# How To Read Hydrometer



## djrockinsteve (Nov 6, 2010)

How To Read A Hydrometer.

By taking a specific gravity reading before the introduction of your yeast to the must, then again when fermentation is complete can you determine the alcohol percentage by volume. Subtract the final reading from the beginning to get your answer.

When your hydrometer stops declining for 3 days in a row can you be certain that fermentation has ceased.

Hydrometers can contain any or all of the following scales, specific gravity, % of alcohol by vol., pounds/ounces of sugar per gallon and temperature.


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## socialdougal (Apr 22, 2015)

I just got my first set of hydrometers. There are three, they are made of glass, measure alcohol percentage, and have scales of 0-40, 40-70, and 70-100, respectively.

I've done a little home brewing from kits in the distant past, and recently decided on a whim I'd get back into it. No kits, but I have three batches of country wine and one of beer in progress. The fermentation of two appeared complete and have been racked.

Never used a hydrometer before. Can someone please advise on a minimal-mess, sanitary, efficient methodology?


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## sour_grapes (Oct 19, 2015)

Here is a good video to give a visual:

[ame="https://www.youtube.com/watch?v=ty7PAJaBsts"]https://www.youtube.com/watch?v=ty7PAJaBsts[/ame]


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## johnjmorton (Mar 13, 2018)

sour_grapes said:


> sual:
> 
> [ame="[MEDIA=youtube]ty7PAJaBsts[/MEDIA]"]


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## sour_grapes (Mar 13, 2018)

Reposting due to conversion problems with new forum:


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## Scooter68 (Mar 19, 2018)

Something I've seen a few folks miss is reading the meniscus in the hydrometer. This page gives a good and brief description of the concept. 

https://www.thoughtco.com/how-to-read-a-meniscus-606055


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## Tnawal (Jan 24, 2019)

Am I reading this correctly? 1.014


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## salcoco (Jan 24, 2019)

yes buy a digital refractometer only one drop required. adjustment spread sheets available to correct for alcohol distortion,easy peasy just read the digits.


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## cmason1957 (Jan 24, 2019)

That looks like it might be one of the plastic hydrometers. A word, not sure why, but the one I bought has now been thrown away. After about 5 or 6 batches, it started giving a very different reading than any of my glass ones, I forget now if it was reading high or low, but it was consistent, at least.


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## Tnawal (Jan 24, 2019)

Thanks, first time I am making my own wine. I did a second rack today and the kit said it should be between 1.015 - 1.025 to bottle it. I am not sure if that will be accurate because I added half the f pack at the beginning to bump up the alcohol.

I know I definitely need a longer siphon hose for the next time.


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## travelnutt (Jan 27, 2020)

So if my initial reading on the must is 1.060 and the final reading after fermentation is below 1, what is my percentage of alcohol?


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## Johnd (Jan 27, 2020)

travelnutt said:


> So if my initial reading on the must is 1.060 and the final reading after fermentation is below 1, what is my percentage of alcohol?


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## travelnutt (Jan 27, 2020)

Can I increase the % of alcohol by slowly adding sugar during the fermentation process?


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## Johnd (Jan 27, 2020)

travelnutt said:


> Can I increase the % of alcohol by slowly adding sugar during the fermentation process?



Yes, you just need to determine what you want the final ABV to be, and add the appropriate amount of sugar. It’s best to start off with the SG required to reach your ABV, but if your fermentation is already going, it can be done.


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## travelnutt (Jan 27, 2020)

Thank you. I appreviate the advice


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## ZAF (Jun 9, 2020)

I know you are not supposed to use it for wine, but has anyone used Proof and Tralle Hydrometer with wine?


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## cmason1957 (Jun 9, 2020)

ZAF said:


> I know you are not supposed to use it for wine, but has anyone used Proof and Tralle Hydrometer with wine?



