# hydrometers calibrations and temperatures



## shanek17 (May 24, 2012)

Hey everyone, i have a hydromerter calibrated to 68 degrees and I would like a coversion chart with a bunch of different temperatures to choose from, since temperatures can greatly differ. I did find a online calculator and tried it out. but it would be nice to have a physical chart or even a formula to use for a hydrometer. everytime i find a chart its calibrated to 60 degrees  


I actually just tested my hydrometer for calibration. and i used my digital thermometer and got the water temperature to 68.5 which is close enough to 68 and my hydrometer is reading 1.004-1.005! Its supposed to be at 1.00 rite?! like is it normal for hydros to be of a bit? i try to take care of it but admittingly the hydro has been banged around some. but now im wondering why its reading higher, and maybe my wines that iv been waiting to finish fermenting are done afterall... 

But since i found out my new calibration temperature is 1.005 can i just use that as my hydrometers calibration temp? i will evetually get a new hydrometer but for now i got just this one.


----------



## djrockinsteve (May 25, 2012)

Luc discovered that hydrometers are all over the place when it comes to accuracy. Even the manufacturers know it. I don't adjust for temp w/hydrometer.


----------



## shanek17 (May 25, 2012)

damn really. Thats brutal. how do they expect us to know when our stuff is done?! .. so buying a new one may do nothing. are they all poor quality or are some more accurate? 

well i took more accuarte samples and realized mine is calibrated exactly at 1.006. 

so i figured ill just deduct those 6 points from all my SG measurements. Im pretty sure thats all i have to do for more accurate readings. so far its making sense to me because i had one batch, for example sitting at an SG of 1.000 but if my hydro is calibrated to 1.006. i just deduct .006

so like this

SG - 1.000
- .006
= .994

so my wine that iv been waitinf to finish fermenting is looking alot better and dryer now.


----------



## Deezil (May 25, 2012)

A lot of the hydrometers come with a sheet that has the basics of how to use it as well as some rough guidelines for adjusting for temp with that particular hydrometer.

Did yours?

And yeah, hydrometers are calibrated to a lot of different temperatures, and as you've noticed, even when measured at those temps - they arent always on point. It's important to know your hydrometer in particular, and how it reads. After that (like you've done), you can make more accurate measurements.


----------



## JohnT (May 25, 2012)

Question: why is it important to have a hydormeter calibrated? If it is offf a little, what's the harm. 

The reson I ask is that I feel the wine is not rocket fuel. If the hydormeter is fairly accurate, then it seems to me that this is ok. After all, who cares is the wine is 13.6% apv as opposed to 13.7%? 

If you use a hydrometer to determine when a wine should go into a secondary fermenter, then I again question the need for a great deal of accuracy. It is not like you will be up until 4am waiting for the sg to hit a certain reading. 

Please do not take offense to the above. I do not fault folks for wanting to be percise. I just say the above to put any fears to rest. IMHO, close is just fine.

johnT.


----------



## GreginND (May 25, 2012)

JohnT said:


> Please do not take offense to the above. I do not fault folks for wanting to be percise. I just say the above to put any fears to rest. IMHO, close is just fine.
> 
> johnT.



Agreed. It's close enough for me.


----------



## Bartman (May 25, 2012)

I agree with John T. If you ignore the kit instructions that direct you to rack at a certain SG (which I believe most folks who have made a few kits choose to ignore) and instead, ferment to dry in the primary bucket, it shouldn't make a difference. As he said, 12%, 12.5%, 13% - does it really make a difference, since you can't be certain of the precise ABV without testing post-bottling anyway? If you are making you're 100th batch, using the same type of juice, yeast and ambient conditions, and you've not had any problems before, I would argue the calibration on your hydrometer really doesn't matter.


----------



## g8keeper (May 25, 2012)

+1 to everything that was said above.....yes, we are utilizing some science, sometimes without exactly knowing how and why, or that we are, in order to make wine, which is actually more of an artform in of itself....therefore PRECISION is not necessarily required....i think the adage, "close enough for government work", applies here...i think winemaking can be added to the same category as horseshoes, hand grenades, and nuclear war as the things that close only counts in....lol...


----------



## DoctorCAD (May 25, 2012)

A hydrometer could be gradated in letters and still be perfectly useful for wine making. Start at "S" and when it stabilizes at "G" for 3 days, secondary. Leave alone until it reads "B". Wine is done.

