hist-brewing: Ovular hydrometer.

Charley Atchley Charley at lcc.net
Tue Nov 20 20:14:19 PST 2001

>i think the egg needs to float about 3/4 of an inch above the water.


I have calibrated eggs with salt water. Start adding salt to a 2 cup
measuring cup of water. When the egg floats to the right height, pull it out
and pour the water into your graduated cylinder, then use the hydrometer to
measure it.

The egg was a common hydrometer all the way into the 1900s. I have seen it
used in beef jerky, beer, maple syrup, wine, mead and hog feed supplement

These are my numbers. Eggs tend to change with age, size (jumbo verses
small), freshness and whether they are yard eggs or factory farm eggs.
The various degrees seem to be:
Till the egg starts to stand up off bottom    1.035
Till the egg is standing straight up on the bottom   1.053
Till the egg suspends, neither floating nor sinking 1.062
Till the egg touches the surface 1.070
Till the a half inch circle is floating clear 1.081
Till a 3/4 circle is floating clear  1.098
Till a one inch circle is floating clear. 1.122
Till a one and a quarter inch circle is floating clear 1.131
Till the egg stops floating vertical 1.155
Till the egg makes an oval that is one and a quarter by one and a half
floating clear 1.180

On the last one the egg is only sticking about a quarter of an inch out of
the water. I do not think it would be possible to get the egg to float 3/4
of an inch above the solution using salt. That would however be a specific
gravity that is drastically above brewing ranges.

Most of the time, they are talking about the diameter of the part sticking
out of the fluid, not the height.

Athaulf Sweinbrothar
If you must choose between two evils, pick the one you've never tried

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