Meaning of BEAD PROOF in English

BEAD PROOF

a degree of strength in alcoholic liquor as shown by beads or small bubbles remaining on its surface, or at the side of the glass, when shaken.

2. bead proof ·- among distillers, a certain degree of strength in alcoholic liquor, as formerly ascertained by the floating or sinking of glass globules of different specific gravities thrown into it; now ascertained by more accurate meters.

Webster English vocab.      Английский словарь Webster.