Its only a relative number start to finish, not an exact number.


----------



## robie (May 25, 2012)

I pretty much agree with all of the above. Your wine is finished fermenting not when it reaches a certain SG, but when the SG is below 1.000 and it hasn't changed for 3 days in a row. Even at that, it is still good to leave a wine in secondary for an extra week or so after the SG has not changed for 3 days.


----------



## shanek17 (May 25, 2012)

yea some good views in here for sure. i agree that some of the accuracy for what were doing does not need to be precise. like one person said this is an artform and characteristics can form from our own intuitve decisions. and even using some good ol trial and error has its place in this hobby. im not too worried abot exact alcohol % readings. As long as i have a rough idea of what it is. and that i know whether its a light wine or some heavy - one drink knock you on your *** kinda wine. hahaa

although when i want hydrometer accuracy its been important for me when finishing my wine. Like iv been checking my hydrometer and wondering why its saying my wines are at 1.002 and sitting at 1.004 for so long and im wondering if i have a stuck fermentation. but now that i know my hydrometer is calibrated not to 1.000 but to 1.006 well that makes a big difference. my wines that iv been waiting to dry out have magically dried out perfectly fine and have been sitting and waiting to be sulfited and bottled.


----------



## shanek17 (May 26, 2012)

but its not just accuracy i was kind of dissapointed too see my hydrometer not calibrated properly. as its confusing for a newbie like myself. but im wondering if maybe i banged it around too much and threw off the calibration. Or maybe i bought it like that. they seem kind of fragile and perhaps its kind of a luck of the draw when you buy one, you either get a good one or a bad one. iv worked in shipping and receiving warehouses and i know what happens to products before they get to the consumer, and i can say alot of things are not handled with care! So my question is, are some hydros made better quality than others? some day i will get a new one!


----------



## Deezil (May 26, 2012)

To those who've mentioned its not exactly necessary to be precise, i would agree.. For the most part.

The one part where you want some precision, is when it comes to replicating that favorite wine of yours. Say you have a hydrometer, and you make a killer wine - and you took all your measurements with that hydrometer... But you never checked how far it was off from "actual".

And it breaks. So you get a new hydrometer. Guess what! It has a different calibration. So whatever you backsweetened your wine to, is a mystery unless you get lucky with bench trials. 

It's not important to *always* use your adjusted SG's with every wine.. But it is important to know where your hydrometer sits in relation to 1.000.


----------



## Bartman (May 26, 2012)

Deezil said:


> And it breaks. So you get a new hydrometer. Guess what! It has a different calibration. So whatever you backsweetened your wine to, is a mystery unless you get lucky with bench trials.


Ah, yes, I suppose back-sweetened wines would require use of the hydrometer again. See, my family and friends don't care for sweet wines much at all, so it's pretty much dry reds 99 out of 100 times.
(Just between you and me, there have been a few occasions with a red kit I had made several times before, where I have checked but not recorded the SG at the start, and never checked it again - it's my secret shame!  )


----------



## g8keeper (May 26, 2012)

well i'll normally check my sg to make sure it's finished fermentation, but then when backsweetening i have just used my tastebuds as my guide....add some, stir in, draw a sample and taste....repeat until it's to my liking....i know, i know....i should then record that level to remember for next time in order to replicate....but in my case, it's been more about making different types of wine from different juices and such, and very seldom yet have i gone to doing duplicates....just like bartman, that's my secret shame....lol...


----------



## BobF (May 26, 2012)

The most accurate thing a hydrometer can tell is delta. Keep in mind that a hydrometer tells you the total amount of dissolved solids. If you use tap water to check your hydro, you aren't really standardizing it. But, it doesn't really matter +/- a few points anyway.

Why? Because the -assumption- we make when using a hydrometer is that the total reading is due to fermentable sugar. It isn't. Every must/wine is going to vary in the amount of -other- dissolved solids. You can figure anywhere from 5-10% (SWAG based on reading a jillion texts, don't ask for a cite) of the total dissolved solids to be stuff that's not fermentable sugars. And there is no way to determine what percentage is sugar using a hydrometer alone.

There are other inaccuracies such as CO2 as well ... so, the best you can hope for is a reasonable -estimate- of ABV based on the difference between SG and FG, and whether or not the ferment is either complete or stuck based on consecutive same readings.

Relax. You'll be close enough to have an idea of where your wine's ABV is relative to high/medium/low.

