Home brewers use it, pro brewers use it.
You should use it, too.
This tool is called a refractometer.
It measures the specific gravity of wort by
determining how the liquid affects the bending
of light through a prism.
Due to a small viewing area, the sample amount
required is much less than the amount used
with a standard hydrometer, which relies on
buoyancy to determine gravity.
When the sample is placed on the viewing area,
and allowed to cool briefly, the plate is
put in place.
When you look through the viewfinder, you
see a line marking the split between a white
area and a blue area.
This line denotes the gravity of the wort.
Some models read in a scale called Plato,
with units of Brix.
Others read in Brix on one side, and an estimated
reading in specific gravity on the other side.
For example, in this sample, the current gravity
is approximately ten Brix.
In this sample, the current gravity is just
a bit over 3 Brix, estimated at 1.013 or 10/13
specific gravity.
With refractometers, the temperature correction
will work up to about 86F.
If your sample is hotter than this, either
be aware that the reading may be slightly
off, or all the sample to cool first.
Refractometers are handy brewing tools for
extract brewers but they are essential equipment
for partial mash, brew-in-a-bag, and especially
all grain brewers, because they allow you
to track the changing gravity of your mash
and wort during the steep and sparge, as well
as give you pre-boil and post-boil gravity
readings.
Your new refractometer is ready to go, straight
out of the box.
The factory calibrates it before it's sent
to Northern Brewer, so there's no need to
adjust it.
But if you do ever have questions about calibration,
see the instructions included inside the case.
One very important note: the refractometer
is not reading gravity necessarily.
It is reading how the light bends through
the solution.
So once fermentation begins, the reading is
distorted by alcohol.
That is to say, you can not use a refractometer
alone for determining the gravity of a beer,
wine or mead once it has begun fermenting.
The Northern Brewer website has a refractometer
calculator to help you adjust for your final
gravity.
Go to northernbrewer.com/refractometer-calculator.
Enter your original Brix reading, then enter
your Brix reading during or after the fermentation
and voila!
You have the converted specific gravity.
A refractometer is one of many tools to help
you brew better beer.
Available now at northernbrewer.com
