Calibrating your Hydrometer

[Pumpkinman]

There's been a lot of talk about whether the wine has fermented to dry, most times it is a matter of a small percentage, could this be an error with the instrument? One way to tell is to calibrate it!
I read this on another wine forum, and Ironic enough, I found it in Wine Makers Mag as well.
To be absolutely certain your tools read correctly it is smart to check them from time to time, and easy way to check your hydrometer and refractometer is to make a 25 Brix solution.
Dissolve 25 g of sugar in 75 g of water (approx 1/3 cup), and you will have a 25 °Brix solution.
I had to make 2 batches to fill my hydrometer testing tube.
My Hydrometer and refractometer are spot on.

Here is the link to the article: http://winemakermag.com/127-calibrate-your-winemaking-tools

 

[djrockinsteve]

This is why I give my musts a teaspoon of super ferment to give an extra boost to finish fermenting then give it a few days under a lid with an airlock. Be patient.

Proper time to clear, degas and age before back sweetening just in case a few yeasts survive and sugar is still available. Better safe than sorry.

Thanks

 

[DoctorCAD]

How do you know if your water is 1.000 eith that method?

Easier to calibrate with distilled and temperature correct water...

 

[Pumpkinman]

Doctorcad,
This method has been used for years by home winemakers and professionals alike, you can use the method that you are comfortable with; I'm just trying to help fellow winemakers that are questioning gravity readings that may be a percentage or two off, they now have a method to check the "integrity" of their tools.

 

[theTheme]

I found another wine maker article and their method seems much simpler: Measure water at exactly 60 F and hydrometer should read 0s. Is one method more accurate than the other?

Here's the article link

 

[Pumpkinman]

theTheme,
I don't look for easy, I try to look for accurate. There are several ways to test your tools, you can test it anyway that you see fit.

 

[theTheme]

theTheme,
I don't look for easy, I try to look for accurate. There are several ways to test your tools, you can test it anyway that you see fit.

To be fair (and to answer my own question), the article you cite says you must do both in order to have maximum accuracy.

From the article:
"Checking the reading of your refractometer or hydrometer with pure water is a single-point calibration ... However, ... what if the scale printed on the paper sleeve inside the hydrometer was compressed or elongated compared to what it should be? ... the instrument could read correctly at zero, but not at higher values.
To be absolutely certain your tools read correctly across their entire relevant range, you need to do a two-point calibration. And, in order to do a two-point conversion, you need to make a solution of known sugar content."

As a practical matter, I'm not sure how you could compress or elongate a piece of paper (like the one with the scale on it). A print error would do it though. If you find an error between 0 and 15 brix, wouldn't it be better to throw the meter out? That would be like a ruler that measured correctly at 6 inches, but then actually spanned 8" between the 6" and 12" mark, tough to compensate.

 

[Pumpkinman]

theTheme,
I see your point. to be honest, I really use my hydrometer as a reference, what I mean is, for me, when I place my hydrometer in the wine and it reads 1.020, it really doesn't make much more of a difference to me if it were 1.018, I know that fermentation isn't complete, the same goes for .996 & .994, I know fermentation is complete, to take it one step further, let's say that your must starts at 1.090 and is finished at .996, the ABV will be 12.4 %, if it is .994 the ABV will be 12.7%, not really enough of a difference for me to get stressed about.
When I first started making wine, I'd check my wine twice a day, now I usually take an initial reading, then I won't take a reading for a few days.
Anyway, I'll do a 25 brix test of both Hydrometers at the beginning of the season and compensate for any discrepancies when I take my readings.
If you are going to get rid of hydrometers, please send them here so I can dispose of them properly.

 

[theTheme]

Well said. I suppose in the context of the home wine maker it is largely a theoretical exercise (and perhaps for the pros too since they get a 1.5% tolerance in both directions!).

I remember when I was learning to cook, I was obsessed with measuring everything exactly. Over time experience started to take the place of the measuring tools until after a few years I rarely measure anything (I don't bake).

If you are going to get rid of hydrometers, please send them here so I can dispose of them properly.

There used to be a great site on the internet in a similar vein (dimes not hydrometers). It is gone now, but the WayBack Machine still has it.

 

[Runningwolf]

As said above I use it for a reference. Except or starting brix, i look at it for a quick reference as to where my fermentation is. Tom what would you do with bad hydrometers? If I had one I had to + or - readings on I would toss it out.

 

[jamesngalveston]

dang...my hero has always been wonder woman, but I think running wolf is gaining ground....
If mine is off a lot..I toss it...I am waiting for my digital.

 

[barryjo]

dang...my hero has always been wonder woman, but I think running wolf is gaining ground....
If mine is off a lot..I toss it...I am waiting for my digital.

Just out of curiosity, what will you calibrate the digital one against??

 

[Pumpkinman]

Dan,
If it was off more than a point or two, I could either try to remember the discrepancy but in reality, I'd probably toss it into the hydrometer graveyard,