If you want to really nail down the alcohol content and residual sugar levels, you'll need to spend a lot of money. IMO, the money is better spent on other winemaking toys and ingredients


----------



## shanek17 (May 26, 2012)

BobF said:


> The most accurate thing a hydrometer can tell is delta. Keep in mind that a hydrometer tells you the total amount of dissolved solids. If you use tap water to check your hydro, you aren't really standardizing it. But, it doesn't really matter +/- a few points anyway.
> 
> Why? Because the -assumption- we make when using a hydrometer is that the total reading is due to fermentable sugar. It isn't. Every must/wine is going to vary in the amount of -other- dissolved solids. You can figure anywhere from 5-10% (SWAG based on reading a jillion texts, don't ask for a cite) of the total dissolved solids to be stuff that's not fermentable sugars. And there is no way to determine what percentage is sugar using a hydrometer alone.
> 
> ...


 
thanks bob, i actually used reverse osmosis water to standardize my hydro. why does tap water not work well? i called my LHBS and the ladie made a good point when i asked her about calibrating my hydro. she said she wasnt sure if my hydro is calibrated at 68 degrees in water or a dry wine. 

yea it sounds like accuracy comes with alot of expensive equipment and i agree id rather buy some more toys and ingriedients!


----------



## BobF (May 26, 2012)

RO water should give you a good read. Tap water is generally high in dissolved minerals, so not good for this kind of measurement.


----------



## ibglowin (May 26, 2012)

Distilled is still the gold standard for calibrating Hydrometers. RO water is not the same as Distilled. That said it is doubtful you would see much difference between the two reading wise with a $5 tool.


----------



## Ernest T Bass (May 26, 2012)

Kinda off the subject, but, I checked my well water with my new pH Meter, after calibrating it with 4.1 and 7.1 buffer solution and it has a 
pH of 5.6. I was expecting somewhere around 7.0. Any thoughts?
Semper Fi


----------



## ibglowin (May 26, 2012)

They doing any (oil) Fracking in your neck of the woods! Thats pretty low, but not all that uncommon really. Do you have some distilled water to try and see what it reads just to see if it comes in closer to 7?


----------



## MalvinaScordaad (May 27, 2012)

There seems to be some misconceptions that have been posted here about the Calibration and use of a hydrometer in Wine Making. Contrary to what has been said here the hydrometer is probably one of the most useful tools in a Wine Maker has in his tool kit. 

On the subject of temperature. When you are testing Brix after Crush the Must Temperature and the readings on the Hydrometer come into play. But the differences in Brix between 55 degrees and 70 degrees are not that different. What is important, actually very important, is learning the sugar content of the Must for 2 major reasons. Whether to add sugar or add water or to leave it alone. Also it is important knowing your Yeasts’s fermentation abilities as it relates to Brix and to make initial adjustments if necessary with a Must too high or too low in Brix level. This is critical. Yes you can attempt to use it at that time to estimate your alcohol content when fermentation is complete but if you research Brix charts and ABV you will discover that an accurate prediction is not reality.

As far as Calibration goes it makes no sense to think you are accomplishing anything worthwhile calibrating with distilled water attempting to come to a conclusion of calibration at zero brix. First, inexpensive hydrometers are not always accurate. But even if they are, a reading at zero brix in distilled water is a waste of time. The reading and calibration you want is at 25 brix. That is where most of the errors show up. And for the reasons stated above a reading of 23 or 25 may change a winemaker’s decision whether to add water or add sugar. That is why testing and determining a calibrating factor for your hydrometer at 25 Brix is what you need to do especially when using the garden variety hydrometer. 

There are two ways to calibrate your hydrometer. One is to buy a Laboratory Standard Calibrated Hydrometer (about 50 dollars) and use that against your other inexpensive one and determine a plus or minus factor to use prior to fermentation. This way you can keep your Lab Standard Hydrometer safe and use the inexpensive one. The other way is to purchase 25 brix lab standard solution. Then you can determine the error at 25 brix in your hydrometer and record a correction factor to use. 

