vinometer

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A hydrometer used to determine the percentage of alcohol in a wine.

from The Century Dictionary.

• noun A contrivance for measuring the alcoholic strength of wine.

from the GNU version of the Collaborative International Dictionary of English.

• noun An instrument for determining the strength or purity of wine by measuring its density.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A device used to estimate the alcohol content of wine via its surface tension (in the absence of sugar)