This came from the great god amazon, where someone asked that exact question:



> The scale on the hydrometer reads from 0 to 100% of alcohol by volume and 0-200 percent Proof of Spirit. The hydrometer is for distilled alcohol only. It cannot be used for beer, wine or any other fermented beverage according to the label. There is also a temperature correction chart for temperatures reading below and above 60 degrees F.



And also 


> For liquors of about 40% ABV or above, this tool works fine. Below that, forget it. For instance, I bought this mainly to gauge my homemade limoncello. I make it at about 30% ABV, but when testing it this hygrometer shows a reading of less than 0% alcohol. I also tried it on a bottle of commercial butterscotch schnapps with an ABV of 20%. Same result: less than 0% alcohol.


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## ZAF (Jun 10, 2020)

Thanks @cmason1957 . I have one, so I'll report back after using it on my wine (just out of curiosity to see what happens).


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## Alexey (Aug 19, 2020)

salcoco said:


> yes buy a digital refractometer only one drop required. adjustment spread sheets available to correct for alcohol distortion,easy peasy just read the digits.


How well does the digital one work? Have you compared to hydrometer?


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## Lukaswine (Aug 20, 2020)

sour_grapes said:


> youtube.com/watch?v=ty7PAJaBsts"]





Scooter68 said:


> Something I've seen a few folks miss is reading the meniscus in the hydrometer. This page gives a good and brief description of the concept.
> 
> Know the Right Way to Read a Meniscus


I still can’t figure how
To read the final number (.996) . Not sure what the lines are equal to . Got C in chemistry...lol


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## sour_grapes (Aug 20, 2020)

The lines on the left of the photo don't line up with the tick marks with the numbers on the right. So I think you must have a "triple scale" hydrometer that shows different scales: Brix, SG, and potential alcohol. Can you post a picture showing some other views of your hydrometer, i.e., rotate the hydrometer for the picture?


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## Johnd (Aug 20, 2020)

Lukaswine said:


> I still can’t figure how
> To read the final number (.996) . Not sure what the lines are equal to . Got C in chemistry...lol


It does appear that the numbered lines aren't lining up with the graduations on the left side. I'm thinking the graduations in the picture are for the % Alchohol or Brix scale. Can you post another picture of your hydrometer, rotated a bit to the left, this time showing the full numbers (990, 1.000, etc.) and the graduations to THEIR right?

EDIT: Sorry @sour_grapes , I didn't see your response until mine posted, it was on the second page. Didn't mean to duplicate, but at least we're on the same page...............


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## sour_grapes (Aug 20, 2020)

Johnd said:


> EDIT: Sorry @sour_grapes , I didn't see your response until mine posted, it was on the second page. Didn't mean to duplicate, but at least we're on the same page...............



Wait, I thought the problem was because we were NOT on the same page!  

Seriously, that happens a lot to me. I should learn to check when the post I am responding to is the last one on a page! (But I probably won't learn  )


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## Johnd (Aug 20, 2020)

sour_grapes said:


> Wait, I thought the problem was because we were NOT on the same page!
> 
> Seriously, that happens a lot to me. I should learn to check when the post I am responding to is the last one on a page! (But I probably won't learn  )



Ahhhh, I knew you’d catch that little page play! Hopefully you’ll be able to help OP with the hydrometer graduations with a rotated hydro-pic.


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## Lukaswine (Aug 21, 2020)

sour_grapes said:


> The lines on the left of the photo don't line up with the tick marks with the numbers on the right. So I think you must have a "triple scale" hydrometer that shows different scales: Brix, SG, and potential alcohol. Can you post a picture showing some other views of your hydrometer, i.e., rotate the hydrometer for the picture?


I am posting a few photos with the hydrometer. I appreciate your comments. I am making two batches of wine this one is the Luna Rosso.