The use of the Hydrometer during fermentation is also important for a few reasons. While total accuracy is less important, you will want to have a good idea of brix level at various stages to determine nutrient addition staging and tracking fermentation progress. One example could be avoiding adding any product with DAP in the Must below 10 brix another could be determining the fermentation speed and the need to raise or lower heat, or add a non DAP containing nutrient in later stages of fermentation. A dividing by half of Brix level in 24 hours in fermentations below 8 brix demonstrates a healthy fermentation. Less than that indicates a slowing down that needs to be watched carefully. When reaching 5 brix it is a good idea to use a small scale hydrometer with a Plus 5 –Negative 5 scale. It is much easier to read. At this time you can determine if your Brix is low enough ( 2 brix of lower) to consider adding ML Bacteria if you wish before you press. Also it will be able to read below zero as fermentation completes. However it is no indicator of a finished fermentation. Alcohol Content and other factors affect the reading below zero. So it is quite possible to read a minus 1 and still have remaining sugar to ferment. A better way through observation after pressing is to observe any bubble activity in a carboy with the wine held at 70-75 degrees for a few weeks. Of course if you are doing a Malolactic Fermentation both would be happening at the same time so it would be hard to tell. Another way is to employ a Clinitest. It will give you a very good idea of residual sugar in your wine so when testing for Malic Acid content you can test for residual sugar as well. 

One thing don’t bother testing distilled water ph since it does not have any ions for the PH Meter to work with. 

Hopes all of this helps you out Shane.


----------



## ibglowin (May 27, 2012)

Freshly distilled water should have a pH of 7.0. However, interaction with the atmosphere allows carbon dioxide to dissolve into it, forming carbonic acid. As a result, agitating the water or allowing it to sit for a while will leave you with an aqueous solution that drifts down in pH. Because there are no natural buffers in distilled water, the pH can go down as low as 5.0.



MalvinaScordaad said:


> One thing don’t bother testing distilled water ph since it does not have any ions for the PH Meter to work with.


----------



## MalvinaScordaad (May 27, 2012)

ibglowin said:


> Freshly distilled water should have a pH of 7.0. However, interaction with the atmosphere allows carbon dioxide to dissolve into it, forming carbonic acid. As a result, agitating the water or allowing it to sit for a while will leave you with an aqueous solution that drifts down in pH. Because there are no natural buffers in distilled water, the pH can go down as low as 5.0.


Whether it is dissolved Co2, the lack of Ions, or the ability of type of probe, there is no value in using distilled water to check the calibration of a PH Meter. It seems the problem is greater than just carbonic acid. 

From Orion Research Inc. 
Conventional pH electrodes, which are designed to function in high-conductivity solutions, show slow and erratic response in pure water samples such as acid precipitation. Increasing conductivity without shifting pH solves the measurement problem. This method correctly measures pH in low conductivity solutions, using a Ross combination pH electrode, after the addition of a small amount of potassium chloride (KCl) solution to the sample. The Ross electrode, with its unique internal redox system, is chosen since it eliminates problems associated with temperature and because the precision and accuracy of data obtained in preliminary testing with it were comparable to those obtained with the standard hydrogen electrode. KCl addition to samples does not alter the pH significantly.


----------



## djrockinsteve (May 27, 2012)

I do not calibrate or check it myself. I take a reading and record it. Done.


----------



## BobF (May 27, 2012)

Same here Steve. I find the hydro to be invaluable. I just don't think ABV determination with a hydro is accurate.

Long live hydrometers!


----------



## Deezil (May 27, 2012)

MalvinaScordaad said:


> _As far as Calibration goes it makes no sense to think you are accomplishing anything worthwhile calibrating with distilled water attempting to come to a conclusion of calibration at zero brix. First, inexpensive hydrometers are not always accurate. But even if they are, a reading at zero brix in distilled water is a waste of time *(1)*_. _The reading and calibration you want is at 25 brix *(2)*._ That is where most of the errors show up. And for the reasons stated above a reading of 23 or 25 may change a winemaker’s decision whether to add water or add sugar. That is why testing and determining a calibrating factor for your hydrometer at 25 Brix is what you need to do especially when using the garden variety hydrometer.
> 
> There are two ways to calibrate your hydrometer. One is to _buy a Laboratory Standard Calibrated Hydrometer (about 50 dollars) *(3)*_ and use that against your other inexpensive one and determine a plus or minus factor to use prior to fermentation. This way you can keep your Lab Standard Hydrometer safe and use the inexpensive one. The other way is to purchase 25 brix lab standard solution. Then you can determine the error at 25 brix in your hydrometer and record a correction factor to use.



