Alcoholic options: My preference is white wine and I use Pinot Grigio. I feel a dry white complements the soup rather than muddying it with conflicting notes the way I feel red wine does. However, in a pinch you may substitute a dry red wine, and some people like to use dry sherry or brandy or dry vermouth (I would use a splash less than the 2/3 cup called for, closer to 1/2 cup). Guinness is another option! Keep in mind that much (but not all) of the alcohol is cooked off in the cooking process. Non-alcoholic options: Substitute the wine with 1/2 cup beef or chicken broth mixed with 2-3 Tablespoons of vinegar. Some recipes substitute pure concord grape juice for the wine, and while I haven't tried it I think it would work well here.