Combine 1 1/2 cups amber rum (such as Appleton Estate), 1 cup Campari, and 1 cup sweet vermouth in a large pitcher; chill until very cold, at least 2 hours and up to 1 day. (epicurious.com)
I created a syrup with the yerba mate by brewing a strong batch with added sugar and used that syrup in place of vermouth in a Manhattan cocktail. (valcohol.co)
For martinis, he mixed Hendricks with dry vermouth in a Pyrex measuring cup and chilled the mixture and the glasses in the freezer until his guests arrived. (bookbrowse.com)