1 - I would just like to see proof. (proof: documentation from a college or 'accredited' wine association... random websites, i have a hard time believing all the time.. i take most everything with a grain of salt)

2 - First time i've heard this.. Hence wanting to see proof of #1

3 - I looked into these... and even the directions that come with them, specifically mention using distilled water to make sure the hydrometer is accurate. I looked at several different types (those used in oil, for example), through several different manufacturers, on several different websites. And they all said the same thing.

The theory of what you said, sounds alright.. But proof would seal the deal. Everything i've read thusfar, speaks of distilled water to calibrate at for 1.000


----------



## MalvinaScordaad (May 27, 2012)

If you want proof then that is very easy test 3 inexpensive hydrometers at O brix and then at 25 brix. The major differences occur at the top of the scale not at the bottom. And those errors are more significant to the winemaker when making amelioration or chaptalization decisions. Documentation is sometimes the best when you discover it for yourself.


----------



## Deezil (May 27, 2012)

MalvinaScordaad said:


> If you want proof then that is very easy test 3 inexpensive hydrometers at O brix and then at 25 brix. The major differences occur at the top of the scale not at the bottom. And those errors are more significant to the winemaker when making amelioration or chaptalization decisions. Documentation is sometimes the best when you discover it for yourself.



The only thing that would show me is that the amounts that inexpensive hydrometers are off at 0 Brix, would then be compounded at 25 Brix. It wouldnt make measuring hydrometers with distilled water obsolete. 
Edit: So i thought about this a little more... And honestly, would it compound? Or would it be off by the same degree either way? Talking about TDS in a liquid, my heads having a hard time wrapping around it because i cant actually *see it* 

So you're right, in that the major differences will be at the top-end of the scale. That'll i'll give you. But it also wasnt what i wanted to see proof of.

You said measuring inaccuracies in inexpensive hydrometers is 'a waste of time' using distilled water. So far, the evidence suggests that clearly its not. The manufacturers, the vendors, the customers - they all say the same thing...

I guess there's always 'two ways to skin a cat'


----------



## MalvinaScordaad (May 27, 2012)

Skin a cat anyway you wish but what is really important to the wine maker is using the accuracy of the reading at the beginning of the fermentation. What difference does it really make at 0 or minus 1 or 2 when that reading is more effected by Alcohol Content than actual remaining sugar content. What is important at the beginning is Sugar Content. At the end of fermentation a small scale hydrometer is more useful in seeing 24 hour changes in levels to determine continued fermentation. But using the Hydrometer to determine actual completion of all sugar fermentation is not really possible. Whether it is calibrated at zero or not. Why bother calibrating at zero with distilled water when you really are interested in the calibration at 25 Brix when it matters. It seems pretty obvious your are calibrating at the wrong end of the scale in any case. 

As to your question the answer is no. They are off much more at 25 brix than at zero. And Manufactures take the easy route here and tell you to test at Zero. As far as customers are concerned, many here, have never heard of a Lab Standard Calibrated Hydrometer or for that matter 25 Brix lab standard solution used primarily to adjust Refractometers. If we used your argument why not adjust your Refractometer with distilled water. It doesn't work that way. That's why.


----------



## Deezil (May 28, 2012)

MalvinaScordaad said:


> Skin a cat anyway you wish but what is really important to the wine maker is using the accuracy of the reading at the beginning of the fermentation. What difference does it really make at 0 or minus 1 or 2 when that reading is more effected by Alcohol Content than actual remaining sugar content. What is important at the beginning is Sugar Content.



I'll skin a cat while it's still screaming if i feel like it, have you no fear in that. 

You stress the importance of the accuracy in the initial reading, but downplay the importance of a final reading. Hydrometers measure more than just the sugar in the solution - which im sure we both know because you've also pointed out. So the accuracy you stress in the beginning, is theoretically thrown off just like your final readings, albeit by a different cause. 

Alcohol content, however, affects a hydrometer reading in the opposite way than the sugar content would because alcohol is less dense than water - this would make it sink farther & read a lower number (This opposite-reaction could possibly negate some/all of the inaccuracy in a hydrometer, but that's only theoretical and not something we could readily test). While, obviously, sugar would be adding more TDS to the liquid therefor making it more dense - raising the hydrometer.



MalvinaScordaad said:


> Why bother calibrating at zero with distilled water when you really are interested in the calibration at 25 Brix when it matters. It seems pretty obvious your are calibrating at the wrong end of the scale in any case.



Honestly, you've left me scratching my head here. _Obviously_ its not very obvious, or we wouldn't be having this conversation would we? 