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## Lukaswine (Aug 21, 2020)

Johnd said:


> It does appear that the numbered lines aren't lining up with the graduations on the left side. I'm thinking the graduations in the picture are for the % Alchohol or Brix scale. Can you post another picture of your hydrometer, rotated a bit to the left, this time showing the full numbers (990, 1.000, etc.) and the graduations to THEIR right?
> 
> EDIT: Sorry @sour_grapes , I didn't see your response until mine posted, it was on the second page. Didn't mean to duplicate, but at least we're on the same page...............


These readings are from the second batch for Diablo Rojo


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## sour_grapes (Aug 21, 2020)

Yes, as @Johnd and I guess, you have a triple-scale hydrometer, and the tick marks you showed in your very first picture were for a different scale. The tick marks for the SG scale are on the right-hand side of your picture. It is a little hard to say without being there, but I would read your SG as about 0.998. (You should read from the bottom of the meniscus, as John often points out.)


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## Lukaswine (Aug 21, 2020)

Lukaswine said:


> These readings are from the second batch for Diablo Rojo


I’m at the stage where I supposed to add potassium metabisulphite and potassium sorbate .degass then add kieselsol


sour_grapes said:


> Yes, as @Johnd and I guess, you have a triple-scale hydrometer, and the tick marks you showed in your very first picture were for a different scale. The tick marks for the SG scale are on the right-hand side of your picture. It is a little hard to say without being there, but I would read your SG as about 0.998. (You should read from the bottom of the meniscus, as John often points out.)


thank you !


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## sour_grapes (Aug 21, 2020)

Lukaswine said:


> I’m at the stage where I supposed to add potassium metabisulphite and potassium sorbate .degass then add kieselsol
> 
> thank you !



I would say that you are _almost_ at that stage. At 0.998, you may be finished, or you may have another ~0.005 points to go. How long has it been at this SG? I would be inclined to wait another week or so.


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## Lukaswine (Aug 21, 2020)

sour_grapes said:


> The lines on the left of the photo don't line up with the tick marks with the numbers on the right. So I think you must have a "triple scale" hydrometer that shows different scales: Brix, SG, and potential alcohol. Can you post a picture showing some other views of your hydrometer, i.e., rotate the hydrometer for the picture?





sour_grapes said:


> I would say that you are _almost_ at that stage. At 0.998, you may be finished, or you may have another ~0.005 points to go. How long has it been at this SG? I would be inclined to wait another week or so.


I measured two days ago.


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## Lukaswine (Aug 21, 2020)

Do you think I should a week on both readings? I sent two reading from separate batches. I am so appreciative of your wisdom and knowledge.. Thank you, again.


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## sour_grapes (Aug 21, 2020)

The basic "rule" is that the reading should be below 0.998 or so, and unchanged for 3 days in a row. That is a decent rule, but there really isn't any reason to rush this process.


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## hounddawg (Aug 22, 2020)

sour_grapes said:


> The basic "rule" is that the reading should be below 0.998 or so, and unchanged for 3 days in a row. That is a decent rule, but there really isn't any reason to rush this process.


hey paul, i have to read mine in bright light and reading glasses, 
Dawg


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## Lukaswine (Aug 23, 2020)

sour_grapes said:


> The basic "rule" is that the reading should be below 0.998 or so, and unchanged for 3 days in a row. That is a decent rule, but there really isn't any reason to rush this process.


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## Lukaswine (Aug 23, 2020)

I will follow that rule. Thanks again.


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## Alexey (Aug 25, 2020)

sour_grapes said:


> Reposting due to conversion problems with new forum:



Thanks sour I’ve watched that video and now I know kind of how to read it. I’ll post pictures of my reading in couple days. Maybe even tomorrow. Was initially going to do it on Thursday before leaving to Vegas for my birthday.


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## Lukaswine (Aug 25, 2020)

Alexey said:


> Thanks sour I’ve watched that video and now I know kind of how to read it. I’ll post pictures of my reading in couple days. Maybe even tomorrow. Was initially going to do it on Thursday before leaving to Vegas for my birthday.


She explains how to read the hydrometer very well!


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