Agriculture Reference
In-Depth Information
The key to getting the sugar right is using a hydrometer. The
hydrometer was discussed briefly in the previous chapter. As
stated, it looks a lot like a thermometer with a big bulb on the
end. It measures the amount of dissolved solids in a solution
by how far it sinks. There is a long stem and a scale, and the
specific gravity is read where the liquid touches the glass.
This is important because the surface tension of the liquid will
give a false reading anywhere else, so be sure to read the
value where the liquid is touching the glass.
I use a wine thief that doubles as a hydrometer jar. So I clean
and sanitize the wine thief and hydrometer, and then give the
hydrometer a spin as I put it into the liquid. Giving the
hydrometer a spin is necessary because otherwise air bubbles
could cling to it and give it false buoyancy that would give
inaccurate readings.
Using the weight method of determining specific gravity.
Once you have your reading, you will need to correct it to
compensate for the temperature of the must, because
hydrometers are calibrated for 60 degrees. If the temperature
is between 40 and 50 degrees, subtract 0.002 from the
reading. If the temperature is between 50 and 55 degrees,
subtract 0.001. If the temperature is between 65 and 75, add