MalvinaScordaad said:


> As to your question the answer is no. They are off much more at 25 brix than at zero. And Manufactures take the easy route here and tell you to test at Zero. As far as customers are concerned, many here, have never heard of a Lab Standard Calibrated Hydrometer or for that matter 25 Brix lab standard solution used primarily to adjust Refractometers.



So then you're saying the inaccuracy at 0Brix is compounded when you reach 25Brix. By what degree, who knows.. But compounded nonetheless.



MalvinaScordaad said:


> If we used your argument why not adjust your Refractometer with distilled water. It doesn't work that way. That's why.



If you dont use distilled water, what do you use? I could see an argument for 2-point calibration (distilled water & 25Brix) over a single-point... But lemme guess, you only use a 25 Brix solution for your refractometer too?


----------



## altavino (May 28, 2012)

In the oenology program I attended at Curtin University , we were taught to calibrate hydrometers at 25 brix . using a solution of 250 grams of sugar measured on a digital scale made to a litre of water .

one thing to keep in mind is that hydrometers are not absolutely accurate as others have stated , neither is a refractometer . its hard to be absolutely accurate with a hyper complex solution such as must. (hyper complex meaning there are many ingredients other that sugar and water and many of those same ingredients are in a state of chemical transition or flux) 

Zac put it best when he said " a hydrometer is a sundial not an atomic clock"

you don't need it to be absolutely accurate , otherwise if you did you'd be pulling samples and running off to a mass spectrometer and gas chromatograph every day. hydrometers and refractometers are feild tools which are "close enough" for our needs.

anyway one of my profs explained measuring brix as being most important preferment so you can make adjustments , after that you are just tracking the dropping movement of the sugars being consumed to ensure that you are not dealing with a stuck ferment. then when you think its dry and the hydrometer indicates this. he said to run a confirmation test to be sure such as a clintest. probably overkill for a home winemaker but the point is commercially you run a second test to confirm dryness .
often you also send a sample to a lab for a full panel , which tests for a range of things , including residual sugar, such is the lack of trust in the final reading, which would indicate clibration is best done at the start , and 25 brix is closer to that end.


here is a good set of fermentation calculators which may help your fermentations 

http://vinoenology.com/calculators/fermentation/


----------



## MalvinaScordaad (May 28, 2012)

Deezil said:


> I'll skin a cat while it's still screaming if i feel like it, have you no fear in that.
> 
> You stress the importance of the accuracy in the initial reading, but downplay the importance of a final reading. Hydrometers measure more than just the sugar in the solution - which im sure we both know because you've also pointed out. So the accuracy you stress in the beginning, is theoretically thrown off just like your final readings, albeit by a different cause.
> 
> ...



While you are skinning that cat again , yes the alcohol does affect the readings as it increases in the must but what is important is the reading when there is no alcohol present. That is the most important reading. As Altavino has just said after that the reading is tracking the reduction of sugar. You are not tracking the increasing alcohol. And when you get to close to the end of the sugar depletion the Alcohol effect has more bearing on the reading. That inaccuracy in the hydrometer's ability,due to other components in the wine, to measure a completed fermentation of any remaining sugar is why you can be Dry at minus .5 or not dry at minus 1. 

But you make the case of calibrating at the point where you can't trust the reading you are trying to make and which, while you might want to know when the sugar is no longer present, the device you want to use is incapablle of actully determinging that in the first place. 

Common sense not a College Class tells you to calibrate a tool to make a reading where that reading is most important. Not at the opposite end of the scale where the error can only be compounded. That is the obvious part of the discussion. 

On practical level you, since Altivino has just provided you with a formula to make a 25 brix solution, can test your own hydrometers. You can still test at 0 with distilled water only to see if they read correctly at that end of the scale. Unlike the serious importance of accuracy in the 26 to 22 range where decisions have to be made, it matters very little at the opposite end since in the range of 0 to minus 2 you can still have unfermented sugar and an incomplete yet still active fermentation. In my experience I have 4 hydrometers that cost less than 20 dollars and 1 that is a Certified Lab Standard Hydrometer. Only the lab standard reads correctly at 25 brix. The others read anywhere from 22 to 27. All of them read 0 in distilled water. 

Where a Home wine maker and a Commercial winemaker part company could be another discussion. As to overkill, and not relying on the Sun Dial, the 35 dollar Clinitest kit is not really overkill in my mind if you are truly interested in determining a completed sugar fermentation. One thing is for sure though as the Professor said, the hydrometer is not the answer for that no matter how much distilled water you use.


