From time to time we receive calls regarding the use of
the hydrometer: about how a reading is actually taken;
what the readings actually mean and so on. Let's face
it, unless you've used a hydrometer before it is
somewhat of a foreign concept. I will attempt to clear
up some of the confusion here.
What the hydrometer can do for you is two-fold. First,
it allows you to track the progress of your fermentation
by taking readings throughout the fermentation.
Secondly, it can tell you what the alcohol percentage of
your finished product is by taking a reading before
fermentation and one after fermentation and comparing
the two.
How To Take A Hydrometer Reading
To take a reading with the hydrometer it is required
that you get the hydrometer to float in the juice to be
tested. Weather it is floating in the plastic tube it
came in, in a test jar you purchased, or floating in the
entire batch makes no difference, as long as it is
floating you will be able to take a reading.
Once the hydrometer is floating, you take the actual
reading by seeing where the surface of the liquid
crosses the scale on the hydrometer.
Different Scales On The Hydrometer
Typically, there are two scales on the hydrometer that
you are concerned with: the "Specific Gravity" scale
(normally labeled as S.G. or SP GR) and the "Potential
Alcohol" scale.
Specific Gravity is referred to by most books and
recipes. It is simply a scale based on the weight of
water. The "Potential Alcohol" scale is used to easily
determine how much alcohol was made or can be made.
Learning About The "Specific Gravity" Scale
Just for fun, if you float the hydrometer in water and
read the Specific Gravity scale, the surface of the
liquid would cut across the hydrometer at the 1.000
mark, towards the top of the scale. Most hydrometers are
calibrated to be most accurate at 60 degrees Fahrenheit.
So, if the water is warmer or cooler, the reading may be
off just a hair.
When you take a reading in fruit juice or water that has
had sugars added to it, the hydrometer will float higher
than before. This is because the liquid is now heavier
than water which in turn increases the buoyancy of that
liquid.
For example, it you completely dissolve 2 pounds of cane
sugar into 1 gallon of water, you will have a Specific
Gravity reading of 1.068. You will find this on the
Specific Gravity scale by going down from the 1.000 to
the 60. The 60 represents 1.060. In between the 60 and
70 you will see several tick marks. Each one represents
two points. So, the fourth tick would be the 8. This is
the point on the hydrometer that represents 1.068.
Learning About The "Potential Alcohol" Scale
If you put your thumbnail at the 1.068 mark mentioned
above and roll the hydrometer around to the Potential
Alcohol scale you will see it matches a reading of 9%.
What this means is that if you where somehow able to get
this liquid to ferment all of the sugars it contained
into alcohol, the result would be a liquid with 9%
alcohol by volume.
As the wine ferments you will see the Potential Alcohol
reading becoming lower and lower. What this means is
that as the sugars in the juice are turned into alcohol
the potential for more alcohol is reduced.
To find out what the actual alcohol percentage of a
finish wine is, you would subtract the ending
fermentation reading from the beginning fermentation
reading.
Typical Example Of Hydrometer Use
For example, lets say you have 5 gallons of freshly
pressed grape juice. You take a beginning reading of 12
percent on the Potential Alcohol scale of your
hydrometer. When the fermentation is complete, you take
another reading with the hydrometer that indicates a
Potential Alcohol of 1 percent. You then take the 1 and
subtract it from the 12, giving you a total of 11
percent alcohol. This means that the fermented juice now
has 11 percent alcohol by volume.
In Conclusion
If you are not currently using a hydrometer, I would
suggest that you might consider using one in the future.
While it may be a little intimidating at first, once you
use one you'll soon discover that there is not much to
it. The benefit is the hydrometer allows you to have
much more control over your batches. With the hydrometer
you can control the alcohol content of your wines,
monitor the fermentation's progress, as well as
determine when the wine is actually done fermenting.
* To view the hydrometers we have right now on our web
site go to:
From time to time we receive calls regarding the use of
the hydrometer: about how a reading is actually taken;
what the readings actually mean and so on. Let's face
it, unless you've used a hydrometer before it is
somewhat of a foreign concept. I will attempt to clear
up some of the confusion here.
What the hydrometer can do for you is two-fold. First,
it allows you to track the progress of your fermentation
by taking readings throughout the fermentation.
Secondly, it can tell you what the alcohol percentage of
your finished product is by taking a reading before
fermentation and one after fermentation and comparing
the two.
How To Take A Hydrometer Reading
To take a reading with the hydrometer it is required
that you get the hydrometer to float in the juice to be
tested. Weather it is floating in the plastic tube it
came in, in a test jar you purchased, or floating in the
entire batch makes no difference, as long as it is
floating you will be able to take a reading.
Once the hydrometer is floating, you take the actual
reading by seeing where the surface of the liquid
crosses the scale on the hydrometer.
Different Scales On The Hydrometer
Typically, there are two scales on the hydrometer that
you are concerned with: the "Specific Gravity" scale
(normally labeled as S.G. or SP GR) and the "Potential
Alcohol" scale.
Specific Gravity is referred to by most books and
recipes. It is simply a scale based on the weight of
water. The "Potential Alcohol" scale is used to easily
determine how much alcohol was made or can be made.
Learning About The "Specific Gravity" Scale
Just for fun, if you float the hydrometer in water and
read the Specific Gravity scale, the surface of the
liquid would cut across the hydrometer at the 1.000
mark, towards the top of the scale. Most hydrometers are
calibrated to be most accurate at 60 degrees Fahrenheit.
So, if the water is warmer or cooler, the reading may be
off just a hair.
When you take a reading in fruit juice or water that has
had sugars added to it, the hydrometer will float higher
than before. This is because the liquid is now heavier
than water which in turn increases the buoyancy of that
liquid.
For example, it you completely dissolve 2 pounds of cane
sugar into 1 gallon of water, you will have a Specific
Gravity reading of 1.068. You will find this on the
Specific Gravity scale by going down from the 1.000 to
the 60. The 60 represents 1.060. In between the 60 and
70 you will see several tick marks. Each one represents
two points. So, the fourth tick would be the 8. This is
the point on the hydrometer that represents 1.068.
Learning About The "Potential Alcohol" Scale
If you put your thumbnail at the 1.068 mark mentioned
above and roll the hydrometer around to the Potential
Alcohol scale you will see it matches a reading of 9%.
What this means is that if you where somehow able to get
this liquid to ferment all of the sugars it contained
into alcohol, the result would be a liquid with 9%
alcohol by volume.
As the wine ferments you will see the Potential Alcohol
reading becoming lower and lower. What this means is
that as the sugars in the juice are turned into alcohol
the potential for more alcohol is reduced.
To find out what the actual alcohol percentage of a
finish wine is, you would subtract the ending
fermentation reading from the beginning fermentation
reading.
Typical Example Of Hydrometer Use
For example, lets say you have 5 gallons of freshly
pressed grape juice. You take a beginning reading of 12
percent on the Potential Alcohol scale of your
hydrometer. When the fermentation is complete, you take
another reading with the hydrometer that indicates a
Potential Alcohol of 1 percent. You then take the 1 and
subtract it from the 12, giving you a total of 11
percent alcohol. This means that the fermented juice now
has 11 percent alcohol by volume.
In Conclusion
If you are not currently using a hydrometer, I would
suggest that you might consider using one in the future.
While it may be a little intimidating at first, once you
use one you'll soon discover that there is not much to
it. The benefit is the hydrometer allows you to have
much more control over your batches. With the hydrometer
you can control the alcohol content of your wines,
monitor the fermentation's progress, as well as
determine when the wine is actually done fermenting.
* To view the hydrometers we have right now on our web
site go to:
