guessing your initial reading may have been as high as 13 or 14 Brix without the yeast.[/quote']

 

My initial reading was taken before pitching the yeast and the refractor horizon line was crystal clear(sharp) at an OG of 1.0435.

The refractor horizon line seems to have lost its sharpness which lends itself to a bit of guesswork. I will take another sampling in the morning. The positive is my defrosted Wyeast 1056 - American Ale yeast appear to have taken off ok even though no real obvious activity the SG is heading south.

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I just re-read your 1st post duh to me

i thought you did the 1st OG after pitching the yeast

but alls good, i am tired and shouldnt be posting on forums

[roll]

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Update after starter on plate for 19 hours.

Hydrometer reading is 1.026

With the refractometer the reading as previously discussed is still not sharp and I guessed it was saying 8.0 Brix.

Plugged that figure into my MoorBeer Calculator(free online) and it tells me SG is 1.024. I do think I am getting the hang of aiming the device at a light source and that is making the reading a little more defined. Still not sharp but easier to make a decision.

Error is 2 points and that is hardly a big deal. Perhaps if it transpires it always (with the software adjustment)calculates a reading +2 points that would be nice to know.

Nice to know those 1056s are not sleeping on the job.

 

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I have reached the conclusion after 5 readings over 29 hours that there will be a variation to hydrometer readings taken at the same time despite using the refractor calculator. Variations are in the range 2 - 3 points.

The error rate was worse as the alcohol content rises.

Latest Hydrometer reading 1.016 Refractometer calculates 1.013.

If for whatever unnecessary reason you want to take lots of SG readings throughout the brew and fermentation then this is a useful tool. I recommend confirm OG and FG with hydrometer.

I have taken the starter of the stirplate and will take a final reading tomorrow after the yeast flocculate just to satisfy myself that it is not suspended yeast that contributes to the variation rather than alcohol content alone.

I have no regrets about the purchase yet.

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John how long did it take to get your refractometer

i am starting a new brew on Saturday and would like to try it out on that. I ordered last weekend

 

I recommend confirm OG and FG with hydrometer

 

Yes true especially FG, but thats all dependent on your hydrometer being accurate [rightful] alot arnt and a re out a few points, but i have no idea what you are using which one you are using.

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John how long did it take to get your refractometer

i am starting a new brew on Saturday and would like to try it out on that. I ordered last weekend

 

Tony I ordered on 20/7/11 and it did not turn up. I put in a PayPal Dispute and the seller sent me another one by registered airmail. He posted 30/8/11 I received it on 13/9/11. Other one still has not turned up. I also ordered a little digital thermometer at same time and that never turned either. They also sent a replacement and the original turned up today. Maybe Customs sitting on them or HK Post?

 

I recommend confirm OG and FG with hydrometer

 

Yes true especially FG, but thats all dependent on your hydrometer being accurate [rightful] alot arnt and a re out a few points, but i have no idea what you are using which one you are using.

 

I am using this one

 

 

 

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I ordered my refractometer (same as yours same dealer) on the 9th and hes just marked it as posted tonight the 15th at 6:15pm so i will see how he goes, i have never used a digital hydrometer so i cant say anything about them, i have an accurate glass one. I have never had problems out of Hong Kong/China for that matter ever. Have even bought a resonator guitar out of there and its a ripper a GPS that works as good as the name brands and some other bits and pieces.

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I ordered my refractometer (same as yours same dealer) on the 9th and hes just marked it as posted tonight the 15th at 6:15pm so i will see how he goes' date=' i have never used a digital hydrometer so i cant say anything about them, i have an accurate glass one. I have never had problems out of Hong Kong/China for that matter ever. Have even bought a resonator guitar out of there and its a ripper a GPS that works as good as the name brands and some other bits and pieces.[/quote']

 

I like you have only good things to say about dealing with Chinese suppliers. I had a STC 1000 fail and they replaced it without argument, 2 very late items and they have both been resent. One of the missing items arrived after 2 months other still not sighted.

Were you meaning digital thermometer not digital hydrometer?

 

Took a reading of starter at 44 hours(yeast have flocced). Hydrometer says 1.011 and refractometer 1.009. The 1.009 was based on my reading of the hazy horizon. Someone else could have got 1.011 but that was the reading I decided before doing the hydrometer.

I am happy with this unit.

 

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Thanks for the info. TBH I think I'd rather just use the Hydrometer by the sounds of things. Considering I only take the bare essential readings and I really don't waste anything anyway, if having a refractometer for the sake of still having to take 2 readings instead of 3 with a Hydrometer, I think I'm happy the way it is [bandit]

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Thanks for the info. TBH I think I'd rather just use the Hydrometer by the sounds of things. Considering I only take the bare essential readings and I really don't waste anything anyway' date=' if having a refractometer for the sake of still having to take 2 readings instead of 3 with a Hydrometer, I think I'm happy the way it is [bandit']

 

I agree Bill not necessary and just another tool. It really comes into its own on brew day when you can take very quick and accurate readings of hot wort pre and post boil with just a couple of drops and no long wait for sample to cool.

Now I have it I will probably take more readings just so I can keep my finger on the pulse. I do like to know how a brew is progressing especially if it is a longer ferment. Only need to open tap and take 2 drops. Will still confirm OG and FG with Hydrometer.

 

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After reading up a bit on it they adjust the temperature if the temp is between 10C & 30C. I can see the value in them if boiling hot wort because the fact that it doesn't take long to cool a few drops to below 30C to take a reading. However, the first few readings taken from hot wort (then cooled) can be returned to the kettle/urn anyway. It just takes a little longer to reduce the temp.

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Hello,

 

I'm new to the forum, and new to brewing, but I just happened to see this older thread concerning the usefullness of a refractometer. Well, I just finished my first brew day, using a hydrometer, and it certainly worked, but I was horrified by the volume of sample it required.

 

For a profession, I'm a medical labratorian, and I have been using refractometers for 30 years, they are not new, not fancy & not difficult to use & it takes literally, 2 drops of sample.

 

A quick squirt with water & gentle wipe is all that's needed for cleaning, a refractometer should last years & years. We have ones in our lab, which are used many, many times every day, 365 days a year, and have been using the same 2 or 3 for 11 years, no problem with breakage, calibration is very stable.

 

After "playing' with the hydrometer, I can definitely say a refractometer can have many advantages, I know one will be in my future brewing tool bag.

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Hi Gayle

I understand where you are coming from but bare in mind that there is no need to fill the Hydrometer tube to take a reading. You only need to make the Hydrometer float which is about a bit over half a tube. I usually take 3 readings and drink the samples so no waste. I recommend at least tasting your samples every time. This way you will know for certain if your brew is infected or at least taste funky.

 

I personally only see the advantage with refractometers if you are brewing AG.

 

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Hi BillK

 

I was unaware half full would be sufficient, that's great to know.

 

I "inherited" (hand-me-downs) most of the equipment I am starting out with, so I didn't have any directions or instructions for ANY thing. As I said, I'm a lab person, so naturally to me, almost full would seem appropriate, my thinking being, why make it that size if it doesn't need to be that size.

 

Sampling/tasting during readings is a very good suggestion, it makes absolute sense !!

 

GayleV - Maine

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The tube is usually held as a storage container for the hydrometer as well. I'd guess and say that is why it is so long. Also it enables a little extra room in case of spills.

 

One thing you may like to consider with your equipment. No need to use the airlock. It will just cause confusion for you. Take a piece of gladwrap and put it over the top of the fermenter with the o-ring that is in your lid to secure it like a big jar of home made jam. This will eliminate a lot of up coming issues you may have.

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