My New Refractometer

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Senior Member
May 29, 2009
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Ok, so yesterday my new refractometer arrived. Naturally I went to the sink and tested a drop of water. Zero brix for the tap water, wonderful. Then I tested some wine from a friends homemade, then wine from 2 of my home mades and a drop from a commercial wine. All tested at either 4, 5, or 6 Brix. I thought that all of the finished wines would be zero or close to +/- zero. So is it just me or is there someone out there who can explain that to me.

Richard, I personally dont have a clue, I am just glad that when you tested the tap water you didn't end up with a "5". Now, THAT would have been interesting!

Good question though, I am waiting to see what some of the others say.

Take Care
I remember reading somewhere that you can only test unfermented juice with a refractometer because the presence of alcahol will cause false readings.

I don't have one myself and really don't know for sure, but you could check into it.
The alcohol throws off the reading. You have to use a complex set of calculations (including the starting gravity) to determine the current gravity from a hydrometer reading. This was all done in a spreadsheet I downloaded long ago from MoreBeer.

I just found the video showing you how to use the spreadsheet (with a link to the spreadsheet as well. You can find it here:
A refractometer's measuring is thrown off if there is alcohol
in the juice you are testing.

So make a sugar solution, or non fermenting must, or lemonade (without co2), or fruit juice or whatever as long as there is no alcohol in it.

I use my refractometer all the time.

Did you know that if you have a digital camera with a macro function you can even take pictures through the lens of the refractometer which make a great addition to your winemaking log-book. You can see an example here:

So as you now know, I purchased a new refractometer without doing the research. No one to blame but me and Luc. Yep, that’s right, Luc. Not long ago I saw where Luc said something like, I always use my refractometer. So I got one and then learned that the alc distorts the reading. RunningWolf & Thetooth, told me about the distortion and referred me to sites with a formula to correct the distortion. Thank you to both, I tried it today and it does work, I think. You really have to start with a new must which I do not have at this time. The original brix must be known to get an accurate reading. Also, I normally use juice buckets that sometimes have already started to ferment when I receive them. Using my hydrometer readings I was able to back into the correct brix of an Amarone racked today and started in October, The meter said 7 and the formula corrected it to -3.3 or SG .987. My hydrometer substantiated it. Since I am really lazy, and don’t like the hydrometer, I’ll continue to use the refractometer and verifying with the hydrometer until I get more confidence in the it. But, Luc I would still like to learn how you use it.
Luc picks a lot of fruit and this area is where they shine. If you make beer these come in very handy also. Is your auto temp control? ATC (Calbration)
try a couple drops of distilled water and see if it zeros out.
So you blame me for the lazyness of yourself or the unwillingness to put some effort in yourself........

I measure my must before I start making my wine.
And that is the only time I do a measurement in the whole winemaking process.

When you buy a bucket of juice and it is already fermenting there is an easy way to obtain the original SG.
It is called the boiling off method.
You take 250 ml must that you want to measure. Take a hydrometer measurement. Boil it down to 120 ml and then fill up with distilled water. Do another hydrometer measurement.
Now start fermcalc:
and go to the alcohol tab and look at the boiling off method.
You will now now the SG of the must and the alcohol that is already in it.
From the amount of alcohol you can derive the amount of sugar that has already been used, and adding that to the sugar that is still in the must you know what the initial SG is.

For keeping records of SG proceedings you can use the already mentioned spreadsheets. I use this one:

Nothing you could not have found yourself.

So next time before accusing people and blaming others then yourself think first. You could also have asked politely.

Luc, as I typed your name, there was a smile on my face, as there is now. I hope that as you read my post, a smile grew on your face and another when you responded. Though your answer was a little sharper than expected. I tried to inject just a little humor at my expence. Certainly not being critical of you. I’m smiling now and I hope you too, at least have a little grin. :)

Thanks for the info, I do keep a record of SG and check it until it reaches zero of less.
This is the reason I wanted Luc to be a mod on this site as he is chock full of info like this.
Maybe I overreacted a bit and maybe the humor went past me.

The grin is certainly here now :D

OK, here I come again. I think I mentioned in a previous post that I am lazy. I know Luc posted, “How to determine starting gravity”, which I'm sure is accurate. But being true to my laziness, does anyone agree or disagree that the following will work?

Using the Valley Vintner spread sheet, and obtaining the correct current brix with my hydrometer, I placed the correct current brix in the observed refractometer reading (AB) block on the spreadsheet. Then try inserting numbers into the starting brix (OB) block until the observed refractometer reading and the adjusted brix are the same. At this time the starting brix (OB) should be correct.
If your question is, "does the vintners calcularor work?", you should be able to test it with some 'knowns'. If it tests out ok with something standard, then it should work for 'unknowns'. Or check it against another method.

Sorry, I dont have any programs anymore that will open that file and even though I have the disk it wont let me download it anymore (Microsoft Office)
Open Office can handle the file flawlessly.

Like I told you in another thread Wade: Linux rules :try

I downloaded that program now that I think of it. I wonder why it didnt open when I tried to open that file, Ill try again.

Edit: There we go, I never checked the "choose program" and remember option. Thanks again.