The term is now normally used in the United States to refer to a fortified wine made from these grapes rather than just any wine made from these grapes. This fortified muscatel became popular in the United States when, at the end of prohibition, in order to meet the large demand for wine, some poor strains of muscat grapes (used normally for table grapes or raisins) mixed with sugar and cheap brandy were used to produce what has since become infamous as a wino wine.
The term "wino wine" is used to describe a specific type of cheap, often low-quality wine that was produced during the post-prohibition era using inexpensive grapes and brandy. This wine gained notoriety for its poor quality.