----------



## BobF (May 28, 2012)

Mal (can I call you that?),

I agree with you that the upper end is the best place to calibrate. IIRC, Luc posted a link to an article some time ago regarding hydro calibration and varying degrees of accuracy amongst the common hydrometers sold for home winemaking.

The best reason I can think of for calibrating (standardizing?) at the starting range is that the errors are likely not linear. At the very least, it would incorrect to assume a constant offset without verifying.

Anyone interested in this topic would be doing well to find/read Luc's article.

Even standardized at 25 brix, there is still a large assumption being made - that fermentable sugar is the only dissolved solid contributing to the reading. I'm not saying one shouldn't try to be as accurate as possible - this is, after all, an industry standard assumption. I'm simply trying to dispel the notion that a hydrometer reading will nail things to within a gnats *** width.

I feel the time I would spend separating fly dung from pepper would be better spent elsewhere in the process


----------



## MalvinaScordaad (May 28, 2012)

Yes dear you can call me Mal. 

Yes I think that the errors are not linear and assuming a constant offset would be a leap of faith. Furthermore you are correct about the readings at the crush. There are a lot of factors that can affect the results. There are a few methods to minimize that. One is settled juice but that is not perfect as some sugars are contained in the grapes and not fully dissolved. I have also noticed that there can be a considerable bump up in Brix after Cold Soak and during lag phase. But you have to make a decision at some point if you plan on taking any external action. At least trusting the hydrometer to be accurate to itself is a good starting point. 

The original poster was expressing considerable frustration with trying to use the hydrometer to determine the end of fermentation. He said ,*"damn really. Thats brutal. how do they expect us to know when our stuff is done?! .. * I think that is funny. They don't expect anything Shane. As a Winemaker it is up to you to figure it out. The best advice to give you Shane, failing to use a Clinitest, is to keep the hydrometer in the drawer after the level stops dropping, store your wine warm for 3-4 weeks at 75 degrees and observe any activity in the neck of the carboy.


----------



## whackfol (May 28, 2012)

Wow, 30 posts in four days -- I had to read them all. I'm from the school that no matter how calibrated, the hydrometer is only a tool to gauge and adjust the starting Brix and monitor fermentation. (During fermentation I'm more concerned with the temperature and with the timing of my additions). In the end, I use the Clinitest to measure residual sugar. The level of accuracy I require is more than offset by the variability of the sugar vs non sugar solids in the must and the variability of PA estimates based on beginning BRIX. 

As to the hydrometer, they are used heavily at my place of work. I had a quick conversation with our head scientist about the use and calibration of hydrometers. I don't pretend that I fully understand what was said. What I do know is he busted many of my assumptions and methodologies. For instance, I consider "pure water" as distilled or deionized. In his world there is a spec for water that includes conductivity, maximums of chlorides, silicas, sodium and other minerals. Temperature is a big issue in measurement of BRIX. However, how many of us have a calibrated thermometer? I have a few "good quality" thermometers purchased from lab supply stores. None is within 3/10 of a degree C. He sends his hydrometers out to be calibrated to a NIST standard. Typically this includes different test methodologies. In house he uses three point calibration (none zero) with non-sugar standards approved by NIST. He would never use a single point reference for hydrometers, pH meters and many other items in his lab. So far we have discussed the viscosity of the liquid, I learned that the barometric pressure will affect a reading.

For my purpose (wine making) he recommended calibrating 1) using distilled water for zero, 2) using a sugar mixture that is in the 50% range of my hydrometer and 3) one that is 90% of my hydrometer scale. His rationale is that the paper scale in hydrometers may not be accurate across the entire scale and shock to the instrument can jar the paper scale. Above all, he recommended calibrating my thermometer and taking careful measurement of temperature for temperature correction.


----------



## shanek17 (Jun 16, 2012)

okay so I tried keeping up with this thread but you guys went way over my head with hydrometers. I ended up going out and getting a new one from the same store but this one is a little different , this one is calibrated to 60F instead of 68F. I actually have a question though about how to properly read it . The instructions look confusing so Im taking a picture now to show you all. So the picture says reading below meniscus , which makes me think they are saying to take the reading below the water climbing up around the hydrometer. But if that is true then why in the picture do they show it being measured at 1010? 

so I have posted both instructions for my 2 hydrometers, the first picture is for the hydro that is calibrated to 60F and the second instructions with the green water are from the 68F hydro. Its just weird that they say to read either above or below.


----------



## Runningwolf (Jun 16, 2012)

Always read below. The actual readings would be 1.000 or 1.010 It will save you a lot of grief later to use the decimal point and expand out 3 digits. It will also help us understand where your readings are at as you ask questions. This was something I also had to get use to and most beginners do. Heck there are even people who have been making wine for years and don't even know what a hydrometer looks like. Keep asking and we'll walk you through anything.


----------



## JordanPond (Jun 16, 2012)

The most important practice would be to be concistent when taking a reading. Always read above or always read below. That prevents you from introducing an error.


----------



## BobF (Jun 17, 2012)

I also have hydros with different temps and instructions for reading. I always follow the instructions specific to the individual hydrometer.


----------



## shanek17 (Jun 17, 2012)

What im still confused about is the black and white instructions are showing a reading at 1010. does that mean its calibrated at 1010?


----------



## BobF (Jun 17, 2012)

I'm sure the illustration in the instructions is just an example of how to read it.


----------



## shanek17 (Aug 16, 2012)

Hey another question here, Maybe this is simple but im confused about the hydrometer and its markings. When I look at my hydro it has 0% alcohol listed at the 1.000 marking. But often times our alcohol drys out below 1.000, to as low as .990. So how can it go below 0%?


----------



## MalvinaScordaad (Aug 16, 2012)

The presence of Alcohol allows the hydrometer to sink further than distilled water at 0


----------



## Runningwolf (Aug 17, 2012)

In addition to what Malvina said, remember the alcohol reading on your hydrometer is only for potential alcohol and is meant to be read before fermentation begins. This is to help you determine how much sugar you want to add to reach your alcohol target.


----------



## Boatboy24 (Aug 17, 2012)

Runningwolf said:


> In addition to what Malvina said, remember the alcohol reading on your hydrometer is only for potential alcohol and is meant to be read before fermentation begins. This is to help you determine how much sugar you want to add to reach your alcohol target.



And that percentage assumes you will only ferment to 1.000. Since we frequently go well below that, I ignore the potential alcohol amount.


----------



## shanek17 (Aug 18, 2012)

Boatboy24 said:


> And that percentage assumes you will only ferment to 1.000. Since we frequently go well below that, I ignore the potential alcohol amount.




Okay, so just to clarify, if I want to use the potential alcohol meter on the hydrometer when mixing my must then the wine has to stop ferementing at 1.000 for the PA % to be corrent. Is that rite?


----------



## Brew and Wine Supply (Aug 18, 2012)

Its amazing that any of them are accurate after haveing them shipped halfway across the country packed on a pallet in the back of a big rig for three to four days. \
and thats not counting what they went through before I ordered them.


----------



## MalvinaScordaad (Aug 18, 2012)

Brew and Wine Supply said:


> Its amazing that any of them are accurate after haveing them shipped halfway across the country packed on a pallet in the back of a big rig for three to four days. \
> and thats not counting what they went through before I ordered them.


Then maybe you should test them with 25 brix lab standardized solution before you sell them. Ya think?
Malvina


----------



## BobF (Aug 18, 2012)

shanek17 said:


> Okay, so just to clarify, if I want to use the potential alcohol meter on the hydrometer when mixing my must then the wine has to stop ferementing at 1.000 for the PA % to be corrent. Is that rite?



Your hydrometer should have included instructions. Most provide examples, and give you tables that tell how additional 'PA' to add when the reading goes below 1.000.

Every 7.36 gravity = 1% alcohol. This is the reason I prefer using the gravity drop to calculate abv. The different ways to calculate give slightly different results. I use (SG - FG)/7.36.

Ex.
SG = 1090
FG = 990

1090 - 990 = 100
100 / 7.36 = 13.58

If you plug the numbers into FermCalc, it will display the results for several of the most popular methods.

http://web2.airmail.net/sgross/fermcalc/FermCalcJS.html

To finally answer your question directly, yes, the PA scale is based on 1.000 being zero. However, most ferments will end with readings lower than this.


----------



## Brew and Wine Supply (Aug 18, 2012)

MalvinaScordaad said:


> Then maybe you should test them with 25 brix lab standardized solution before you sell them. Ya think?
> Malvina


 
I'll get right on it.


----------

